<![CDATA[Jatan's Space: Space Tech 🛰]]>https://blog.jatan.space/s/space-techhttps://cdn.substack.com/image/fetch/w_256,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fbucketeer-e05bbc84-baa3-437e-9518-adb32be77984.s3.amazonaws.com%2Fpublic%2Fimages%2F9093a5d3-2247-45af-afa9-14b879f2386a_600x600.pngJatan's Space: Space Tech 🛰https://blog.jatan.space/s/space-techSubstackFri, 03 Dec 2021 16:38:39 GMT<![CDATA[A brief history of space missions lost to human errors]]>https://blog.jatan.space/p/space-missions-lost-to-human-errorshttps://blog.jatan.space/p/space-missions-lost-to-human-errorsFri, 22 Oct 2021 13:06:59 GMTA space mission is an immensely complex undertaking. Hundreds to thousands of people from several distinct fields of expertise must come together to orchestrate thousands of moving parts and functions to make a space machine behave as expected. As such, failure to communicate or get right even a seemingly miniscule mission aspect can lead to cascading effects that can and have resulted in mission loss.

Here’s a brief history of some major missions lost because of very avoidable human errors, and which aren’t programmatic failures like the Space Shuttle.

Mariner 1 blows up

On July 22, 1962, an Atlas rocket launched successfully with NASA’s Mariner 1 spacecraft encapsulated in its fairing. NASA had hoped to be the first to successfully flyby Venus and counter the Soviet Union’s lead in the Space Race. Less than five minutes into the flight, it was clear Mariner 1 wouldn’t even reach Earth orbit.

A range safety officer tracking the rocket’s flight detected an unexpected yaw-lift (northeast) maneuver, meaning its guidance system faltered. The rocket was unable to steer itself as intended, and was heading towards a crash, either in the North Atlantic shipping lanes or worse, in an inhabited area. The officer had no choice but to order the destructive abort. The rocket along with Mariner 1 exploded, and $80 million dollars ($720 million in 2021) gone.

It turned out that a programmer had left out a hyphen out of an equation while entering its hand-transcribed code into the rocket’s computer. This fed false information to the guidance system and ultimately all that was left was debris. The human error was fixed for Mariner 2, which launched shortly after and conducted the first successful flyby of Venus.

Phobos 1 goes haywire

In 1998, the Soviet Union launched the ambitious Phobos 1 spacecraft to study Mars’ moons and land a probe on the largest of them, Phobos. But the mission was doomed before it could even reach Mars. On September 2 of that year, mission operators lost contact with the spacecraft and never heard back after.

An investigation of prior commands sent to the spacecraft revealed that software uploaded on August 29 missed a single character. This put the spacecraft in a steering test mode—usually only done on Earth—which also deactivated the spacecraft’s attitude thrusters. Phobos 1 could no longer orient its solar arrays towards the Sun. When it ran out of battery power, communication with it was lost. The flight software thus contained code that was supposed to be removed after testing on Earth. Moreover, the spacecraft’s operating system had no safeguards against such mistakes, sealing the spacecraft’s fate.

Likewise, when the scientifically potent Japanese Hitomi X-ray satellite was spinning out of control in Earth orbit in 2016, a wrong, previously uploaded command fired its thrusters in a way that accelerated Hitomi further instead of slowing it down. The spacecraft broke apart into over ten pieces.

A rocket self destructs because it thinks it’s going too fast

On June 4, 1996, Europe’s then new heavy-lift Ariane 5 rocket launched successfully. Merely 37 seconds into the flight, the rocket flipped 90 degrees, and the onboard computer triggered the self-destruct mechanism just two seconds later. Pieces of the expensive rocket and the four science satellites onboard slammed into the ground, which people on a nearby beach could see!

The Ariane 5 rocket was brand new but it was still running some code from its predecessor Ariane 4. The investigation results revealed that some of that old code wasn’t properly adapted for the more powerful Ariane 5. Just before the rocket flipped, it attempted as usual to convert its sideways velocity from a 64-bit “floating point” format to 16-bit “signed integer” format. The resulting latter number at that point was too large for the computer to store or act on. The flip caused the rocket’s two solid boosters to swing out and nearly detach from the body, which triggered the self-destruct.

Usually, such conversion errors are protected by detection and recovery mechanisms in the code, and indeed such protections were present on the Ariane 5’s computer as well. However, in this particular case, the engineers had decided the specific velocity in question was too high to become a real problem. That was only true for the Ariane 4.

An imperial spacecraft destroyed on Mars

The loss of NASA’s Mars Climate Orbiter is a human error on an organizational scale like none other. The spacecraft launched successfully in 1998 and cruised to Mars until September next year just fine. After nearing the red planet, it was supposed to brake and enter orbit. But the spacecraft’s trajectory took it too close to Mars and it disintegrated in the upper atmosphere.

It was later realized that the two mission engineering teams communicating with each other had been using different units for their calculations. The mission navigation team was using metric units, as expected, but the spacecraft manufacturer Lockheed Martin sent commands in conventional imperial units. The seemingly trivial mismatch of converted values obliterated the spacecraft and its $300 million dollars ($500 million in 2021).

A similar case of using different unit conversions almost resulted in NASA and ESA losing their SOHO solar observatory, a now thankfully highly successful mission.

Dropping a satellite on the floor

Another equally embarrassing mistake was when Lockheed Martin workers dropped NASA’s NOAA-N' Earth observation satellite on the floor in 2003. The NASA investigation report revealed that during a standard test, a technician had removed 24 bolts that helped hold the spacecraft in place but failed to document it. A team that came later was moving the spacecraft from vertical to horizontal position for another test but failed to check if all bolts were in place, as was specified in the procedure. The spacecraft fell on the floor and was badly damaged.

Lockheed Martin agreed to forfeit all profit from the project and paid $30 million for repairs. However, the total repair cost was $135 million, the difference of which was paid by the U.S. government.

A hard landing for Genesis

Sample collection missions are hard but NASA’s Genesis spacecraft launched in 2001 had already successfully collected samples of the solar wind and was about to bring them to Earth in 2004. When the sample-carrying probe was descending in Earth’s atmosphere, its parachute never deployed. It crashed into the Utah desert. Many of its sample collectors shattered upon impact, and some remaining samples were  contaminated by the desert air. Scientists worked hard to safely recover the remaining intact samples for study but the mission’s science output was of course lower than expected.

NASA’s failure report in 2009 revealed that Lockheed Martin, the spacecraft manufacturer, had incorrectly installed the probe’s accelerometers in inverted position, which led the spacecraft to think it was going up rather than down!

A similar assembly mistake of installing inverted cables on the European Vega rocket moved the upper stage engine nozzles in the wrong direction during a 2020 flight. This misled the upper stage’s guidance system and so it couldn’t orient itself. The upper stage tumbled and failed to reach desired orbit, losing the satellites onboard.

As we embark on increasingly technologically complex space endeavors such as sustainably living on the Moon, exploring the outer solar system moons, bringing samples from Mars, and more, the increased functionality demanded by such missions could inevitably make human errors likelier.

The general industry direction of late has thus been to reduce human errors by reliably automating as many parts of missions as possible, taking advantage of modern software. This is especially true for mission operations, a major element still heavily reliant on humans to be in the loop. So when humans are exploring the Moon again, the mission control center would look and operate very differently.

Thank you Epsilon3 for supporting me, which allowed me to work on this article. The article’s theme has been inspired by my other piece, “Space grade electronics: How NASA Juno survives near Jupiter

<Intro from the supporter> Epsilon3 is a web-based platform for managing complex spacecraft operational procedures that provides coordination, assurance, and risk reduction to prevent failures like some of the ones mentioned here and more.

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<![CDATA[Experiments at the International Space Station that paved the way to living on Mars and beyond]]>https://blog.jatan.space/p/iss-experiments-living-on-mars-and-beyondhttps://blog.jatan.space/p/iss-experiments-living-on-mars-and-beyondFri, 02 Jul 2021 10:04:00 GMTNASA wants to send humans to Mars in the 2030s, while the ever-optimistic Elon Musk hopes for its SpaceX Starship to carry crews to the red planet much earlier. After landing humans on the Moon again in this decade thanks to NASA’s Artemis ambitions, Mars is the next giant leap. And we’ve been preparing for that moment right here, in Earth orbit.

For over two decades, there’s been a giant space laboratory speeding around Earth. Larger than a Boeing 747 airplane, the International Space Station (ISS) is the largest human spacecraft ever built.

The International Space Station as photographed by a crew member onboard the Space Shuttle Atlantis. Credit: NASA

Since the launch of its first two modules in 1998, the ISS has been significantly expanded in size and function. It now boasts over a dozen unique modules built by a total of five collaborating space agencies. All this time the ISS has sustained human presence, hosting over 200 astronauts in total. Rockets have been launched every few months to send supplies in the form of food, equipment and tools, and experiments. With the ISS, we have successfully built and operated a long-term human habitat in space.

Notably, the ISS has provided a stable environment for human researchers to carry out long-term space experiments. This ability has been critical for researchers looking to solve the problems of zero gravity habitation. Here are some experiments on the ISS that have contributed toward enabling our Mars ambitions.

Keeping fit on your interplanetary cruise

With chemical rockets, a trip to Mars takes at least six months. Future astronauts are in for a lengthy interplanetary cruise in a zero gravity environment. By having astronauts stay on the ISS for months and even a year, researchers have been able to study the effects of prolonged space exposure and reduced gravity environments on the human body, and devise methods to keep astronauts healthy.

A 2006 study found that long term exposure to microgravity environments caused considerable bone and muscle loss in ISS astronauts. Future astronauts would have trouble moving after landing on Mars and would be prone to fractures. To prevent muscle loss, astronauts on board the ISS exercise for hours everyday. But humans sweat more during exercise when in orbit—this may seem like a minor thing, but it’s not. The lack of convection in space means that heat envelops astronauts’ bodies like an aura, and sweat stays where it originated due to lack of gravity. Such a warm and humid environment is an ideal entry point for bacterial infection.

To remedy this, the Europe-led SpaceTex experiment produces special fiber clothing that astronauts wear during exercise. Its materials dissipate heat effectively and reduce microbiological contamination while keeping astronauts comfy. All necessary for a long trip to Mars and beyond.

ESA astronaut Alexander Gerst on the International Space Station’s fitness bike wearing SpaceTex clothing. Credit: ESA

A more recent study of 11 ISS astronauts on six-month missions revealed that more than half of them experienced stagnated blood flow. One astronaut developed a blood clot and needed to be treated with anticoagulants for the rest of the spaceflight.

To prevent blood clots, the ISS has a “Chibis suit” in one of the Russian modules. These vacuum-sealed pants lower pressure below the waist to ensure adequate blood flow in upper parts of the body. The Chibis suit is a promising solution for preventing blood clots in astronauts on long interplanetary flights.

Russian Cosmonaut Yuri Malenchenko wears the Chibis suit. Credit: Roscosmos

On the Moon, Mars, asteroids, and comets, astronauts’ lungs may become easily irritated or inflamed by dust particles. The reduced gravity on such celestial bodies makes floating dust a real threat for humans. To solve this, The European Space Agency (ESA) has been leading a study to monitor astronauts’ lungs for over 10 years.

The ISS astronauts breathe into a specially developed instrument to measures nitric oxide levels, an indicator of lung inflammation. These measurements are taken at reduced pressures in an airlock to simulate conditions in future Moon and Mars habitats. This information is helping researchers devise ways to ensure the health and safety of astronauts on landing missions beyond Earth.

The ISS is also a lab for studying changes in plants and microorganisms from long-term space exposure. Healthy habitats for plants and microbes on other worlds are an assumed requirement, because they are crucial for food and ecosystems.

Growing food on Mars

Most of us were amused when Mark Watney, in the film The Martian, grew potatoes on Mars with his own feces as fertilizer. The ISS hasn’t gone exactly that route with their fertilizers, just yet, but learning to grow our own food on Mars is a serious necessity.

Enter Tomatosphere, a joint Canadian and U.S. experiment. Since 2001, millions of tomato seeds have been flying to the ISS over multiple missions. These seeds are exposed to space radiation for several months, and then brought back and planted on Earth to see if—and how—they grow differently from regular tomatoes. Space-exposed tomato seeds show clear differences in how they germinate, from how fast they grow to visual changes in the size and color of their leaves. But other than that, you can just as easily consume them.

Canadian astronaut Chris Hadfield poses with 600,000 tomato seeds from the Tomatosphere project, which returned to Earth with Hadfield in May 2013 after orbiting Earth for nine months onboard the ISS. Credit: NASA

A long-term mission to Mars can’t carry all the food required for the trip. Even if they could, counting on timely supplies is a good backup strategy at best. The crew will need to produce their own food. By teaching us how to grow plants effectively in a radiation-filled environment, Tomatosphere and other such ISS experiments are enabling an interplanetary future.

