Today, for the first time in a while, I was able to do something that's become one of my favorite parts of living in Boston -- walk down the Esplanade, across the Massachusetts Avenue Bridge, and over to MIT for an Aero/Astro event! The trees along the riverfront were full of buds and tiny leaves, and the wind was carrying cherry blossom and magnolia petals along the walking path as I made my way to the bridge. It was the kind of lovely spring day that can't help but put you in a good mood, even if you aren't going to an exciting presentation.
I was very excited because the presentation in question was being given by MIT alum Dr. Nicholas Patrick, the astronaut whose previous presentation I'd seen -- and really enjoyed -- back in October. I recognized Dr. Patrick as I entered the room and found a seat in the front row, and, to my great surprise, he recognized me and told me he'd liked my blog post about his other presentation!
Somehow I managed to keep my cool and reply "Thank you!" politely instead of freaking out because an astronaut had complimented my blog.
Now even more excited, I got out my pencil and notebook and got ready for the presentation to begin. Dr. Patrick began his talk with a very surprising pie chart of how he'd spent his time as an astronaut since being selected by NASA in 1998. It turned out that the time he'd actually spent flying in space -- his two missions to the International Space Station and the spacewalks he'd described so lovingly in his last presentation -- had accounted for only .6 percent of his total time as an astronaut! However, the way he spent 1/3rd of his time, and the subject of today's presentation, was something he found just as satisfying -- engineering.
Dr. Patrick's specialty is Human Factors Engineering, or designing a vehicle to be safe and comfortable for its occupants. Before becoming an astronaut, he did this for Boeing, helping design better cockpits for commercial airliners. Today, he's still working on designing cockpits, but for a much more far-out vehicle -- NASA's next-generation Orion space capsule. (My eternal spacecraft crush.)
In a recent test, Dr. Patrick and his co-workers watched as a test version of the Orion capsule was exposed to 185 decibels of sound energy to simulate the vibrations a real capsule would encounter in an abort scenario. The door to the test chamber was filled with 20 tons of sand to dampen the noise, but even so, Dr. Patrick said the sound he heard was like being launched in the space shuttle all over again!
The Orion spacecraft will be able to be used for missions to many different destinations -- the Moon, Near-Earth Asteroids, and even hopefully Mars someday, but one possible destination is a bit less tangible.
Lagrange points are places around two bodies in space -- be they stars, planets, moons, anything -- where the gravity of the objects cancels each other out, creating special spots where a spacecraft can be "parked" and stay in place without using a lot of fuel. (The James Webb Space Telescope will be headed to L2, the second of the Lagrange points created by the gravity of the sun and the Earth.) A satellite or space station parked at a Lagrange point would remain there for a long time and could be a staging base or service station for missions headed further out.
But, of course, like walking into Mordor, one does not simply fly off to a Lagrange point -- or to anywhere in space at all. There are a lot of challenges involved in the design of any spacecraft, and Dr. Patrick was there to discuss a few of them with us.
Some of those challenges have to do with the way the human body adapts to being in space. Bones and muscles tend to become weak after a long time in microgravity, but by exercising an hour a day with the Advanced Resistance Exercise Device, astronauts on the space station have been able to come back to Earth after six months with minimal damage. In fact, Dr. Patrick told us, they sometimes come back with BETTER musculature because of these workouts.
But some aspects of adapting to microgravity are a bit more subtle and harder to conquer. Being weightless after a lifetime in Earth-normal gravity confuses astronauts' inner ears, sometimes making it difficult to walk straight for a few days after returning to Earth. Psychologically, getting used to the idea of moving in three dimensions is a challenge as well -- we're used to moving with the floor under our feet, but in space, it can be quicker to push off one wall and simply "fly" across a room than to crawl along the walls to get there.
Other challenges involve the unique environments of deep-space destinations beyond Earth orbit, such as guarding against radiation outside of the Earth's protective magnetic field. We've all heard distances in space measured in light-years because those distances are so big that it takes light -- just about the fastest thing there is -- years and years to cross those distances. Distances within our solar system are measured in smaller light-minutes and light-hours, but that still means that radio signals sent from a spacecraft near Mars will take at least several minutes to reach Earth, and just as long for a reply from Mission Control to come back. Not an ideal situation if you're asking Houston for help with solving a problem.
Of course, there are also lesser problems to deal with in spacecraft design, like making the controls intuitive and easy-to-use. Making sure pilots can see all of the necessary displays, even when wearing space helmets, and minimizing the number of switches and buttons whose locations need to be remembered are also part of Dr. Patrick's job. Given how important all of this work is, I can see why he considers it just as satisfying as flying in space!
When the time for questions came after Dr. Patrick's presentation, I was still thinking of what he'd said about astronauts learning to think and move in three dimensions. I asked him if he thought there were any ways people could get into the habit of thinking in three dimensions while still on Earth to prepare. Doing gymnastics? Spending a lot of time maneuvering underwater with scuba gear?
"If you were living in a monkey habitat, where you could climb on bars to get everywhere, then you could adapt to it. Living in a building with glass floors would help, as well."
Hmmm... something to consider. He also told us that one simulator for steering a vehicle in weightlessness uses a room with an air-bearing floor where the vehicle "flies" a fraction of an inch off the ground on a column of compressed air.
"So it's like being the puck on an air hockey table?" I asked.
"It's exactly like being the puck on an air hockey table." He told me.
As if I needed another reason to visit Houston ...