NASA is full steam ahead in the development of its asteroid retrieval mission.NASA isn’t exactly the Federation of Star Trek. But in their asteroid-snatch pitch last week to attendees of the American Institute of Aeronautics and Astronautics’ Space 2013 Conference, NASA associate administrator William Gerstenmaier (Human Exploration and Operations Mission Directorate) and his colleagues sure struck a Trekkie note — with epic music to boot. In sum? They want to boldly go where no one has gone before.
The space agency’s asteroid retrieval mission surprised a fair number of folks when announced in April. But despite ongoing Congressional budget stalemates, the NASA team was upbeat.
“People are always dreaming about doing bold and different things and exploring different worlds,” deputy director of engineering Steve Stich (NASA Johnson Space Center) said during a press conference later that afternoon. “Going to an asteroid is something we’ve never done.”
The basic mission concept has three components. One, search for small near-Earth asteroids that would be good targets. Two, send a robotic spacecraft to rendezvous with one of these asteroids, bag it, and drag it back to lunar orbit. Three, fly a crew out on the future Orion capsule to check it out.
The second two segments combined would take five years: 1.5 years for the robotic craft to reach the asteroid, three years to tow it back, and about 26 days for the roundtrip human visit. The asteroid’s orbit would be stable for 100 years, said Paul Chodas (NASA Near-Earth Object program), so there would be plenty of time for follow-up visits before sending the rock home.But the details of the asteroid-snatching scheme are still fuzzy. Mission planners don’t have a target yet; in fact, they’re still deciding whether to grab the 7- to 10-meter asteroid originally envisioned or instead pluck a boulder off a larger asteroid, such as Itokawa. Another idea suggested by William Bottke (Southwest Research Institute) and his colleagues is to target mini-moons, small asteroids that Earth temporarily snags as satellites. Earth picks up these bodies near two of the Sun-Earth system’s shallow gravitational wells, called Lagrangian points. Simulations suggest these bodies are fairly common, so mini-moons could be straightforward objects to target. The mini-moon suggestion is one of 96 mission-related ideas that will be considered at a workshop at month’s end. (You can read the abstracts on the workshop website.)
Gerstenmaier said they hope to have the game plan finalized by next February. Once they do, they can nail down the cost — which has a current ballpark estimate (sans launch vehicle) of $1 billion.
NASA is doing everything it can to keep costs at a minimum, especially given the climate in Congress right now. A lot of that effort manifests as pooling existing resources and research efforts from across the agency, from propulsion technology development (the robotic craft will use a ramped-up version of the Dawn spacecraft’s solar electric propulsion system) to the crew’s spacesuit design.
The agency is also pulling in science missions. WISE is being roused to help look for near-Earth asteroids, and Spitzer will join in to study two potential targets next year, Chodas said.
Gerstenmaier repeatedly stressed that the asteroid retrieval mission is not a destination mission. He summed the initiative into three points:
- Improves near-Earth asteroid detection: hunting for targets will allow NASA to spend time and money finding the smaller objects it normally wouldn’t look for.
- Pushes technology development: NASA will need solar electric propulsion (and associated solar cell array advancements) for future exploration, and this mission is exactly what the agency needs as a good demo case for the technology, said James Reuther (NASA Space Technology Mission Directorate).
- Provides a stepping stone for moving humans to deep space: if humans are ever to go to Mars, we’ll have to venture to places where it takes more than a few hours to come home. Plus, an asteroid will take advantage of humans’ ability to adapt to unexpected situations — astronauts won’t be quite sure what they’ll find inside the bag until they open it.
While good science might come out of the mission, that’s not the focus. It’s about pushing ourselves to the next level.
“You need to turn off that logical side of your brain, and you need to turn on that emotional touchy-feely side, the one you never use,” Gerstenmaier said. Jump up and down a few times, even pull out the breakdancing if you can (yes, he actually said that), and get your friends excited about this mission. “We’re gonna go grab a rock and move it here.”