Microbes on the red planet

ESA leads a series of experiments on the ISS under the EXPOSE program. In each such experiment, microorganisms like bacteria, lichens, fungi, and algae are placed in containers outside the ISS, where they are exposed to the harsh conditions of space. Some of these containers mimic martian conditions with simulated martian soil, an artificial atmosphere, and controlled radiation conditions.

An EXPOSE module strapped outside the ISS, exposing microorganisms to the harsh radiation in space. Credit: ESA / Roscosmos
Simulated martian soil in containers, part of EXPOSE modules strapped outside the International Space Station. Credit: DLR

The longest of these experiments exposed microbes for 533 days. In the end, some microbes of every species survived. To everyone’s surprise, some lichens survived too, despite being more complex life forms. Thanks to EXPOSE, we now know that many microorganisms can be considered for use in initial habitats on Mars.

Powering a Mars mission

Another martian challenge the ISS is helping solve is computing. You see, space computers are not as capable as ones on Earth, as they need to be hardened to work reliably in the harsh space environment. Engineers sometime work around this by offloading intense computing tasks to computers on Earth, much like the Apollo missions. This works well for human missions to the Moon where the communication lag is but a few seconds. But a 10-20 minute signal lag for Mars is simply not feasible.

So engineers have been testing powerful supercomputers on the ISS, built to withstand more space radiation. In 2017, a SpaceX cargo supply mission to the ISS brought one such supercomputer by NASA dubbed Spaceborne. During its mission, Spaceborne successfully performed over a trillion calculations per second for 207 days straight without requiring a single reset. This timescale is promising for Mars missions.

A Spaceborne Computer prototype in an ISS mockup on Earth. Credit: HPE

Another such computer SG-100 was tested for two years with zero resets. SG-100 processes data 12 times faster than a standard ISS computer, and costs a quarter the price. These tests are proving the capabilities of powerful computers for interplanetary missions, removing the need to downlink all data to Earth in many cases.

“In low-Earth orbit, we are able to shrink the data down to a minimal set before you send it down,” said Trent Martin, primary investigator for SG-100. He added, “In deep space, it allows you to actually do your processing there. Now, if we are doing the processing on Mars, rather than taking the time to send it back to Earth and then back to Mars—that is 16 minutes that’s just eliminated.”

Fueling a mission to Mars and beyond

One of the most critical problems for sustained human presence in the solar system is fuel. For instance, a trip to Mars and back would require at least 10-20 times more fuel than Apollo 11, depending on mission specifics. Dragging all that fuel out of Earth’s deep gravity well wouldn’t just be inefficient—but incredibly expensive and non-sustainable.

To solve this problem, NASA has been testing advanced cryogenic fuel storage and transfer technologies on the ISS. With this technology in place, spacecraft landing on the Moon and Mars can be refueled to either return to Earth, or venture farther out. Note that this is precisely what Elon Musk hopes to do with Starship at Mars.

NASA launched three experiments to the ISS under the banner of Robotic Refueling Missions. The first two of these demonstrated preparation tasks that lead up to cryogenic fuel transfer in orbit, such as removing caps and valves, installing coolant line adapters, etc. To perform these tasks, a suite of tools at ISS were used, including the two Canadian robotic arms and the servicing robot Dextre.

Robotic Refueling Mission 3 Fluid Transfer Module. Credit: NASA

One major issue with cryogenic fuel however is that it quickly boils off to space, making it impossible to use for Mars missions. For this, the third of the Robotic Refueling Missions was launched in December 2018 to the ISS. Unlike traditional methods that use passive cooling, it used active cooling and advanced multi-layer insulation to prevent fast boil off. In all, it demonstrated storage of cryogenic fuel for four months in orbit, a promising progress towards usage in interplanetary trips.

These are just some highlights from the hundreds of experiments at the International Space Station that have directly laid a foundation for living and working on Mars and beyond. Even as the station’s future remains unclear, it worth remembering that the ISS has been a spectacular example of global cooperation for almost 3 decades despite political conditions. Alexey Krasnov, head of human space flight program for the Russian space agency wrote the following in 2011.

When compared with partners acting separately, partners developing complementary abilities and resources could give us much more assurance of the success and safety of space exploration. The ISS is helping further advance near-Earth space exploration and realization of prospective programs of research and exploration of the Solar system, including the Moon and Mars.

Originally published at Supercluster.


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<![CDATA[Space grade electronics: How NASA Juno survives near Jupiter]]>https://blog.jatan.space/p/space-grade-electronicshttps://blog.jatan.space/p/space-grade-electronicsFri, 18 Jun 2021 11:22:00 GMTNovember of 2011 was a particularly exciting time for planetary scientists. Russia had launched its Phobos-Grunt spacecraft to land on Mars’ moon Phobos, the first ever such attempt. The spacecraft was to return 200 grams of samples from Phobos, to help determine the origin of the martian moons as well as fill important gaps in our understanding of the history of the solar system.

The launch was successful but the spacecraft failed to fire its engines and thus never left Earth orbit. Its orbit decayed in a matter of weeks. Pulled by the Earth, it plunged into the ocean, resulting in a total mission failure. Along with the spacecraft, China’s first Mars orbiter Yinghuo-1 and The Planetary Society’s LIFE experiment onboard were lost too.

So what went wrong? The failure report revealed that the spacecraft’s electronic components were neither qualified to be used in space nor tested prior to launch. The loss of Phobos-Grunt and the science it could do was a bitter reminder of the unforgiving nature of space exploration. Cutting corners in spacecraft development and testing to save some costs can end up costing us even more. In this article, I take a look at how electronics of spacecraft are built to survive space environments and examples of its failures and successes in notable space missions.

Making electronics space-ready

Electronic components used in spacecraft must be built to survive and function in harsh space environments. The U.S. Department of Defense mandates over 100 tests to ensure reliable operation of components under mechanical stress, wide temperature fluctuations, and the intense radiation of space. All space grade electronic components must be individually qualified as opposed to batch testing common in commercial or industrial applications.

Illustration of a NASA Voyager spacecraft. Both the Voyagers, launched in 1977, are still functioning. Credit: NASA

To ensure the desired reliability in space, system designers can’t use the latest and greatest computer hardware in space missions. If we take a look at CPUs used in spacecraft, we find that most of them are very old, some even dating back to the 1990s. It’s critical to use something that has been tried and tested, that we know will work. Electronic components are hardened for space usage using some of the following techniques:

  • Filling electronic assemblies with a solid/gelatinous compound that can resist the shock and vibration of a rocket launch, the latter of which is no joke.

  • Using an insulating material as a substrate instead of silicon used in commercial electronics to reduce stray currents.

  • Static RAMs (SRAM) instead of Dynamic ones (DRAM) because they are less power hungry, crucial for when spacecraft enter low-power modes but need to continue sending telemetry.

  • An external shield, like lead, around the electronic components to reduce exposure to radiation, thereby increasing the mission’s life span. This is particularly useful for long-term missions like New Horizons which is currently exploring the Kuiper Belt.

As a result of these techniques, the sizes of electronic components qualified for space usage are usually much larger than commercial or industrial ones.

Even with all of these modifications to prepare electronics for space, intense radiation can still cause numerous issues such as memory losses, short circuits, and irreversible damages to the circuitry. Spacecraft electronics and its logic must thus be built with all of these factors in mind.

Apart from the Phobos-Grunt incident, let’s take a look at space missions which act as a constant reminder of the harsh nature of space. This part of the article is inspired by Emily Lakdawalla’s piece on sample collection.

Notable electronics failures in space missions

1. When you lose your star sensors

India’s first Moon orbiter Chandrayaan 1’s star sensor failed after a few months in lunar orbit. The extreme exposure to solar radiation caused the backup star sensor to fail too.

The rest of the mission had to be completed using onboard gyroscopes and constant corrections sent from Earth via ground stations. The mission was ultimately successful but it was a reminder that even space grade components can falter.

2. When you have six computers to do one job

The Galileo spacecraft designed to orbit and study Jupiter had not one but six CPUs. Surviving in the radiation riddled Jovian environment—which is orders of magnitude more intense than Earth’s—mandated that each major subsystem of the spacecraft be controlled by its own CPU. That way if one CPU dies, it only disables one major instrument.

Schematic of Jupiter’s magnetosphere encompassing its four Moons. The Galileo spacecraft faced intense radiation on all close passes to Jupiter. Credit: John Spencer

The Galileo spacecraft’s computing system was equivalent in processing power to the classic Apple II computers sold a decade prior. Each of Galileo’s CPUs were fabricated on an insulating sapphire material, hardened for the intense radiation at Jupiter. Despite these protective measures, Jupiter’s harsh environment caused more than a dozen issues to the Galileo spacecraft over time, including frequent resets of all of its computers.

3. When solar flares damage your solar panels

En route to the asteroid Itokawa in 2003, the Japanese spacecraft Hayabusa was hit by one of the largest solar flares in recorded history. The flare damaged Hayabusa’s solar panels, thereby reducing their capacity to deliver power. The flare also caused one of the four ion engines on the spacecraft to stop functioning. These degradations reduced the mission’s duration and scope.

JAXA’s Hayabusa spacecraft at Itokawa. Credit: JAXA

Excessive radiation damaging solar panels was a serious concern when designing Juno, NASA’s spacecraft currently orbiting Jupiter. Juno engineers knew the solar panels would degrade with time at Jupiter so they designed the solar panel glass to be twice as thick than usual, and increased the panel size. This means that even as radiation at Jupiter degrades the panels continually, Juno would still have sufficient power for years after reaching Jupiter.

4. RAD computers

One of the latest generations of radiation-hardened processors, in space grade terms, is the 32-bit RAD750, based on the PowerPC 750 designed by IBM. It’s designed to minimize damage even when facing extreme radiation from solar flares. Capable of working in a wider temperature range and boasting 10 times better performance than the previous generation RAD6000, the $200,000-costing RAD750 has been used in over 150 space missions, including everyone’s favorite Mars rovers Curiosity and Perseverance.

Radiation tolerant Curiosity rover near Mount Sharp on Mars. Credit: NASA

The Curiosity rover has two RAD750 CPUs for redundancy. When the first one faced issues with its flash storage in 2013, the backup computer took over.

The case of Juno and Jupiter

Designed to study Jupiter from closer to the planet than any spacecraft before it, Juno is faced with unique challenges. For Juno, having individually tested space grade components, one of the most radiation-hardened CPUs, and redundant components is all still not enough to face the harsh environment near Jupiter, the planet with the largest magnetic field in the solar system.

Juno’s orbit takes it extremely close to Jupiter to achieve its science objectives, exposing it to hazardous radiation belts in Jupiter’s magnetic field in the process. Credit: NASA

A RAD750 CPU can withstand up to 1 million rads of radiation exposure by itself, which is remarkable. But the mission would expose Juno’s components to at least 20 million rads over time. That’s quite intense. To protect the electronic components, the engineers built a protective titanium armor shield with centimeter-thick sides. This cubical vault reduces the radiation exposure to the electronic components by 800 times. The shield is so important to Juno’s functioning that it gets its own reassuring name—Juno Radiation Vault.

NASA JPL engineers installing the Juno Radiation Vault designed to protect its electronic components at Jupiter. Credit: NASA

Without its protective radiation vault, Juno’s brain would get fried on the very first pass near Jupiter.

Scott Bolton, Juno’s Principal Investigator

Even then, Juno is expected to cease functioning eventually due to its multiple close passes to Jupiter, deep into the planet’s dangerous radiation belts. A reminder that space is hard.

But it’s worth exploring.

Originally published in 2018, updated for 2021. Republished by The Planetary Society.


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<![CDATA[How NASA decides where to land on Mars]]>https://blog.jatan.space/p/how-nasa-choses-mars-landing-siteshttps://blog.jatan.space/p/how-nasa-choses-mars-landing-sitesThu, 20 May 2021 10:30:47 GMTNASA’s successful touchdown of its $2.7 billion Perseverance rover in Mars’ Jezero crater on February 18 is a triumphant culmination of four decades of increasingly challenging landings on the Red Planet. The now dried-up river delta and lakebed of Jezero is so ideal to sniff out signs of fossilized creatures from the planet’s warmer, wetter, more habitable past, one might wonder why NASA’s number of prior missions never visited here. The answer is simple: Attempting a landing in such complex terrain has been impossible until now.

When we begun exploring Mars with robots in the 1970s, the best available pictures of the planet’s surface were so crude that targeting where to land was akin to playing a blindfolded game of darts. NASA’s first landing efforts, the Viking 1 and 2 missions of 1976, had to snap images from orbit before mission planners could pick landing sites, and even then any semblance of safety was far from guaranteed. The vintage tech at the time could only ensure that each lander would come to rest somewhere within an ellipse 300 kilometers long and 100 kilometers wide, hopefully close to a central point scientists had flagged for investigation. Ultimately, NASA officials put this “landing ellipse” on the safest places they could see from orbit, setting down each Viking in a smooth, near-featureless plain stretching more than a thousand kilometers.

