NASA's first spacewalk, during the Gemini IV mission of 1965, came uncomfortably close to losing an astronaut. Ed White, stepping out into the abyss, found himself overcome with the joy that is sometimes referred to, fittingly, as "space euphoria." Floating in space was "the most natural feeling," he enthused to James McDivitt, the mission commander who was orchestrating White's walk from inside the Gemini capsule. White felt "just like a million dollars," he continued. "I've ... it's just tremendous."
White may have relished that first step into space a little too much, though. After 20 minutes of out-of-this-world bliss, the giddy star-sailor got a message from Ground Control: it was time for him to return to his ship. And White ... refused. "Aw, Cape," he said, "let me just [take] a few pictures." After several minutes of back-and-forth -- Cape insisting, White resisting ("you almost could not drag me in," he admitted) -- Ed White finally, reluctantly, and belatedly began his return to the space capsule that was his only ticket back to Earth. It was, the astronaut would sigh, "the saddest moment of my life."
The scariest moment of Ed White's life, however, likely came within the next half hour. Because it ended up taking him 25 minutes to get back into the Gemini capsule. The craft's hatch experienced mechanical problems that made the door difficult to open and latch. And White's bulky spacesuit, all the while, was quickly losing its ability to protect its frail occupant from the surrounding void. The astronaut was using up his oxygen, rapidly. And here was the catch: if White should run out of air -- or, for that matter, if he should lose consciousness for any other reason while out in space -- McDivitt was under orders to cut him loose "rather than risk his own life trying to wrestle White back." Ed White's dreamy sojourn could have become, with a mission-saving snip of a tether, a nightmare.
Marshmallow Men on the Moon
We've come a long way since then. Spacewalks are now, of course, a regular occurrence. We've developed spacesuits that don't require their wearers to sacrifice themselves to the abyss should something go wrong during an EVA. Today's suits, unlike White's, are equipped with jetpacks that arm their wearers with thrusting power -- just enough to get them back to their ship or station should their tether become ... untethered. It's been a long time, thankfully, since an umbilical cord was an astronaut's only connection back to Mother Earth.
And yet spacesuits -- intricate spaceships made for a party of one -- are, like everything else NASA does, a work in progress. They are, despite the advances we've made in their design, notoriously unwieldy. They are rigid. They are bulky. They are heavy -- 310 pounds, not including their occupant, when in gravity. And they are, with their internal insulation and their external packs and their gloves that are more like mittens, really, really hard to maneuver. The suits are certainly effective at their primary jobs: keeping astronauts alive in space's void. They're much less effective, however, at letting astronauts act as explorers and wanderers and scientists and athletes. They're much less effective at letting astronauts be, you know, astronauts. NASA sums it up nicely: "These suits are officially known as EMUs -- extravehicular mobility units -- but they allow only limited mobility."
That is, however, soon to change. Draper Laboratory, an 80-year-old R&D lab, has been working with MIT and NASA's Johnson Space Center to develop a suit that will function, essentially, like a body-molded version of a traditional spaceship. Instead of floating in free space, at the mercy of forces acting on it, the suit would be able to move on its own. The Draper/MIT/NASA team is getting ready to share the results of its research with the AIAA, and they provided me with an early copy of the paper they'll present.
The suits Draper's collective has designed feature, like the current versions, jetpacks. But their jetpacks are much more powerful than the contingency versions that currently propel spacesuits. The current pack is known, in groan-worthy NASAese, as the Simplified Aid for EVA Rescue (that's right: the SAFER). It's designed specifically and narrowly for "propulsive self-rescue" in emergencies that find an astronaut untethered from his or her spacecraft. But SAFER is not, you know, always better. Its jetpack will give you some forward thrust; it won't let you do much steering.
The suit Draper is prototyping wants to change that. It makes strategic use of gyroscopes (specifically, control moment gyroscopes, or CMGs) -- which, says Bobby Cohanim, Draper's Mission Design Group leader, will be able to "keep the astronauts stable by adding attitude control to offset torques and forces and increase range of motion."
That stability is crucial. Because the future spacesuit is actually, in Draper's vision, a "next-generation maneuvering and stability system" -- one that "incorporates control concepts optimized to support astronaut tasks." The lab is trying to turn spacesuits, basically, into workspaces. It imagines a future in which astronauts will fly, rather than float, in space.
And that's because that future will likely involve the exploration of near-Earth asteroids and (fingers crossed!) Martian moons. It's a future that will require humans to do work in zero-gravity and, more likely, microgravity. In those environments, tasks that would be simple on Earth -- hammering, digging, screwdriving -- are potential sources of danger. A torquey twist of the wrench as you're making a spaceship repair could keep you perpetually rotating, whirling away from your craft. On an asteroid, a dig of a shovel could push you away from the surface you're excavating.
And gravity would not be there to pull you back in.
Without a pilotable suit, in other words, future astronauts could face the fate that almost befell Ed White: ending their lives alone, severed, in space.
Segway to the Stars
The notion of using gyroscopes in spacesuits, Kevin Duda, Draper's principal investigator in the spacesuit project, told me, dates as far back as the early 1970s -- to the Astronaut Maneuvering Equipment experiment done with Skylab. "They had something similar to what we're proposing for the EVA suit," Duda notes.
Then came the thruster-focused jetpacks, first space-tested in 1984 by the astronaut Bruce McCandless. Then came the SAFER devices, first used in 1994. Today, NASA is developing an iteration of the SAFER concept: a maneuvering unit that will allow astronauts to make external spaceship and space station repairs in hard-to-reach areas. That device, the Draper team notes, has obvious applications for EVA tasks near the surface of low-gravity objects: The modified jetpack could, ostensibly, be used on the surface of an asteroid or a moon.
But it wouldn't be ideal. "Since these devices were mainly designed for approaching and capturing satellites, or for rescue maneuvers in the case of the SAFER," the researchers write in their paper, "maintaining rigid attitude control to provide a stable work platform was not a design requirement. However, when EVA astronauts are attempting to perform tasks that require precise motor control such as sample collection and equipment placement near the surface of an asteroid or a Martian moon, the current control system will fire thrusters to compensate for the resulting changes in center-of-mass location and moments of inertia, adversely affecting task performance."
The gyroscope-leveraging suit, on the other hand, would offer the astronaut wearing it more finely tuned control over his or her movements. It would create an environment that would be, ever-so-slightly, closer to what astronauts are used to on Earth. Plus, the team points out, CMGs consume no propellant, meaning an overall reduction in fuel consumption during missions that involve astronauts doing work in free space. "Given sufficient electrical energy storage, using CMGs rather than thrusters for attitude control will extend the useful time of device operations between refueling."
Which is all a way of saying: The team has designed a celestial Segway. Except this particular gyroscope-leveraging vehicle involves space-tailored jetpacks.
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