Bush's former NASA Administrator Michael Griffin says Obama's Space Launch System 'next essential step': guest opinion

By Dr. Michael Griffin and Daniel Dumbacher

Dr. Michael Griffin is a former NASA Administrator (2005-2009) under President George W. Bush and Daniel Dumbacher is a former NASA Deputy Associate Administrator for Human Exploration and Operations.

In issuing its "National Space Policy" in 2010, the Obama Administration stressed that in our modern society, "we find ourselves in a world where the benefits of space permeate almost every facet of our lives."

Our mastery of space has expanded our frontiers, advanced science, created new markets, helped save lives by warning of natural disasters, made agriculture and other resource management more efficient, and provided global access to advanced medicine, broadband Internet and other life-changing technologies.

The Administration wisely charted two continuing missions for the U.S. space community - deep space discovery and exploration and a pivotal human mission to Mars.

Both these missions require major technological leaps, however, including above all a new rocket with the enormous heavy-lift and deep space launch capability required to safely and effectively propel a vehicle further into our solar system than ever before.

NASA has taken up this call, and is working diligently on the powerful new launcher needed to go further into space called the Space Launch System (SLS) - which will have the highest thrust system and largest payload capacity ever developed.

When complete, SLS will launch more than twice the payload mass and 6 times the payload volume of any other American rocket. It will provide approximately 10 percent more lift than the Saturn V - the only other rocket ever launched able to carry humans beyond the orbit of the earth.

A larger rocket means fewer launches and less risk to our astronauts, since launch is one of the most challenging aspects of any mission.  It also drives down cost by reducing the number of missions needed to get a full complement of mission components into space.

A Mars mission, for example, will require a heavy lander, in-space structures, food, water, and fuel, and other bulky components. NASA planners believe SLS can accomplish this with 6 or 7 launches, while existing rockets would require approximately 30 missions.  It's the difference between loading a large moving van or driving multiple trips in a passenger car.

The SLS also allows for faster transit times to deep space locations, reducing mission cost and allowing us to do more at our destination. For example, SLS can reach Jupiter's moon Europa - one of NASA's highest priority destinations due to the life-holding possibilities of its icy global ocean - in half the time of other launch vehicles.

The SLS vehicle design materialized from an extensive, unbiased set of NASA technical studies which compared all possible scenarios, with a focus on efficiency and budget constraints.

Other solutions external to NASA were also solicited. Among the factors driving the selection of the 130 metric ton SLS design were human exploration requirements, the state of propulsion technology, the health and capability of the industrial base, and the budget outlook.

The chosen propulsion system for the SLS is based on the Space Shuttle, proven technology with a proud history and demonstrated performance and reliability.  And, contrary to some suggestions, SLS launches will cost no more than existing commercial U.S. systems - which are currently advertised at about $4.5 million per ton of payload.

Current U.S. Space Policy represents a pragmatic and cost-effective approach to meeting our deep-space exploration needs. Continued development of the SLS allows NASA the capability to focus on a variety of missions needed to explore space, advance our knowledge of our solar system, learn more about the history of our own planet, and inspire future generations.

As we reflect upon, and celebrate, both the first human lunar landing 46 years ago and the more recent successful Orion flight test, it is important to focus on the path forward for human space exploration. That path is best followed by developing the fully capable version of the SLS.