Shrinking the ellipse

By the time Spirit and Opportunity, NASA’s twin Mars Exploration Rovers (MERs), were to land in 2004, the space agency’s engineers had learned how to shrink the ellipse to 150-by-20 kilometers. This tenfold improvement over the Vikings was possible thanks to better understanding of Mars’ atmosphere as well as new techniques for spacecraft navigation. By this time, NASA also had much better map and mineralogy data from its orbiters. Scientists used that information to have Opportunity target a region where there was hematite, a mineral that only forms in the presence of water, as a way to study an ancient, alien watery environment.

“Combining landforms and mineralogy data of a region, and taking advantage of engineering upgrades, Opportunity was the window into the future of how we choose landing sites,” says Briony Horgan, a co-investigator on the Perseverance mission.

NASA had considered landing the MER missions in a much richer site, Gale Crater, where the agency’s Curiosity rover ultimately landed in 2012 and still operates today. But the crater’s central mountain––near which Curiosity found evidence for ancient, microbe-friendly freshwater lakes––was itself a landing hazard for the MERs. The skinny landing ellipses of MERs were as long as the crater itself, posing a real risk of the multi-hundred-million-dollar rovers slamming into the mountain or crater walls during their descent. So NASA engineers gave their successor, Curiosity, the ability to steer to compensate for large deviations that could be caused by wind, shrinking the landing ellipse to an impressive 20-by-7 kilometers.

 The landing ellipses shown here on top of Gale crater on Mars illustrate the accuracy of Curiosity’s guidance system compared to that of earlier missions, including Spirit and Opportunity. Credit: NASA / JPL-Caltech

Thanks to its nuclear power supply, Curiosity could also drive much longer distances than the MERs, and had a mission life span of years as opposed to a few months. This was critical to Gale’s selection as Curiosity’s landing site since engineers could now drive the rover to the mountain after a safe landing away from it. “Even if a MER rover had safely landed inside Gale, not only would the mission have been much different but neither of them could’ve gone to the mountain,” says Melissa Rice, a collaborator on MERs, and a co-investigator for the Mastcam-Z camera on Perseverance.

Nestling into Jezero

For Perseverance, Curiosity’s previous success allowed far more landing sites to be considered. NASA’s latest rover is a near-clone of Curiosity and used the same stunning “sky crane” method for its touchdown. Data from Curiosity’s Entry, Descent and Landing (EDL) helped engineers reduce Perseverance’s landing ellipse by about 50 percent, says Chloe Sackier, an EDL systems engineer for Perseverance. “While EDL for Perseverance looks similar to Curiosity, it’s a lot smarter on the inside,” she says. “We have a new technology called Range Trigger to deploy the supersonic parachute based on where the spacecraft thinks it is, as opposed to deploying at a predetermined velocity, which led to Curiosity flying slightly longer in the Martian atmosphere.”

After prior missions painted the picture of a watery, habitable early Mars, NASA wanted Perseverance to actively seek signs of past life. Mission planners had much more satellite data to play with too. “Some sites that were first proposed for Curiosity became serious contenders for Perseverance’s selection after the Mars Reconnaissance Orbiter revealed more about the minerals and rock types at those sites,” Rice says.

Armed with high-resolution imagery as good as 30 centimeters per pixel and detailed mineral maps, more than 150 scientists carefully examined in excess of 60 promising locations, filtering them over five years and ranking the best ones. In the 2017 grand finale filter of this habitability- and geology-flexing competition, 3 sites rose to the top.

Although all three sites represented potentially habitable ancient locales, Jezero won out because its lake-delta system uniquely offered multiple, distinct opportunities to probe for signs of past life. “Jezero might be most well-preserved ancient delta, representing the most habitable period in Mars history when we see evidence for rivers flowing all over the planet’s southern hemisphere,” Horgan says.

However, Jezero’s delta could not be efficiently targeted even with the improvements made on Curiosity’s landing ellipse. The delta’s most promising feature––its sprawling, sediment-rich base––was a landing hazard due to adjacent tall, wide cliffs. At best, Perseverance could land east of the delta and spend months driving to the base.

At least that was the case until 2019, when NASA revealed that Perseverance would use a new technology called “Terrain Relative Navigation (TRN)”. Instead of descending on Mars with a blind eye, a spacecraft with TRN can look at terrain features below it and compare it to preloaded maps to know where it is, allowing it to autonomously and flexibly guide itself to a more pinpoint landing. With these advances, the Perseverance landing ellipse was now a solid 7.7-by-6.6 kilometers.

The introduction of TRN completely changed the game for scientists. “TRN allowed nestling into landing areas almost anywhere we wanted,” Rice says. “Landing right at or near the preserved Jezero delta base, where the rivers deposited concentrated organic material, was possible. TRN made the mission land-on rather than go-to.”

“We historically had to look for large, smooth ‘parking lots’ for landing things on Mars,” Sackier says. “We could now open up sites like Jezero due mostly to the inclusion of TRN, which allowed us to target multiple little parking lots within the landing ellipse instead of a giant one.”

Left: Mineralogy data from NASA’s Mars Reconnaissance Orbiter overlaid on top of its Jezero Crater image. The green near the crater rim indicates the presence of carbonates, marking especially promising places to search for signs of past life. Right: A possible route for Perseverance rover across Jezero Crater as it investigates several ancient habitable environments, starting from the base of the river delta to carbonate deposits near the crater rim. Credits: NASA / JPL-Caltech

Sure enough, Perseverance’s landing system performed remarkably well on February 18, 2021 as it landed the rover in a smooth little parking lot within an otherwise rough terrain just 1.7 kilometers away from the center of the landing ellipse. Perseverance will spend the next 2-3 years traveling across the delta’s dry riverbeds to the edge of Jezero crater, searching for various biosignatures. It will gather and store samples of its most promising finds, depositing some of them for eventual retrieval by a ‘fetch rover’ from the joint NASA-ESA sample return mission launching no earlier than 2026. Engineers will use data from Perseverance’s EDL to further tighten the landing ellipse for the fetch rover, hopefully shrinking the distance it needs to travel across the planet’s surface.

Where to next?

Even with these impressive advances, some sites on Mars are still out of reach for spacecraft landings and will likely remain so for the foreseeable future. For instance, scientists cannot propose landing on high-altitude features such as Olympus Mons because the atmosphere overhead is too tenuous to sufficiently slow down a spacecraft. Regions with very rough terrain or steep slopes are also off-limits, even with TRN. Furthermore, features such as polar ice caps, canyons, lava tubes and sand dunes offer poor prospects for wheeled rovers, demanding alternate forms of mobility.

Nevertheless, the precision landing technologies NASA has developed for Mars over decades will enable exploring uncharted places in the solar system. “TRN, for instance, can enable landing a spacecraft on Jupiter’s moon Europa while avoiding its huge icy cliffs, boulders, and other obstacles,” Rice says.

The payoff of NASA’s Mars program is not just technical. “We learned how to efficiently operate a spacecraft on another planet for long periods of time. We give Curiosity commands three to four days in advance and it semiautonomously completes them. That experience is enabling ambitious things at the Moon, like having the upcoming VIPER rover, launching in 2023, largely autonomously explore permanently shadowed regions on the lunar poles,” Horgan says.

TRN will also enable NASA’s Artemis robotic and crewed missions to perform precision landings on the Moon’s south pole, which lacks large, flat areas. Moonbases in the future would also benefit from TRN as robotic cargo missions would only need to drive short distances post-landing.

Thanks to NASA’s ambitious, multi-decade Mars endeavors, a new era of pinpoint landings throughout the solar system may be underway.

Originally published at Scientific American.


<![CDATA[Can we make Mars Earth-like?]]>https://blog.jatan.space/p/can-we-make-mars-earth-likehttps://blog.jatan.space/p/can-we-make-mars-earth-likeFri, 23 Apr 2021 12:01:50 GMT
This artist's concept shows what Mars might look like if it were terraformed to host Earth-like conditions. Credit: Alamy images

Mars was once an Earth-like world.

When life emerged on our watery planet sometime between 3.5 to 4 billion years ago, Mars was also home to lakes of liquid water and possibly flowing rivers. Combined with a thick atmosphere, a magnetic field to shield against radiation, and a variety of organic molecules, Mars had favorable conditions to form and support life as we know it.

Mars probably didn’t remain habitable for very long, though. The Red Planet lost its magnetic field sometime between 3 to 4 billion years ago, which allowed the solar wind––an incessant stream of energetic particles coming from the Sun––to strike and strip away most of the planet’s atmosphere and surface water, turning Mars into the chilly desert we see today.

Can we reverse nature’s effects and terraform Mars into a habitable planet again? Here’s what it could take:

Warming up the Red Planet

Mars’ atmosphere is far too thin and cold to support liquid water on its surface. With an atmospheric pressure just 0.6% of Earth’s, any surface water would quickly evaporate or freeze, just as NASA’s Phoenix lander saw in 2008

There are a few different schools of thought on how—or if—we could heat up Mars’ atmosphere and make it more hospitable to life. Elon Musk has suggested, for example, that we could terraform Mars by exploding nuclear bombs over its polar caps. He says that the radiation wouldn’t be an issue since the explosion would be in space over the poles, but the heat release would vaporize the frozen carbon dioxide to greenhouse warm the planet and melt the water ice.

Nuking Mars raises a host of scientific, ethical, and legal questions. From a scientific perspective, researchers estimate that the resulting melted water ice could easily cover the planet to a depth of a few tens of meters, but it probably wouldn’t last for long. The carbon dioxide added to Mars’ atmosphere by vaporizing the polar caps would only double the pressure, a far cry from the comparable pressure to Earth required for conditions warm enough to sustain surface liquid water and atmospheric water vapor.

Mars has more abundant sources of carbon dioxide, such as those locked in the martial soil and tightly bonded carbon in minerals. But based on 20 years of NASA and ESA satellite data, researchers estimate that even if we mine Mars’ entire surface for carbon dioxide, the atmospheric pressure would still only be about 10-14% of Earth’s. This would correspond to an average temperature rise of about 10 degrees Celsius––not nearly enough to sustain liquid water.

To put this all into perspective: we would need more carbon dioxide to meaningfully warm up Mars than humans have released throughout our entire history on Earth. Terraforming Mars is therefore a daunting endeavor that doesn’t seem possible with current technology.

With future technological advances, we might be able to excavate minerals deep in the Martian crust that may hold significantly more carbon dioxide and water. But the extent of these buried deposits isn’t currently known or evidenced by satellite data. We could also artificially introduce heat-trapping gases that are superior to carbon dioxide, like chlorofluorocarbons. These gases are short-lived, though, so the process would need to be repeated on a large scale to keep Mars warm.

Another idea is to import gases by redirecting comets and asteroids to hit Mars. However, this isn’t exactly practical, as it would require an inordinate amount of impacts to make any meaningful difference.

Breathing on Mars

Another challenge is making Mars’ atmosphere breathable. The MOXIE experiment on NASA’s Perseverance rover recently converted carbon dioxide from Mars’ atmosphere into oxygen. Future human explorers could use this kind of technology to generate oxygen for their habitats. However, doing this for the entire planet may not be feasible. This is why some researchers suggest turning to forms of life that have already transformed Earth’s atmosphere.

On Earth, cyanobacteria were responsible for converting, via photosynthesis, our atmosphere of methane, ammonia and other gases around 2.5 billion years ago into the oxygen-rich one of today. Since Mars receives less than half the sunlight as Earth—and has a global dust storm problem that makes visibility worse—researchers have suggested that we introduce special microorganisms on Mars that photosynthesize in low-light to create breathable air for humans. When paired with other organisms, an entire life cycle could be created on Mars with a favorable blend of gases.

On the International Space Station, researchers regularly test the ability of microorganisms to withstand non-Earth environments. In one such test, some microorganisms survived in a container with Mars-like conditions for 533 days, including some lichens, despite them being more complex life forms.

The main challenge of a microorganism-induced breathable Mars is time. NASA conducted a feasibility study in 1976 that concluded it would take at least a few thousand years for even extremophile organisms specifically adapted for the Martian environment to make a habitable atmosphere out of the Red Planet. The agency has since studied using microorganisms to produce oxygen for future human explorers. 

Fixing the Achilles heel

Even if we somehow managed to introduce enough carbon dioxide and oxygen in the Martian atmosphere—and sustained liquid water on the surface––the resulting Earth-like conditions would probably be short-lived.

NASA’s MAVEN mission has revealed that Mars is losing its atmosphere even today. The planet’s lack of a protective magnetic field means the solar wind will continue stripping its atmosphere and water, reverting our changes to Mars or constantly degrading them.

To truly terraform Mars, we would need to fix its magnetic field—or lack thereof. While we don’t have the technology to churn the core of a planet faster to revive its magnetic field, NASA’s Chief Scientist Dr. Jim Green and his colleagues have theorized that a magnetic field placed at point called L1 between the Sun and Mars, where their gravities roughly cancel out, could in theory encompass Mars and protect it from the solar wind.

