Soyuz MS-17 completes Ultrafast 3 hour journey to ISS

The three space travelers of the Soyuz MS-17 mission launched on a six-month mission the International Space Station.

Soyuz MS-17 lifted off on a Soyuz 2.1a booster from the Baikonur Cosmodrome, Site No. 31/6, in Kazakhstan at 05:45:04 UTC on 14 October (01:45:04 EDT), lofting its international crew to space for a very fast, two orbit, three hour rendezvous with Station.

Ultrafast rendezvous method:

The launch marked a milestone for a crewed Soyuz spacecraft, being the first to use a new “ultrafast” rendezvous” scheme with the ISS. Following a flawless ascent to the correct orbit, Soyuz MS-17 caught up with the orbiting laboratory in only two orbits (three hours), halving the time it takes for crew to get to the Station.

This method takes over from the previous one that saw the Soyuz spacecraft spend four orbits in free-flight to catch up with the ISS in approximately six hours. That method, which was first used with crew on Soyuz TMA-08M in March 2013, took over from an even older method where the Soyuz would complete 34 orbits before arriving at the ISS, leaving the crew inside the small spacecraft for over two days.

Although Soyuz MS-17 marked the first crewed mission to use the ultrafast method, it has been tested before using un-crewed Progress resupply spacecraft. Multiple Progress have successfully utilized the two-orbit, three hour rendezvous profile, starting with Progress MS-09 in July 2018.

Soyuz MS-17 during rollout to Site No. 31/6 at Baikonur. (Credit: Roscosmos)

Unfortunately, something as simple as a slightly off-nominal orbital insertion or missed correction burn could dash ultrafast rendezvous.

In March 2014, Soyuz TMA-12M launched with the intention of bringing its three crew members to the ISS using the then-new six-hour rendezvous method. However, an issue with the Soyuz’s attitude control system caused the spacecraft to miss its third scheduled course correction burn, necessitating a reversion to the two-day rendezvous plan.

The need to have Soyuz crews arrive at the Station so quickly has to do with the extremely cramped, close-quarters nature of the vehicle. For the crew inside, it is a far better psychological and physical benefit to reach the Station as quickly as possible.  However, it is perfectly safe for crews to be in Soyuz for a two day trip to the Station should that be needed.

Conversely, the U.S. Commercial Crew vehicles, Dragon and Starliner, while theoretically capable of reaching the Station that quickly, do not have that same requirement as they are far roomier for their four passengers given they are not solely ISS rotation vehicles but available for solo missions to Earth orbit as well.

Therefore, the U.S. vehicles target/will target a more leisurely one-day rendezvous flight profile with the Station — as was seen on SpaceX’s Demo-1 and Demo-2 missions and is the plan for Crew-1 in November and Starliner’s Orbital Flight Test 2 mission in 2021.

The Mission:

Due to the COVID-19 pandemic which has been sweeping the planet since November 2019, extra precautions were needed as the crew prepared for their journey to the Station. Similar precautions were used prior to the launch of Soyuz MS-16 and SpaceX’s historic Demo-2 mission, both of which left the planet amid the pandemic.

Rubins, Ryzhikov and Kud-Sverchkov (L-R) wearing protective face masks in front of their spacecraft, October 2020. (Credit: NASA/Roscosmos)

Roscosmos trained a two member reserve crew (in addition to each back-up) to add extra precaution and insure launch occurred on time even if any member of the prime or backup crew falls sick. Russian cosmonauts Anton Shkaplerov and Andrei Babkin took the positions of Reserve Commander and Flight Engineer 1 respectively, while NASA opted not to assign a reserve to Rubins and Vande Hei.

The launch placed Soyuz MS-17 into its initial orbit, where the craft then separated, deployed its solar arrays and communication antennas, and when immediately sent its position and velocity data back to Mission Control, Moscow, to verify a good orbit insertion and ability to perform the ultrafast rendezvous.

With that data confirmed, the crew arrived at the ISS in approximately 3 hours and 12 minutes, where they docked to the Rassvet docking port at 08:48 UTC (04:48 EDT).  Once docked, they will join Expedition 63 crew members Chris Cassidy, Anatoli Ivanishin, and Ivan Vagner, who have occupied the station since April this year and are scheduled to depart later this month.

As members of Expedition 64, they are scheduled to be joined by SpaceX Crew-1, the first operational crew rotation flight of SpaceX’s Crew Dragon and NASA’s Commercial Crew Program. The flight will ferry NASA astronauts Michael Hopkins, Victor Glover, and Shannon Walker as well as Japanese astronaut Soichi Noguchi to the ISS for a six month stay.

Crew-1 was originally scheduled to join Expedition 64 at the end of October; however, an issue with a SpaceX Falcon 9 rocket’s gas generators during a September non-NASA launch has caused a delay to no earlier than “early- to mid-November”.

Walker, Glover, Hopkins and Noguchi (L-R) during Dragon training for Crew-1. (Credit: NASA)

During the course of Expedition 64, Ryzhikov and Kud-Sverchkov are scheduled to perform two spacewalks, the first to carry out routine maintenance on the Russian segment and a second to prepare the Pirs docking compartment for separation, as the module is scheduled to vacate the Station in early 2021 to make way for the arrival of the long-delayed Nauka laboratory module.

Soyuz MS-17 and its three crew members are scheduled to leave the ISS in April 2021 ahead of a return to the Kazakh Steppe, with a total planned flight time of 177 days.