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Matthew Gast, EVA Trainer
November 13, 2008


From the earliest preparations until astronauts are actually working in the vacuum of space, a lot of effort goes into a spacewalk. Matthew Gast of NASA's Johnson Space Center assists astronauts through the entire process, from their first spacewalk training, to writing the job descriptions that they will do in space, to monitoring the work as it's done.

What is your job, and how do you support spacewalks?
I work in the Mission Operations Directorate at NASA's Johnson Space Center in Houston. I am responsible for training astronaut crews, both generic and mission-specific training, and then executing those missions within Mission Control. Within mission operations, I work in the extravehicular activities, or EVA, office. EVA is the term used by NASA to refer to spacewalks. I have a number of primary jobs in the EVA office: an instructor, a mission designer and a flight controller in Mission Control.

Instruction is divided into generic and mission-specific training. Generic training begins when the astronauts are brand new. We mentor and instruct them through a program we call "EVA Skills" at NASA's Neutral Buoyancy Laboratory. Here they learn how to work efficiently in the spacesuit in an environment that simulates, underwater, the weightlessness of space. Typically, an astronaut will go through 10 to 15, six-hour underwater training sessions in the spacesuit, developing the skills necessary to effectively work as an EVA crew member in orbit. Upon completion of the skills program, qualified astronauts are then eligible for flight assignment as an EVA crew member.

Here our duties shift, and we become mission designers. Taking the requirements from the entire EVA community, we develop procedures that allow us to accomplish the tasks associated with a specific mission, whether it is a satellite deployment, repair of the Hubble Space Telescope, or continued construction of the International Space Station. We begin with a basic procedure. We refine it by training the assigned astronauts to perform the tasks. In most cases, we go from initial plan development, to crew training, to flight within 12 to 16 months.

Finally, when the mission launches, we work as flight controllers in Mission Control. As EVA flight controllers, we support the crew from the ground. We provide technical insight and guidance, and respond to crew questions and any EVA-related problems that should arise.

Why is this element of spacewalk support important?
With respect to training, it is essential to provide the astronauts with the best possible training, not only for the success of the mission, but also the safety of the astronauts. One can think of the spacesuit as a portable spaceship. Each time the astronauts walk in space, there is risk involved. Through training, however, we are able to lessen those risks. Astronauts are highly-trained and adept at dealing with contingencies. The ability to resolve any unforeseen issues is the number one key to our success, time and again.

Regarding our support in Mission Control, we provide a level of technical expertise beyond the capacity of the crew. Even when everything is going well, we oversee the process to ensure nothing is skipped. Much like overhauling an engine is useless if you forget to reconnect the spark plugs before trying to start the car, each added piece of hardware will not function properly unless every step in the assembly procedure is completed.

As the developers of those procedures, we are able to watch over the crew to ensure everything is completed as required. When things do not go according to plan, we are responsible for quickly finding a resolution. We work with the entire EVA community - hardware designers, tool designers, safety officers, etc. - to quickly develop a course of action that solves any problem facing the astronauts outside. Like scuba divers, EVA astronauts do not possess an unlimited supply of air. Time is always of the essence. Quick resolution often means the difference between success and failure.

How did you get your current position?
I came to NASA straight out of college from the University of Minnesota in 1999. I began my career in mission operations' Flight Activities Office. I was in charge of designing and planning space shuttle missions to achieve all requirements. Through interactions both professionally and personally, I learned of the EVA office. As I learned more about EVA, I discovered that the job was a fit for me and had the fortunate opportunity to move to the EVA office in the summer of 2005. Once here, I became heavily involved in the skills program, training new astronauts in the intricacies of spacewalking. I now work as the lead of the skills program.

Were you involved with NASA as a student in high school or college, and, if so, in what projects were you involved?
I was not involved with NASA on any professional level before coming to work at the Johnson Space Center. On a personal level, I began flying at the age of 16 and have always had a resonating interest in aviation and space. That interest is what brought me to NASA.

What are the challenges your team faces in working with this aspect of spacewalks?
The challenges facing the EVA office revolve most significantly around the construction of the International Space Station. Construction is in full swing, and the development of the procedures must keep pace with the rapidity of shuttle flights. The space station is in a state of growth. New modules are being added, and the international partners are becoming more involved. That makes integrating the mission and hardware requirements - including those for the modules from the international partners - into the procedures that much more challenging.

As NASA prepares to go back to the moon, what changes will be needed for this aspect of spacewalk support?
In preparation for the moon and the retirement of the space shuttle, EVA will see numerous changes. At this time, we spend a portion of our time training the crews on contingency tasks associated with the space shuttle. With retirement (of the shuttle), those training objectives will be obsolete, but the new vehicle will bring its own set of contingencies that must be trained for.

More significantly, however, will be the changes in the primary mission objectives. The environment is the same for space station construction or Hubble Space Telescope repair. But for lunar - and eventually Martian - extravehicular activities, the premise will be very different. Rather than focusing on a weightless environment, we will deal with reduced gravity, as on the lunar surface. Our objectives will change from station construction to lunar habitat construction and lunar geology.

Significant changes will also come in our training facilities. The Neutral Buoyancy Laboratory offers an excellent way for crews to train in a weightless environment. But in a reduced-gravity environment, we will need to develop a training facility. The new facility will need to allow crew members, wearing spacesuits, to manipulate terrain that simulates the lunar surface. In moving to EVA training for the surface of Mars, new challenges, such as traversing in extreme winds, will need to be resolved. To keep pace with the coming evolution in EVA will require problem-solvers who are not daunted by seemingly insurmountable challenges.

What else would you want to tell people about your job or your experiences with spacewalk support?
Being a part of the EVA team at NASA has been an incredible experience. The work places you at the forefront of everything NASA is doing in human spaceflight. The people you work alongside are the most talented and dedicated I have ever had the privilege to work with. Each day brings a new set of challenges that require resolution and a new opportunity to face those challenges head-on and find a solution. While not everyone can experience an actual EVA firsthand, it is incredibly satisfying to be a small part of what it takes to make an actual EVA - like the solar array repair on STS-120 - successful.

Related Resources
NASA's Johnson Space Center
NASA's Neutral Buoyancy Laboratory

David Hitt and Heather R. Smith/NASA Educational Technology Services


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Gast wearing a spacesuit underwater
Part of Matthew Gast's responsibility as a spacewalk trainer is to work with astronauts underwater in the Neutral Buoyancy Lab. To better understand the challenges of a spacewalk and to design better training sessions, Gast trains underwater in the EVA spacesuit, just like the astronauts do.
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Matthew Gast
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