A simulation snapshot showing how a sufficiently strong magnetic field placed at the Sun-Mars L1 point could protect Mars from the atmosphere-stripping effects of the solar wind. Credit: Dr. Jim Green, NASA

After conducting extensive simulations which incorporated existing spacecraft data about solar wind behavior and the Martian atmosphere, Green and team say a magnetic field of 10,000 to 20,000 Gauss would sufficiently shield Mars against the solar wind. Green acknowledged that the idea sounds “fanciful” but noted that we can currently put a field of about 2,000 Gauss at the Sun-Mars L1 point. Undertaking such an endeavor is therefore not possible today, but technological advances in the coming decades could make it plausible.

If we stopped or limited Mars’ atmospheric loss, we could hypothetically pursue a number of warming methods. Over the next hundreds of years, we could restore as much as 1/7th the amount of liquid water as Mars once had in its oceans, and bring back some aspects of that period of habitability.

Even then, since Mars has 38% of Earth’s gravity, it can only retain an atmosphere of about 0.38 bar. In other words, even a terraformed Mars would be very cold by Earth standards and its air about as thin and chilly as the Himalayan mountains.

In short, it seems very improbable that we could transform Mars into a more Earth-like planet. In the meantime, NASA’s multi-decade Mars program seeks to understand the planet’s suitability to host past or present life. Near-term Martian explorers would likely live in enclosed structures on the surface or subsurface, built using material from the Red Planet. For now, would-be terraformers will have to humbly hone their ideas on how to transform Mars into an open world.

Originally published at The Planetary Society.


<![CDATA[Daring gravity assist maneuvers in space]]>https://blog.jatan.space/p/daring-gravity-assist-maneuvershttps://blog.jatan.space/p/daring-gravity-assist-maneuversWed, 14 Apr 2021 11:25:00 GMTTraveling the vast distances of space isn’t cheap for a spacecraft. It costs time, fuel and money. Fortunately, nature offers free help along the way which mission designers are happy to take. Enter gravity assists.

In these maneuvers, a spacecraft exchanges momentum in a close encounter with a planet to gain or reduce velocity, as required for the mission. This saves time and cost, or even makes up for lack of technological abilities at times. If you want to know how gravity assists work, my explainer article has real mission examples, including how the twin Voyager spacecraft used Jupiter to be on a trajectory out of the solar system.

Gravity assists are regularly used in numerous interplanetary missions to propel spacecraft towards their destinations. This article takes a look at some of the lesser talked about gravity assists used by past space missions.

Studying the Sun from above

In 1990, NASA and ESA launched a joint mission called Ulysses to get the first ever look at our Sun’s poles. For that, the spacecraft would have to go out of the plane in which planets go around the Sun so it can look over the Sun.

Artist’s impression of the Ulysses spacecraft looking over at the Sun’s poles. Credit: NASA JPL

The only problem? No rocket in existence was, or is, capable of putting a spacecraft in an orbit with the required high inclination. The solution lay in the solar system’s most massive planet—Jupiter.

Much like how a close encounter with a planet can change a spacecraft’s velocity, as in the case of Voyagers, it can also change the spacecraft’s inclination. In 1992, mission operators has Ulysses pass closely over Jupiter’s north pole and the planet’s intense gravity bent the spacecraft’s trajectory southward. This put Ulysses in a solar orbit that would take it past the Sun’s north and south poles at an inclination of 80° compared to the orbital plane of the planets.

Visual showing in orange the plane in which the planets of the solar system orbit the Sun. The Ulysses spacecraft achieved a first-of-a-kind polar orbit around the Sun with the help of Jupiter’s gravity. Credit: tes teach

While Ulysses didn’t see the Sun’s poles like our eyes would because it lacked an optical camera, it did have other instruments which took various scientific measurements for 18 years. A standout discovery by Ulysses was that the Sun’s south pole is colder than its north pole. Ulysses also gave us first direct measurements of interstellar dust particles and helium atoms in the solar system. The spacecraft also unexpectedly found itself in gaseous tails of comets every now and then, achieving bonus science points.

The comet chaser’s “Billion Euro gamble”

ESA’s Rosetta spacecraft—the first to orbit a comet—extensively studied and monitored the elegant two-lobed comet named 67P. However, getting to comet 67P in the first place was an ordeal.

To rendezvous with the comet, Rosetta had to match its velocity. This was achieved using gravity assists around multiple solar system objects over 10 years.

One of those maneuvers involved a low-altitude Mars flyby in 2007. It was risky as the spacecraft would pass a mere 250 kilometers above Mars. Further, during the maneuver, Rosetta would be in Mars’ shadow and would need to rely on the limited battery supply instead of solar panels for power. The risk was that the batteries weren’t designed for the task. So the mission operators put the spacecraft in standby mode and turned off communications to save power.

Ultimately, the Mars flyby proved successful and the spacecraft flew onward to its elusive target. This sweat-breaking maneuver came to be popularly known as “The Billion Euro gamble”. And we got a pretty Mars and Rosetta selfie.

Using the Sun to sail

NASA’s MESSENGER spacecraft was the first ever to orbit Mercury. It was not without its challenges.

Since Mercury lies fairly close to the Sun, any spacecraft on a direct trajectory to the planet is accelerated by the Sun. If MESSENGER had done the same, it would reach Mercury with too high a velocity to get into the planet’s orbit without use of excessive fuel, which is limited. The spacecraft cannot use aerobraking either since Mercury lacks an atmosphere, which is not the case with Venus or Mars.

Gravity assists were again a savior. Mission designers opted for MESSENGER to perform multiple reverse gravity assists––one around Earth, two around Venus and three around Mercury––to slow itself down and ultimately have Mercury capture it in orbit.

Trajectory of MESSENGER spacecraft from launch to orbit insertion around Mercury. Credit: APL

It was critical to have high precision in all the flybys. Flying too close could crash the spacecraft into the planet and flying too high would require excess use of fuel. Either way, getting off target could affect the mission in critical ways.

The solution engineers came up with was to use the Sun’s radiation pressure. Much like how wind can help a boat navigate, solar radiation can help a spacecraft maneuver.

Solar radiation at Earth is not intense enough to exert enough pressure to move a spacecraft in significant ways, though The Planetary Society’s LightSail 2 is certainly innovating in this department. However, Mercury is much closer to the Sun. Since radiation pressure increases by the inverse square law, its effects are about seven times more powerful at Mercury than Earth. This made solar sailing a viable option for MESSENGER.

When passing by Mercury in all of its flybys, engineers sent commands to MESSENGER to align its solar panels in a manner that the radiation pressure can slow down the spacecraft. By solar sailing at just the right angles, the MESSENGER team eliminated the need to use fuel in all flybys without sacrificing accuracy. Reserved fuel was used to increase mission lifetime and get all the fantastic science at Mercury.

MESSENGER was the first spacecraft to successfully use solar sailing as a fuel-free trajectory control method for planetary flybys. For those interested in the nerdy details, the MESSENGER team published a paper on the maneuvers.

MESSENGER image from a Mercury flyby showing lava-flooded craters and vast, smooth volcanic plains. Credit: NASA

Do you know of more such crazy orbital maneuvers by any space missions?


Thank you Epsilon3 for supporting me and powering this article!

<![CDATA[The giant leap for humanity was not stepping on the Moon but getting to Earth orbit]]>https://blog.jatan.space/p/when-we-got-to-earth-orbithttps://blog.jatan.space/p/when-we-got-to-earth-orbitSun, 04 Oct 2020 07:50:51 GMTWhen dabbling with the laws of motion in the 17th century, Isaac Newton first realized that it is indeed possible to send an object out of Earth, into space. As long as an object is shot away from Earth with a high enough velocity, it will reach space and start orbiting our planet. With the launch of the Sputnik satellite on October 4, 1957 onboard a powerful rocket, the Soviet Union achieved exactly that.

Left: Launch of Sputnik satellite on October 4, 1957 by the Soviet Union, kickstarting the Space Age. Right: An engineer besides the finished Sputnik satellite. Credits: USSR

Give a satellite another speed boost, by either launching it on a more powerful rocket or using small thrusters onboard, and it can escape from Earth’s gravitational hold completely. That’s how you can send missions to Venus, Mars, Saturn and beyond. But one of these two things is not quite like the other.

Enter the rocket equation.

The rocket equation is what allows scientists and engineers to quantify and compare the energy required to reach various destinations in space. It tells us the amount of energy a rocket must expend to go from the Earth’s surface to an orbit 250 kilometers above, called low Earth orbit, is almost thrice as much as going from that low Earth orbit to the Moon! Likewise, getting to low Earth orbit costs twice as much energy than what is required to reach Mars from that same orbit.1

Even if we include the energy expenditure not just to reach the Moon from low Earth orbit but to land on it, getting to Earth orbit itself turns out to be about 50% more expensive. In other words, attaining Earth orbit is the first and the most significant barrier to space exploration.

Energy expenditure to travel from one place in space to another, calculated using the rocket equation. Credit: ULA

The giant leap for humanity was not stepping on the Moon but getting to Earth orbit.

The rocket equation doesn’t just dictate how much energy you must spend to reach various destinations in space, but also if you can reach space at all!


The satellite is but a small fraction of the total mass of the rocket that lifts it and yet has an effect on the rocket itself. Therein lies the core problem of rocket science.

Increasing the satellite’s mass, to make it more useful perhaps, also means more rocket fuel is required to put the satellite in the desired orbit. But more fuel makes the system weigh more. This means some more fuel is required to launch the now-heavier system into space. As a thumb rule, fuel requirements increase exponentially with every step increase in mass added to the satellite.

This is how we end up with rockets being mostly fuel and then some metal. Even the mighty Saturn V that sent astronauts to the Moon was 85% fuel, 13% rocket––including the rocket body, its plumbing and parts, and the rest 2% being the Moonbound spacecraft with astronauts sitting inside!

A cutaway illustration of the Saturn V rocket showing the rocket structure and the Moonbound spacecraft on top, which together comprise just 15% of the system’s mass, the rest 85% being fuel. Credit: NASA

At this point, if we were to make Earth more massive, a rocket would have to expend an enormous amount of energy against a more gruesome gravity well. More fuel would be required to get to space and your rocket might be something akin to 9 times more fuel than metal. Increase Earth’s mass further and the fuel-to-mass ratio would start skyrocketing to a point where it’s simply not possible to engineer such a near-all-fuel rocket!

Crunching the numbers in this manner, it turns out that if the Earth was 50% more massive, you simply wouldn’t be able to get to space even with the most energetic fuel combination (liquid hydrogen and liquid oxygen) available in chemical rockets.

Such a massive rocky planet is not imaginary, several of its kind exist. Of the 4,000+ planets around other stars we’ve discovered in our galaxy so far, about a thousand are something scientists call ‘Super Earths’. These are planets which are up to 10 times more massive than Earth and up to twice as large. Beyond that limit, planets don’t remain rocky and start turning into Uranus/Neptune-like gas giants.

Size comparison of a Super Earth (artist’s impression) to Earth and Neptune. Credit: Aldaron, Ginny Keller

Many of these Super Earths lie in the respective habitable zones around their stars i.e. conditions there could support life as we know it. Given that we’ve only searched a small fraction of our galaxy for planets, it’s fair to say there could be millions of Super Earths, many of which could host life.

If intelligent life were to develop on these Super Earths, they’d have a hard time building rockets that get things off-planet. Since even the most energetic chemical rockets won’t get them to space, they might be incentivized to build something with more thrust that can, like nuclear propulsion based rockets. These will likely be far more expensive than chemical rockets but sometimes nature doesn’t give you a choice.

In the 1960’s, US government labs, under Project Orion, investigated a nuclear fission based propulsion system as a potential solution for interstellar travel. For life on ‘Super Earths’, nuclear propulsion based rockets might be the only way to get to space. Credit: NASA

We should be pretty happy that our Earth isn’t massive enough, allowing us to get to space with relative ease, to explore the Moon, the planets, asteroids and comets, and so much more! This is what the launch of Sputnik represents – the advent of the Space Age.

Bound no more

In addition to the physical reason why getting to Earth orbit was so important, there is a biological one.

Life on Earth emerged about four billion years ago. Since then, it has flourished and taken over pretty much every corner of Earth. But in all this time, not a single life form has ever intentionally left the bounds of our home planet and ventured into outer space. The gravitational pull of Earth is gruesome indeed.

The launch of satellites like Sputnik in the 20th century allowed us to break this barrier. For the first time in four billion years, something, and then someone, was intentionally sent to space. A species was no longer Earthbound, even if for fleeting moments on cosmic time scales.



Technically, energy expenditure is not the same as delta-v, which is the actual measure of work required by rockets to reach different destinations. But since energy expenditure is proportional to delta-v, they have been approximated to be the same to make the article tangible for the masses.

<![CDATA[Interviewing Tory Bruno, leading the company that has launched every NASA mission to Mars]]>https://blog.jatan.space/p/interviewing-tory-bruno-ceo-ulahttps://blog.jatan.space/p/interviewing-tory-bruno-ceo-ulaThu, 23 Jul 2020 09:22:00 GMT
Left: The Atlas V rocket of United Launch Alliance (ULA) taking off with NASA’s Curiosity rover inside the fairing. Right: Tory Bruno, CEO and President of ULA. Image credits: ULA

Glued to the Apollo landings, an eight year Tory Bruno became fascinated with rocketry. After graduating as a mechanical engineer, he worked at Lockheed Martin for several years on increasingly complex projects, eventually making the transition from engineer to executive. Today he is CEO and President of United Launch Alliance (ULA)—the company whose rockets have launched every NASA mission to Mars.

Tory is one of my favorite space people and a big inspiration so I was thrilled to get to interview him! The interview was conducted for Supercluster just before ULA successfully launched NASA’s Mars 2020 mission. We talk about ULA’s unique capabilities and future plans to enable solar system exploration.

An article version of the interview follows below. The responses have been edited for brevity, and some links and images have been added for the reader’s benefit.

ULA and its heritage rockets have launched every NASA mission to Mars, ranging from the Mariner 4 in the 1960s, which gave us our first close look at Mars, to modern orbiters like MAVEN, landers like Insight and sophisticated rovers like Curiosity in the more than 50 years since. How has ULA adapted to the ever-increasing scope and demands of NASA’s Mars missions?

There are a few notable things that have become more challenging as NASA has taken on increasingly ambitious Mars missions. In the first category, just the mass of the spacecraft has increased significantly. The Mars 2020 spacecraft carrying the Perseverance rover is more massive compared to anything that has been placed on Mars till date. It’s just under the limit of what our powerful rocket, Atlas V, can carry in its maxed out configuration.

The next thing in these kinds of missions is the orbital insertion accuracy or precision that is required. We’re aiming to put the spacecraft at a point in Mars orbit that is many millions of miles ahead of where Mars is at that moment. The spacecraft needs to arrive at that point when Mars arrives there, and be captured by its gravity and its atmosphere and then descend in specific ways. This takes an unimaginable level of accuracy and the spacecraft itself has very limited ability to adjust its trajectory across these huge distances. If the rocket is off by just the slightest amount, the spacecraft can’t do anything about it. It’ll fly right past Mars, never making the mission. And so one of the most special things about Atlas V is its orbital accuracy. It’s the most accurate rocket in the world. And we continue to improve that every chance we get, to enable increasingly sophisticated missions for NASA.

Another really complex part about the Perseverance rover is its nuclear power source whose heat is used to generate electricity. It adds a level of complexity for pre-launch preparations. We have to install it into the spacecraft very near the end, just a few days before launch. It gets complex further because we also have to pay attention to what we call planetary protection, which essentially means not contaminating Mars with Earth life such as bacteria and viruses. So inside our integration facility, against the rocket 20 stories up in the air, we have constructed a portable clean room to create an ultra clean and sterile environment to conduct what is a multi-day operation to install this nuclear device. All of these things make it a very complicated and unique kind of mission.

Let’s say the rocket blows up—since that’s technically possible, despite all the care you put in. How do you ensure safety on Earth from this nuclear source the rocket is carrying?

So the first thing of course is having all of these very careful procedures to make sure the nuclear power source is handled correctly and safely going into the rocket, and that the rocket itself is well prepared to have a best possible chance of success. Another thing on the rocket side is that for a mission like this with a device like this, we launch out of Cape Canaveral to take our one million pound rocket full of explosives and this nuclear device directly away from shore and out into the broad open ocean area, steering clear from any habitats.

Left: The nuclear device powering deep space missions like Mars 2020. Credit: NASA. Right: Radioactive plutonium-238 dioxide pellet, used in NASA’s Cassini mission as a power source. Credit: Los Alamos National Laboratory

Now I’ll jump to the device side itself. The Plutonium-238 source emits alpha radiation, which can be stopped literally with just a sheet of paper. It cannot penetrate your skin. And so the containing device itself entirely stops the alpha radiation. As a person, your only danger from it would be if you were to ingest it or inhale it. Next, the source is actually made in the form of plutonium dioxide, an extremely stable compound and with a very high melting point, which makes it very difficult to vaporize it. This makes it even harder to get the source in that state where you could potentially get it inside your body if you somehow even managed to get near it.

Third, the device is packaged in a reentry shell, designed to survive a rocket failure itself. Even if a failure occurs at a very high altitude, say in our upper stage before it’s orbital, the protective shell is capable of bringing the device all the way back down to Earth despite the heat of a reentry. Historically, that has actually happened twice, though not on our rockets. During these failures, these devices in their shells came all the way down to Earth, landing in the ocean if I remember correctly, without being breached and were recovered and used again in later exploration missions. So this is a very safe energy source.

Mars 2020 costs north of $2 billion, as did its predecessor Curiosity. What capabilities and assurances does ULA provide that NASA trusts you with these flagship robotic missions instead of choosing other launch providers?

In addition to the unique precision capabilities we discussed, built into what we offer, and really into our culture, is complete transparency. From even before the contract was awarded, we have been completely open with them. They’re in our facilities, they have access to every bit of engineering data we produce, they can sit in every review and so on, meaning they know every step of the way what is happening with their launch, and have a voice in what they’re comfortable with, or not so. So we’re really doing this together as a partnership.

Let’s talk about precision. Even a small error in injecting spacecraft on trajectories to Mars could mean loss of the entire mission. How do ULA rockets deliver such precision?

It’s really in some very sophisticated guidance algorithms, as well as how the propulsive elements of the rocket operate together. People often think of accuracy just in terms of the quality of sensors, like the IMU, gyros, GPS and so on. But knowing where you are and knowing where that trajectory flies is only one element of accuracy. You also have to be able to actually control the path of the rocket and especially the conditions of that upper stage at the moment you want to separate from the spacecraft. Our rockets can very precisely control when the thrust is on, when it is off and exactly how repeatable that transition is from on to off so as to compensate for that with the guidance.

We also have very sophisticated algorithms, software if you will, to deal with things that occur during flight that are not ideal, like flying through atmospheric conditions with different densities. These algorithms can account for all of those deviations happening during flight and make autonomous adjustments to the trajectory, and have the rocket still arrive at that point in space at that moment in space when we intend to separate from the spacecraft and then very precisely let it go. All of that stuff working together is our secret sauce. If you were NASA, you would get to see all of that. No one else does (chuckles).

In 2018, ULA launched NASA’s InSight mission to Mars alongside the first interplanetary CubeSats (small satellites), the MarCO pair. Their job was to relay telemetry of the InSight landing. While typical Marsbound spacecraft can correct for minor variations in their trajectories, CubeSats can’t do so to the same extent. So I imagine unless the rocket does its job with mission-critical precision, such CubeSats would never reach Mars and be able to do their job. How did the Atlas V manage such synchronization?

So we’re not well known for this, but we fly a lot of CubeSats, and our Centaur upper stage has standard accommodations for those. When we were talking about the orbital insertion accuracy of the main spacecraft, all of that applies to the CubeSats too of course. But in addition, the integration of the CubeSats and its deployment device from NASA and the accommodating mechanism on our upper stage also play an important part. We again work hand-in-glove with them so that we both understand how our upper stage interacts with their deployment device to push the CubeSats within the desired level of accuracy without having to worry about them not having enough correction capability during traverse as in a standard spacecraft.

Speaking of that upper stage, the Centaur III, does it offer other benefits for deep space missions than precision orbital injections?

Well, yes. You will observe when we launch Mars 2020 at the end of next week that we have giant two hour launch windows. That is very unusual. Other launch providers can often only do an instantaneous launch window. What’s going on there is one has to wait for the Earth to rotate around and align with the path out to Mars. So the launch window opens up and they gotta go within five minutes and that’s it for the day.

But because of the performance of our main booster and the ability of the Centaur upper stage to compensate, we can stretch that tiny window out to actually a big two hour span. Having that flexibility and versatility gives us even more opportunities, in cases like bad weather or say problems at the launchpad, to still take off earlier than would otherwise be possible. The performance of the Centaur also allows us to do long coasts to come around the planet and get lined up exactly right even if we didn’t launch at the ideal time if it were instantaneous, and then provide that insertion accuracy that we talked about.

While you are launching NASA’s Lucy next year, SpaceX has won contracts to launch NASA’s upcoming DART and Psyche missions. How do you plan on ensuring ULA’s continued legacy of enabling Mars missions in the future and others in the solar system? Where does your upcoming rocket Vulcan-Centaur fit in this scheme?

We really like to focus on the most difficult space missions that require the greatest flexibility and the greatest precision from the rocket. That is where we have made our investments and the Vulcan rocket debuting next year doubles down on that. It provides more launch flexibility for these big launch windows. It has a Centaur V upper stage, which is an upgraded version of the current Centaur III.

The Centaur V will have over two times as much energy and twice as much thrust, which matters in certain circumstances, and a whole host of things to further improve both the system’s accuracy and the size of the spacecraft that it can deliver for interplanetary missions. It’ll also have the ability to go for even longer durations between burns, to enable it to take on even more complex trajectories for ambitious future missions.

ULA’s upcoming Centaur V upper stage compared to the existing Centaur III in their rockets. Credit: ULA

Two of the three companies NASA recently selected for returning humans to the Moon as part of its Artemis program will be using the Vulcan rocket. To what extent are you guys involved in Artemis? Do you see this as a key part of your vision to have 1000 humans working in space in 30 years?

Yes, I absolutely do. So we are deeply involved in those two opportunities to put humans on the Moon again. I’ll also put in a plug for our exciting mission to take the first commercial lander to the lunar surface, the Peregrine lander built by Astrobotic. That will launch ahead of the human missions as part of the Artemis program, flying next year on Vulcan’s maiden flight.

And yes, Artemis absolutely is the very first step of the Cislunar 1000 vision of this self-sustaining cislunar marketplace and economy, and people living permanently off-planet, all of which can be enabled thanks to the discovery of water on the Moon.

India played a very important part in its discovery with the Chandrayaan spacecraft. A year later, we had the honor of following that up with our LCROSS mission, where we smashed a Centaur into a crater on the Moon’s south pole, throwing up a water plume that a following spacecraft could fly through and directly measure. So together we have made the discoveries that are going to make this vision possible.


It was fun talking with you Jatan, those were great questions. And my regards to your readers – This is such an exciting time to be in space and boy, are we excited about launching the mission!

Originally published at Supercluster, a website dedicated to telling humanity's greatest outer space stories.


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<![CDATA[Everything you need to know about SpaceX’s historic launch of NASA astronauts]]>https://blog.jatan.space/p/spacex-to-launch-nasa-astronauts-on-historic-flighthttps://blog.jatan.space/p/spacex-to-launch-nasa-astronauts-on-historic-flightWed, 27 May 2020 13:31:46 GMTUpdate: Launch was successful on May 30 followed by successful docking and entry of astronauts into the International Space Station on May 31! 🚀️👨‍🚀

SpaceX is set to launch two NASA astronauts onboard its Falcon 9 rocket in just a few hours, currently scheduled at 8.33 PM UTC on May 27. After NASA retired the Space Shuttle in 2011, this is the first time the US will be launching astronauts from its own soil. The astronauts will arrive at the International Space Station (ISS) a day later on SpaceX’s crew capsule, called Crew Dragon / Dragon 2, which will fly on top of the rocket.

SpaceX Crew Dragon Demo-2 mission patch (center) and NASA astronauts Douglas Hurley (left) and Robert Behnken (right). Credits: NASA

NASA’s Commercial Crew Program

NASA had originally planned for its Ares I rocket, part of the wider Constellation program to return to the Moon, to take the shuttle’s place. But in a radical move, the Barack Obama administration cancelled the program in 2010 and instead tasked NASA with helping companies develop human spaceflight capability commercially. The idea behind the Commercial Crew Program is that in addition to opening up the low-Earth orbit and the ISS to private players, it would free NASA to build spacecraft and rockets for deep-space missions to the Moon and beyond.

Atlantis landed at the Kennedy Space Center on July 21, 2011, bringing the Space Shuttle program to an end. Credit: NASA

Historically, NASA has designed and owned human spaceflight technologies by itself, only hiring contractors to build the systems. But with Commercial Crew, so long as the companies meet the agency’s mission and safety requirements, they are free to design the system any way they’d like, and NASA would fund them.

After evaluating proposals from several companies, NASA chose SpaceX and Boeing in 2014 to develop human-rated capsules to ferry astronauts to and from the ISS, to be launched on existing rockets. SpaceX has been awarded a cumulative $3.1 billion (Rs 23,466 crore) to develop its proposed Crew Dragon while Boeing won $4.8 billion (Rs 36,334 crore) for its Starliner. These companies also get to tap into NASA expertise and facilities as and when they need.

The important thing about the Commercial Crew Program is that the companies own and operate their own hardware and infrastructure so much so that the astronauts even train there, instead of at NASA, as has been the tradition. SpaceX and Boeing can even use the technology to carry private astronauts to space if they wish, regardless of NASA missions.

But for almost a decade in the meantime, the US has had no ability to transport astronauts to and from space. To continue their investment in the ISS, NASA has been buying increasingly expensive seats for US astronauts on Russia’s Soyuz rockets. And to send supplies, NASA has been running the similarly commercial COTS program. As part of this agreement, SpaceX has been flying its cargo-only Dragon 1 spacecraft to the ISS for over seven years, so human spaceflight will only be an added business for the company.

How do they fare against the Space Shuttle?

While the Space Shuttle typically carried five to seven astronauts, Crew Dragon and Starliner will each carry a maximum of four, despite having a capacity for seven. The shuttle used to cost $214 million per seat (Rs 1,619.88 crore) whereas NASA pays $55 million per seat to SpaceX (Rs 416.32 crore) and $90-99 million per seat to Boeing (Rs 681.25-749.38 crore). The smaller Russian Soyuz rocket, with a maximum capacity of three astronauts per launch, currently costs about $90 million per seat. This isn’t a fair comparison as the shuttle also had extra space for cargo and a robotic arm. The shuttle could fit a Crew Dragon, Starliner and Soyuz along its length!

But like the Space Shuttle, Crew Dragon and Starliner are partially reusable. Each human spaceflight by SpaceX will be on a brand new Crew Dragon, which will be refurbished for future cargo flights. Boeing on the other hand plans to reuse Starliner even for human flights.

SpaceX milestones

SpaceX’s upcoming mission to safely ferry astronauts to and from the ISS, dubbed Demo-2, represents the final demonstration in a series of milestones to get NASA’s okay for human spaceflight.

SpaceX launched the Demo-1 mission last year – an uncrewed Dragon capsule that autonomously docked to the ISS and subsequently returned safely to Earth. Boeing hit a snag last year when its similar uncrewed Starliner mission failed. Boeing will have to repeat the mission with success before it can perform a crewed test.

Artist’s rendering of a SpaceX Crew Dragon docking with the International Space Station. Credit: SpaceX

The Demo-2 mission had originally been planned for launch last year. But on April 20, 2019, the capsule from Demo-1 was destroyed during a static fire test, ahead of its planned use for an in-flight abort test. SpaceX traced the cause to a faulty valve and fixed the issue.

In January 2020, SpaceX successfully demonstrated the Crew Dragon’s autonomous ability to detect a rocket failure, jettison itself mid-flight and gently splash down. For emergencies on the launchpad, before liftoff, such as a fire, SpaceX also successfully demonstrated rescue operations for astronauts last month.

SpaceX has also undertaken 27 parachute tests to make sure the mechanism the capsule will use to land back on Earth from space or after an in-flight abort is extremely reliable. Crew Dragon’s ability to return astronauts safely to Earth will be available throughout the mission.

Crew Dragon in-flight abort test (left and center) and its Mk III parachute test (right) with a dummy mass. Credits: SpaceX [1][2]

Launch preparations

The preparations for SpaceX’s Demo-2 mission have been going strong despite the coronavirus pandemic. The astronauts, Robert Behnken and Douglas Hurley, have been practising various mission phases with simulation runs along with the SpaceX mission operations team. On the mission, Behnken and Hurley will be wearing customized pressurized spacesuits designed in-house by SpaceX.

The Crew Dragon has a touchscreen interface, a first on any human-rated spacecraft. The astronauts, who have previously been on two Space Shuttle flights each, have said the touchscreen has taken some adjusting but works just fine. But since Crew Dragon is designed to be autonomous throughout the flight, including during the nail-biting ISS docking phase, the astronauts will hardly need to take manual control.

Both NASA and SpaceX are advertising the historic importance of the launch in different ways. Astronaut Hurley piloted the last Space Shuttle mission and is now commander of the Crew Dragon. The Falcon 9 launching the capsule will take off from Launch Complex 39A, the same launchpad used to send humans to the Moon. NASA even revived their much loved ‘worm logo’ and had it painted on the Falcon 9.

Top and bottom left: Crew Dragon mated to the Falcon 9 rocket, which flaunts the NASA worm logo, in the hangar at Launch Complex 39A. Right: Falcon 9 on the launchpad. Credits: SpaceX [1][2][3]

After boosting the astronauts towards the ISS, we’ll also get to see the Falcon 9’s first stage attempt yet another drone ship landing, for an added dash of wholesomeness.

NASA administrator Jim Bridenstine has urged space enthusiasts not to travel to view the launch, requesting them to watch it online instead. This will be the first crewed US spaceflight mission to not include public presence, except select members of the press.

Top: NASA astronauts Doug Hurley and Bob Behnken at Launch Complex 39A with the Falcon 9-Crew Dragon in the background. Bottom: SpaceX’s Crew Dragon atop Falcon 9, prior to its first uncrewed test flight in March 2019, to its right is the retractable crew access arm. Credits: SpaceX, NASA

That hasn’t stopped SpaceX and NASA from marketing the launch in digitally enticing ways. For example, SpaceX launched an online game that gives you the same controls as in Crew Dragon, which NASA astronauts will use; your task is to manually dock with the ISS. NASA even challenged Kerbal Space Program players across the world to recreate the Demo-2 mission and share their game footage. (Kerbal Space Program is a popular game based in which players build and launch spacecraft to perform custom missions, making many of the same calculations and decisions that an engineer at ISRO might.)

What’s next?

If the launch is successful and if Crew Dragon docks with the ISS, the astronauts will join the three already at the station to conduct experiments for two to three months, (although their mission could be extended for up to seven months). After this, they will return to Earth in Crew Dragon and splash down in the Atlantic Ocean. The capsule will also drop its trunk containing trash collected from the ISS en route into the atmosphere to burn up.

If SpaceX’s Demo-2 mission is successful, the company can begin executing contracts to carry astronauts on six more ISS flights, the second in 2020 itself. If the mission is unsuccessful, the next steps will depend on the nature and extent of failure.

India’s Gaganyaan program aims to develop the same human spaceflight capability, albeit by the state-funded ISRO, by the end of 2021. Perhaps more notably, the US’s return to human spaceflight comes around the same time China successfully tested and launched its next-generation human space capsule. Chinese astronauts will use this capsule to dock with their upcoming space station – a large, modular spacecraft – and eventually for flights around the Moon. Meanwhile, the US awaits its controversial super-heavy-lift Space Launch System rocket to be ready next year to test its deep-space human spaceflight abilities.

For NASA, opening up human spaceflight in Earth orbit to commercial entities is only the first step. It has doubled down on extending such public-private partnerships by funding commercial companies to send both cargo and humans to the Moon’s surface as part of its Artemis program, in the coming decade.

In all, human spaceflight is progressing at a rapid pace across the globe. This decade is full of milestones to look forward to, starting with the first ever launch of astronauts by a private space company.

Originally published at The Wire.


<![CDATA[Most anticipated space launches in 2020]]>https://blog.jatan.space/p/space-launches-2020https://blog.jatan.space/p/space-launches-2020Sun, 05 Jan 2020 14:28:32 GMTUpdate: This article was written at the start of 2020 before COVID-19 happened. As such, most of the missions haven't materialized. Feel free to check out the Space Missions section instead.
Most anticipated space launches in 2020. Illustration credit: Jatan Mehta

2019 has been a thrilling year for space exploration with over 100 space launches. 2020 promises to be even more exciting with almost double the launches planned! Here are the most anticipated space launches of 2020, which include missions to Mars, Moon landings, Sun orbiters, new breeds of rockets and progress in human spaceflight. That’s a lot of space to cover (pun intended), so grab a coffee and let’s get the juices flowing.

Four missions to Mars

Four missions are being launched to Mars in 2020. Illustration credit: Jatan Mehta, image credits: CNSA, ESA, NASA, UAE Space Agency

The fourth planet from the Sun is about to get some love. NASA’s famed Curiosity rover will be getting two friends in the form of NASA Mars 2020 and the ESA Rosalind Franklin. Both craft are to be launched in July 2020, separately, and they will rove and study the Martian surface to look for signs of past and present life. Both rovers boast a drill and advanced instrument suites for study of the Martian surroundings.

Hot on the heels of a very successful farside Moon landing with Chang’e 4, China aims to take it up a notch in 2020. It is targeting Q3 for the launch of its first indigenous Mars mission Huoxing-1 (HX-1), consisting of an orbiter and a rover. A successful mission would be a sizeable addition to China’s growing space prowess.

The United Arab Emirates are also joining the Mars club with their Hope orbiter. Hope will be UAE’s first interplanetary mission and it aims to study Mars’ climate variations from orbit.

When all these four spacecraft reach Mars in 2021, they’ll add to the existing portfolio of eight machines on Mars – six in orbit and two on the surface. What a year 2021 would be when we can say to our kids that there are currently a dozen spacecraft studying Mars and they’re all helping us build a future there.

Return of astronauts from US soil

Return of astronauts to the ISS from US soil in 2020 will be onboard SpaceX and Boeing capsules. Illustration credit: Jatan Mehta, image credits: SpaceX, Boeing

After retiring the Space Shuttle in 2011, the US lost its capability to ferry astronauts to and from space. It hopes to regain the same in 2020. As part of NASA’s commercial crew program, both Boeing and SpaceX will launch their first human spaceflights to the International Space Station (ISS) this year.

Boeing had an unsuccessful uncrewed test flight of its human-rated Starliner capsule last December, so its Q2 2020 target for carrying astronauts to the ISS will likely get delayed until end of year. SpaceX may leap ahead as it has an abort test planned on January 11 of its capsule Crew Dragon. If successful, it will be followed by a crewed flight in Q2 2020, carrying two US astronauts to the ISS. A successful mission would make SpaceX the world’s first private company to send humans into space.

In all, NASA hopes to end reliance on Russia for ferrying astronauts and thus also forgo the increasingly expensive use of Russian rockets.

Two Moon landings

India and China aim for another round of Moon landings in 2020. Illustration credit: Jatan Mehta, image credits: ISRO, CNSA

With ISRO’s Chandrayaan 2 lander crashing on the Moon’s surface last year, the organization is set to give the landing another try with Chandrayaan 3. Chandrayaan 3 will consist of a lander and a rover, not an orbiter as the Chandrayaan 2 orbiter is functionally nominally. The lander will carry instruments like a seismometer and a thermal probe, while the rover will carry spectrometers to analyze the lunar surface. A successful lunar landing will make India the fourth organization in the world to achieve the feat.

China is gearing up to launch the Chang’e 5 spacecraft in 2020 end – its first lunar sample return mission. Once it lands in a geologically young and unique region on the Moon, the lander will dig 2 meters below the surface and scoop out up to two kilograms worth of lunar soil. A capsule carrying the sample will perform an autonomous rendezvous and docking with a return module in orbit, which will then bring the sample to Earth.

It is notable that the rendezvous and docking will be practice for a future Chinese human mission to the Moon. If successful, Chang’e 5 will represent China’s third successful Moon landing, each a notch above the last. All of this in a decade when no one else seems to be nailing lunar landings. Third time’s the charm I guess.

Return of the Super Heavy-Lift rockets

2020 could see a return of the Super Heavy-Lift rockets, the Saturn V kind. Illustration credit: Jatan Mehta, image credits: NASA, SpaceX

If there’s a jackpot to be won this year, it is the hopeful return of the Jedi Super Heavy-Life rockets. The Apollo Moon landings, considered to be one of humanity’s best achievements, were possible in major part thanks to the existence of the behemoth rocket Saturn V. Since then, no such super heavy-lift rocket has existed. If all goes right, this situation can change with the launch of two much awaited rockets.

First is a hopeful November launch of the Space Launch System (SLS), NASA’s vehicle of choice for their future deep space exploration efforts. SLS’s first mission will be called Artemis I, and will launch the uncrewed Orion spacecraft on a trip around the Moon, alongside launching 13 CubeSats. A successful launch is critical for NASA to be on target for landing humans on the Moon by 2024.

In its maxed out configuration, the SLS can place 130,000 kg worth of mass in Low Earth Orbit, more than twice the current best SpaceX Falcon Heavy can do.

The second super heavy-lifter is SpaceX’s Starship, which in the Elon Musk timeline goes orbital sometime this year rather than later. The SpaceX Starship will be as capable as the SLS. In its maxed out configuration, Starship will be even more powerful and is central to Musk’s Mars colonization plans.

Super heavy-lift rockets are needed for effective deep space exploration and if we want to have any hope of colonizing the solar system.

New Medium-class rockets

New Medium-class rockets enter the game in 2020. Illustration credit: Jatan Mehta, image credits: Arianespace, JAXA

Meanwhile, SpaceX has already democratized traditional access to space by massively lowering launch costs with its medium-lift rocket Falcon 9. This year it will double down on slashing prices further by reusing more parts of the rocket and more often so.

To survive in such a post-SpaceX market, ESA is aiming for the maiden launch of its Ariane 6 medium-class rocket. Ariane 6 will be equally capable as ESA’s current workhorse Ariane 5 but will cost half as much. The Japanese aim to launch a similarly capable rocket, the H3, to replace their costlier H2B.

Heated competition in the small rocket space

A plethora of cost-efficient small satellite launching rockets enter the market in 2020. Illustration credit: Jatan Mehta, image credits: Arianespace, Rocket Lab, ISRO, Virgin Orbit, Firefly, Relativity Space

Not all new rockets need to be big––in fact, the opposite is more true. Smaller satellites, notably CubeSats, have become increasingly easier to make and operate, and so a market for rockets has arisen to deliver such small payloads at a fast cadence.

New Zealand based Rocket Lab already boasts nine successful flights of its Electron rocket, designed specifically for the commercial small satellite market. In addition to ramping up Electron’s launch frequency, the company will attempt to recover rockets boosters using helicopters. The launch price cuts achieved thereby will help Rocket Lab maintain its lead for small satellite launches over new competitors coming online this year.

The first of these competitors is billionaire-entrepreneur Richard Branson’s Virgin Orbit. With the successful test flight of its long-awaited Launcher One rocket in December 2018, Virgin Orbit now aims for a steady launch pace to deliver small satellites starting as early as Q1 2020.

Also notable in this category is ISRO’s Small Satellite Launch Vehicle (SSLV), which will be a smaller cousin to the Polar Satellite Launch Vehicle (PSLV). While the PSLV can lift at best 3,800 kg to the Low Earth Orbit, the SSLV will can lift 500 kg. ISRO has said the SSLV’s USPs will be low cost and a faster turnaround time. Its design is ready and the first SSLV test flight is expected to happen in Q1 2020, followed by a second test launch sometime later this year.

In the same space, the European Vega-C is set to replace the Vega spacecraft as ESA’s vehicle of choice for lighter satellite launches. The American Firefly’s Alpha 1 and Relativity Space’s Terran 1 rockets will take off the first time too this year if all goes to plan for these new entrants.

Two Sun orbiters to join the one

Two spacecraft dedicated to studying the Sun to be launched in 2020. Illustration credit: Jatan Mehta, image credits: ESA, ISRO

In 2018, NASA launched the Parker Solar Probe on a mission to go right into the Sun’s atmosphere and study it up close to unravel its mysteries! ESA wishes to join the game with its Solar Orbiter, targeting a February 2020 launch.

On the other hand, ISRO is launching Aditya-L1 sometime in mid 2020 to conduct uninterrupted observations of the Sun from afar. It will be placed at the first Lagrangian point (L1) between the Sun and Earth, where the dynamic gravitational attraction between these two bodies roughly cancel out.

The L1 point is not a point as much as a small region in space. It has been host to multiple solar weather monitoring and science observation spacecraft in the past, such as SOHO, ACE, WIND, DSCOVR, etc. Aditya-L1’s observations will complement data from the Parker Solar Probe and Solar Orbiter.

India and China push for human spaceflight progress

Both China and India push for human spaceflight progress in 2020. Illustration credit: Jatan Mehta, image credits: ISRO, CNSA

Preparations are in full swing for India’s Yuri Gagarin moment. Astronaut candidates are undergoing training in Russia for ISRO’s indigenous Gaganyaan mission targeted for December 2021. To that end, ISRO is gearing up for the first test flight of Gaganyaan in December 2020, without any crew. This would be followed by another test in mid 2021 before the actual crewed mission in December.

China, on the other hand, is no stranger to the astronaut game. They have already built and flown two space stations for their taikonauts in the past – the stations Tiangong-1 and Tiangong-2. Now China wants to build its biggest space station ever, the Tiangong-3. It will be as big as the Russian Mir i.e 1/5th the size of the ISS. The core module of Tiangong-3 is targeted for launch in 2020 using China’s heavy-lift rocket Long March 5. The same Long March 5 will also do the heavy-lifting of the Chinese Chang’e 5 and HX-1 Mars missions.

Internet from space

Internet from space may become a reality in 2020. Illustration credit: Jatan Mehta, image credits: SpaceX, OneWeb

SpaceX wants to offer internet services globally using thousands of Starlink satellites. In 2019, SpaceX successfully launched two batches of 60 Starlink satellites each and intends to do 10 such launches in 2020, pushing the total count over 700. With that, they hope to start providing initial satellite internet services.

Likewise, its competitor OneWeb is prepping the first batch of its satellites to be launched in January atop a Russian Soyuz rocket. After several launches over the course of the year, they too hope for more than 600 satellites to be in orbit, so they can start providing internet services to the USA before going global.


2020 is truly an action-packed year for space exploration. Even if half of the above mentioned launches come true, that’ll be substantial progress as our species makes a slow but steady headway towards space colonization.

Republished by The Wire.


<![CDATA[Gravity assist: The simple physics trick that’s allowed humanity to explore deep space]]>https://blog.jatan.space/p/gravity-assist-the-simple-physics-trick-thats-allowed-humanity-to-explore-deep-spacehttps://blog.jatan.space/p/gravity-assist-the-simple-physics-trick-thats-allowed-humanity-to-explore-deep-spaceSun, 07 Jul 2019 17:02:40 GMT
An artist’s rendering of the Voyager spacecraft approaching Saturn, using a gravity assist from Jupiter. Credit: NASA JPL

Traveling the vast distances of space isn’t cheap. It costs spacecraft time, fuel and money. Fortunately, nature offers free help along the way which mission designers are happy to take.

They’re called gravity assists.

In these maneuvers, a spacecraft exchanges its momentum in a close encounter with a planet to gain velocity. Gravity assists have been used in numerous interplanetary missions to propel spacecraft towards their destinations.

Gravity assists are also useful because it’s not practical to simply add more fuel to power a spacecraft. Adding more fuel makes it weigh more. This means more fuel needs to be added to the rocket to launch the now-heavier spacecraft. Since including extra fuel also increases the rocket’s mass, more fuel is needed to carry that fuel, and so on.

As a thumb rule, the fuel requirements increase exponentially with more mass added to the spacecraft. Heavier spacecraft may require a more complex rocket to be built to meet the demands. Such increases in cost and technological complexity can be saved by using gravity assists.

They also allow us to do things that are beyond our current abilities. In the 1970s, some of the most ambitious spacecraft in history were launched: Voyager 1 and 2, both by NASA. They would go on to escape the Sun’s gravity and exit the Solar system. Voyager 1 entered interstellar space in 2013 and Voyager 2 did so in 2018. And it wouldn’t have been possible without gravity assists.

After launch, the twin Voyagers didn’t have enough velocity to escape the Sun’s gravity straightaway. It was and remains impossible for us to build a rocket powerful enough to achieve that. The Titan III rockets that launched the Voyagers (10 days apart) left them with enough energy just to get to Jupiter.

To overcome this problem, the Voyagers were made to swing around the gas-giant to acquire the velocity boost needed to escape the Sun. As each spacecraft approached Jupiter, the planet’s gravity sped it up. Such a close gravitational encounter with a planet is called a flyby.

Voyager 1 & 2 trajectories, showing gravity assist maneuvers at Jupiter & Saturn to escape the Solar system. Credit: NASA

The extra velocity comes from the planet itself. It’s worth remembering that the spacecraft also has some mass, even if insignificant compared to Jupiter. Gravity works both ways: the spacecraft pulls on Jupiter—even as Jupiter pulls on the spacecraft—slowing it ever so slightly in its orbit around the Sun.

Because total momentum, a product of mass and velocity, is always conserved in an interaction, the momentum lost by Jupiter is gained by the spacecraft. The velocity loss for Jupiter in this scheme is so negligible as to be unimportant. But the velocity gained by the spacecraft in just one such interaction is quite significant, as in the case of Voyagers.

Voyager 2 had a velocity of ~10 km/s when it approached Jupiter. After the gravity assist, the velocity increased to ~25 km/s.

Voyager 2 spacecraft velocity as a function distance from the Sun, compared to the Solar system escape velocity. Credit: NASA

Since the Voyager missions, gravity assists have been used to get everywhere in the Solar system. The NASA Cassini probe to the Saturn system weighed over 5,000 kg at launch—on the heavier side for interplanetary missions. The two Voyagers weighed less than 900 kg each. The rocket that launched Cassini, Titan IV, was not significantly more powerful than the Titan III. Because the probe was heavy, a single gravity assist from Jupiter wouldn’t cut it. So Cassini flew towards the Sun first before flying away: it took two gravity assists from Venus, one from Earth and one from Jupiter to reach Saturn.

The ESA Rosetta spacecraft studied the comet 67P after an arduous journey. To rendezvous with the comet, Rosetta had to match the comet’s high velocity, involving three flybys around Earth and one around Mars.

Gravity assists can also be used to slow down a spacecraft. This works when the spacecraft approaches the planet in a direction opposite to the planet’s orbit around the Sun. In this scenario, the spacecraft would lose momentum to the planet.

But why slow down in the first place?

Missions to the inner Solar system face different challenges from those to the outer Solar System. Consider the most recent mission to Mercury—the ESA BepiColombo—that launched on October 20, 2018.

Mercury lies deep in the Sun’s gravitational well. This means a spacecraft going towards Mercury will be constantly accelerated due to the Sun’s gravity. On such a trajectory, BepiColombo would reach Mercury with a velocity too high to allow itself to be captured into orbit.

One way out is retrograde thrusting: to fire the engines through thrusters pointing in the direction of flight as a form of braking. However, this would consume a lot of fuel, and as we’ve seen, that’s not practical. Mercury also lacks a significant atmosphere like Venus, Earth or even Mars, so aerobraking isn’t an option either.

The BepiColombo mission designers approached the problem with a gravity-assist solution. The probe will use one gravity assist from Earth, two from Venus and six from Mercury itself to slow down. With each flyby, the probe will shed a part of its abundant orbital velocity. After multiple flybys, it will be slow enough to have Mercury capture it. BepiColombo is currently scheduled to orbit Mercury in December 2025 if everything goes according to plan.

Animation showing BepiColombo’s trajectory from launch to getting into Mercury’s orbit. Note the multiple flybys used around Mercury. Credit: Phoenix777 on Wikipedia

The NASA Parker Solar Probe was launched this year to study the Sun by being in its atmosphere. As with BepiColombo, Parker will be constantly accelerated when approaching the Sun, making it difficult to get so close to it. Over six years, Parker will use seven gravity assists from Venus to achieve its final orbit in 2024. This orbit will take it to its target destination: 6 million kilometers from the Sun’s surface, about 10 times closer than Mercury.

The Parker Solar Probe trajectory utilizes seven gravity assists from Venus to achieve its closest pass to the Sun. Credit: NASA

The physics of gravity assists can also be used to change an orbit’s inclination.

In 1990, the NASA-ESA mission Ulysses, first to study the Sun’s poles, was launched. To do so, Ulysses had to leave the orbital plane of the solar system — the plane in which the eight planets orbit the Sun — and achieve a very tilted orbit.

In 1992, Ulysses took a gravity assist from Jupiter, near its north pole. The planet’s strong gravity bent the spacecraft’s trajectory southward, putting the latter in an orbit that took it past the Sun’s north and south poles at an inclination of 80°.

The gravity assist is a versatile instrument in the mission designer’s toolbox. Future space missions could utilize gravity assists to accomplish even more — like having an orbiter use Pluto’s moon Charon to explore the entire Plutonian system.

Originally published at The Wire.


<![CDATA[How spacecraft are protected in space from extreme temperatures]]>https://blog.jatan.space/p/space-blankets-and-how-the-teamindus-spacecraft-will-survive-in-space-21f779ca7291https://blog.jatan.space/p/space-blankets-and-how-the-teamindus-spacecraft-will-survive-in-space-21f779ca7291Mon, 09 Apr 2018 13:08:48 GMTOut there in the harsh environment of space, spacecraft must deal with extreme hot and cold temperatures. The spacecraft don’t just need to survive the extreme temperatures but also function in such harsh environments throughout their missions.

Difficulties of managing heat in space

Spacecraft can experience temperatures in space that are either too hot or too cold. Solar radiation can heat the spacecraft to hundreds of degrees, posing a risk to their survival. On the other hand, being eclipsed from the Sun when behind a celestial body (say Earth) can be too cold for the spacecraft, sometime as cold as hundreds of degrees below 0° Celsius.

Experiencing either too hot or too cold temperatures beyond the survival limits of the spacecraft can permanently damage it and its components can cease to function as intended. Depending on the environmental conditions, the spacecraft components need to be heated or cooled down. It is particularly difficult to do so efficiently because:

  • Electric power onboard the spacecraft is too limited to make use of heaters excessively.

  • The environmental conditions can drastically vary depending on the mission phase, making it difficult for one solution to adapt to all needs.

This is where a technique called multi-layer insulation (MLI) comes in.

Preserving heat using a multi-layer space blanket

Crucial parts of a spacecraft are usually covered with multiple layers of a highly insulating material called Kapton. Between each successive Kapton layer, another insulating material called Mylar is used.

A closeup of a multi-layer insulation material. Source: Wikipedia

Such multi-layer insulation (MLI) allows minimal heat to pass through either way, thereby maintaining the desired temperature on the spacecraft parts it is designed to protect. Materials used in MLI are also very stable at a wide range of temperatures and do not deform easily. They are thus useful in a wide variety of cases.

#1: Protection against excessive heat

Notably, NASA’s James Webb Space Telescope (JWST) to be launched in 2020 will use a MLI sunshield to protect its optics. The sensitive optics must function at extremely cold temperatures and will get deformed if exposed to excess heat.

Cross-section of JWST’s MLI sunshield that protects the sensitive optics from the Sun’s heat. Source: NASA JSWT

Interestingly, the insulating material used between the Kapton layers is no material at all, but vacuum. Vacuum itself is a poor conductor of heat and thus enables the MLI setup to preserve the optics, allowing us to explore the Universe.

#2: Protection against excessive cold

Alternately, missions sent to the outer solar system need to be warm enough to function. At such large distances from the Sun, the spacecraft quickly start losing heat to deep space. A lot of the electronic components can cease functioning at this point or the craft can also be permanently damaged.

NASA’s New Horizons spacecraft on a flyby mission to Pluto was thus fully covered with a gold-colored MLI to retain internal heat.

NASA’s New Horizons spacecraft fully covered with a gold-colored MLI (multi-layer insulation) to retain internal heat. Source: Wikipedia

#3: Why not just use a thick block shield instead?

Using one thick block will conduct heat from one end of the spacecraft to the other. A multi-layer insulation made up of different material means that each layer is hotter/cooler than the other and the heat dissipation is thus minimized. Additionally, a thick shield would increase the weight of the spacecraft which is not desired. MLI on the other hand is quite lightweight.

#4: Protection from impacts

Despite being thin, an MLI covering also provides protection to the spacecraft from micrometeorite impacts. If say, an outer facing layer is damaged, the rest of the layers still serve the purpose because redundant layers are used to enhance reliability.

So that was a sneak peek into a type of thermal protection technology used in space missions.

<![CDATA[How SpaceX's Falcon Heavy could enable fantastic science in the outer solar system]]>https://blog.jatan.space/p/how-spacexs-falcon-heavy-could-enable-fantastic-science-in-the-outer-solar-system-a051d65a2b0ahttps://blog.jatan.space/p/how-spacexs-falcon-heavy-could-enable-fantastic-science-in-the-outer-solar-system-a051d65a2b0aWed, 28 Mar 2018 10:31:00 GMTFebruary 2018 saw the successful launch of SpaceX’s Falcon Heavy, making it the most powerful rocket in operation. It is capable of launching more than 2x the payload to Low-Earth Orbit than the next best which is ULA’s Delta IV Heavy.

Falcon Heavy launch by SpaceX. Credit: John Kraus.

Here are some numbers to give you an idea of some of the most powerful rockets we have in operation:

Maximum payload to Low-Earth Orbit:
1. Falcon Heavy (SpaceX) = 63,800 kg
2. Delta IV Heavy (ULA) = 28,790 kg
3. Long March 5 (China) = 25,000 kg
4. Falcon 9 Full Thrust (SpaceX) = 22,800 kg
(Full comparison of all rockets here)

The higher payload capabilities of the Falcon Heavy unlocks various space exploration possibilities that didn’t exist for a long time since the Apollo era. The primary goals with the Falcon Heavy maybe going to the Moon and Mars but the scientist in me is even more excited for the wide variety of science potential from the rocket.

SpaceX Falcon Heavy at the launchpad. Source: SpaceX

A Pluto orbiter and a flyby of Eris

In 2015, NASA’s New Horizons spacecraft gave us the very first high-resolution shots of Pluto and its moon Charon. Before it, no other spacecraft had ever been to Pluto.

Pluto was revealed to be a geologically active world, with vast plains made up of nitrogen ice, a hazy multi-layered atmosphere and mountains as tall as 3 km. There is even some evidence that Pluto hides beneath its surface a vast liquid water ocean.

New Horizons spacecraft view of Pluto’s rugged, icy mountains and flat ice plain. The multiple layers of haze of Pluto’s atmosphere are also seen. Source: NASA

Sadly, New Horizons was a flyby mission that left us with more questions than answers. It wasn’t an orbiter that can continue to send juicy science data from the plutonian system. There are reasons why we haven’t put an orbiter around Pluto yet, one of which has to do with the limitation of the rockets available.

New Horizons weighed 478 kg and was launched on ULA’s Atlas V rocket which is capable of carrying less than 1,000 kg to Pluto. The spacecraft thus couldn’t carry enough fuel that can be used to slow down and get captured in orbit upon reaching Pluto. The Falcon Heavy solves this limitation.

Launch of New Horizons. The Atlas V rocket on the launchpad (left) and lift off from Cape Canaveral (right). Source: Wikipedia

The Falcon Heavy can carry a spacecraft up to 3,500 kg to Pluto. Even if we assume minimal changes to the New Horizons spacecraft, there is more than enough room to carry extra fuel for orbital capture.

Launching even a minimally modified New Horizons-like orbiter to Pluto onboard a Falcon Heavy will give us higher resolution imagery, multiple close passes to Pluto’s moons (including the largest Charon), long term planetary changes and all in all fantastic science.

The Falcon Heavy can also send a flyby mission to the next dwarf planet Eris which is twice as far as Pluto is from the Sun.

Orbiting the ice giants — Uranus and Neptune

It is somewhat of a sad fact that we’ve had orbiters around the gas giants Jupiter & Saturn, but only sent flyby missions to the ice giants Uranus and Neptune. There are a lot of things to know about the ice giants.

Uranus’ weird tilt and a tumbling magnetic field are just some of the mysteries surrounding the planet.

The unusual magnetic field of Uranus, as determined by Voyager 2 during the 1986 flyby. Source: Wikipedia

Neptune on the other hand has mysteries like incomplete ring structure and surprising storms. And its largest moon Triton erupts icy material from its cryovolcanoes.

Global color mosaic of Neptune’s moon Triton taken using the Voyager 2 spacecraft in 1989. Source: NASA. Caption: Me.

Just like the case of a Pluto, the Falcon Heavy can send orbiters to Uranus and Neptune to meticulously study these outer solar system worlds. Their relatively lesser distance compared to Pluto means that the orbiters can have higher quality instruments for the same price.

The fruitfulness of studying ice giants like Uranus/Neptune goes beyond understanding them and their role in the solar system. Have a look at this graph showing the number of exoplanets discovered by type.

A histogram showing the number of exoplanets discovered by each type. The blue bars represent previously verified exoplanets and the orange bars represent Kepler’s newly verified planets as of May 2016. Source: Wikipedia

The category of planets called Sub/Mini-Neptunes are the most common type of planets in the galaxy. Understanding Uranus and Neptune is thus the key to understanding how a giant fraction of all planets form and behave. And the Falcon 9 is well positioned to enable just that.

Light and fast

Being able to send orbiters to Uranus, Neptune and Pluto isn’t the only advantage gained by the existence of Falcon Heavy. The Falcon Heavy can’t just launch heavy payloads, it can also shoot lighter payloads (like most planetary orbiters) into space really, really fast. The time taken to reach these outer solar system worlds can be cut down to 5–8 years instead of the 10–14 years it takes for other existing rockets.

Exploring the moons of Jupiter and Saturn

The relative closeness of Jupiter and Saturn mean that the Falcon Heavy can send far more heavier payloads into their respective systems. Good news is there are already two missions to Jupiter’s moons planned to launch in the 2020s onboard other rockets.

ESAJupiter Icy Moon Explorer (JUICE) will be launched in 2022 and its primary goal is to orbit and study Jupiter’s moon Ganymede and assess its habitability, the only moon in the solar system with a magnetic field. NASA’s Europa Clipper mission will confirm the presence of the likely subsurface ocean on Jupiter’s moon Europa and evaluate the possibilities of Life in it.

An artist’s illustration showing the internal structure of Jupiter’s moon Europa. Beneath the thick ice covering, likely lies an ocean of liquid water caused by the tidal heating effects of Jupiter’s gravity. Source: Source: NASA

The capabilities of the Falcon Heavy could be utilized to add to the science value of these missions. The Falcon Heavy can be used to send not just advanced orbiters, but modestly heavy landers to both Europa and Ganymede due to its larger payload capacity.

An artists’ rendering of NASA’s upcoming mission Europa Clipper passing by Jupiter’s moon Europa. Source: NASA

An orbiter to the Saturn’s geyser erupting moon Enceladus is also an intriguing possibility. Geysers have been detected erupting from Enceladus and the moon is also thought to house a vast ocean of water inside. It is therefore a strong candidate for the presence of Life in the outer solar system, which must be explored.

Cheap and repeatable

The Falcon Heavy is quite cheap for its capabilities, which is SpaceX’s biggest selling point. The fully expendable version costs $ 150 million. For comparison, ULA’s Delta-IV Heavy costs $ 350 million for less than half the payload capacity. The fact that the Falcon Heavy is also reusable (for lighter missions) can substantially lower the cost further. A reusable Falcon Heavy costs $ 90 million.

Falcon Heavy side boosters landing on landing areas LZ1 and LZ2. Source: SpaceX

As the Planetary Society notes, the Falcon 9 is currently certified to launch only relatively lower budget science missions. Faster access and much cheaper launch costs for the either variants of the Falcon Heavy allows multiple such missions to be mounted to these outer solar system worlds.


The cost effectiveness of the Falcon Heavy combined with the faster access to the outer solar system worlds is a substantial change to the way we are used to doing things in space exploration. Science for the win!

If you have been falling in love with images of Jupiter and Saturn from Juno and Cassini respectively, you will fall in love with years worth of outer solar system imagery that the Falcon Heavy can enable.

Pretty excited to see heavy-lift rockets back in the space market. This is truly an exciting time for the space nerd in us.

<![CDATA[Cyanobacteria: The first seed of space colonization?]]>https://blog.jatan.space/p/cyanobacteria-the-first-seed-of-space-colonization-f3b2eccf4b0bhttps://blog.jatan.space/p/cyanobacteria-the-first-seed-of-space-colonization-f3b2eccf4b0bTue, 05 Dec 2017 08:01:10 GMTHere’s a chart that shows the oxygen levels in the Earth’s atmosphere over the past 4 billion years.

Notice something weird? There is practically no oxygen in the Earth’s atmosphere until about 2.5 billions years ago. The oxygen levels in the atmosphere increased dramatically after this period. What led to this Great Oxygenation Event?


Cyanobacteria and their unique history

Cyanobacteria are unicellular bacteria that derive their energy from photosynthesis. They are thought to be the first species to develop the ability to photosynthesize. Generating oxygen as a byproduct of photosynthesis was a game changer that eventually led to the proliferation of multicellular organisms and therefore to animal life on Earth. What’s more, cyanobacteria are the only species to invent photosynthesis in the history of our planet — all plants and algae have derived this ability from them.

A large bloom of cyanobacteria in Lake Atitlán, as seen from space. The lake is in Guatemala, Central America. Source: NASA

Having survived for billions of years and having a wide genetic diversity, cyanobacteria are found almost everywhere, be it on land or in water. They can bloom in ocean water or survive in highly dry deserts. Some species of cyanobacteria even thrive in the Antarctic rocks. Cyanobacteria are extremophiles, meaning they are capable of surviving in extreme environments. Cyanobacteria even survived outside the International Space Station (ISS) for 16 months.

Microorganisms mounted on trays outside the ISS, exposed to the harsh space environment for 16 months. Source: Farunhofer.de

They were mounted on trays outside the ISS, where they were subjected to extreme radiation levels and temperature variations. Not only did they survive for 16 months, they also adapted well to the coldness of vacuum.

The unique mechanisms that cyanobacteria have combined with their extremophile nature have sparked ideas for interesting applications in space exploration.

How cyanobacteria can be used for space settlement

The useful applications of cyanobacteria in space exploration cover a wide range:

  1. Energy source: In the process of photosynthesis, cyanobacteria expel free high energy electrons into the environment, thereby generating electricity from sunlight. Explorations into ways to utilize this electricity by engineering internal photosynthetic pathways of the cyanobacteria are currently on. This could allow for a clean, reliable and efficient energy source for small applications in space missions, where other sources aren’t viable.

  2. Oxygen source: The idea of terraforming Mars using cyanobacteria to generate oxygen in the atmosphere has been thrown out. Carbon dioxide comprises of 96% of the Mars atmosphere. We humans need oxygen to survive and cyanobacteria can convert the ample supply of carbon dioxide into something we can breathe.

  3. Agriculture: The species of cyanobacteria called Microcoleus vaginatusare retain water in soil and prevent erosion. This potentially makes them very handy for farming on custom-engineered alien soils where water wouldn’t be readily available.

All of the world-changing applications (literally!) of cyanobacteria can be realized only if they can reliably work in the hostile environments of outer space. While cyanobacteria have been tested extensively in harsh conditions on Earth across multiple experimental setups, space environments are far more hostile.

Given their genetic diversity, global presence and fundamental importance, cyanobacteria are arguably one of the most — if not the most — successful species on Earth. If they live up to even some of this potential, we may be able to make the leap to an interplanetary species. The baby steps start right now, the next of which is to see how cyanobacteria react to and photosynthesize in extreme space environments such as on the Moon, Mars, and beyond.