NASA tries to keep an asteroid mission in the bagby Jeff Foust
|
| “If you do not have a high-power solar electric propulsion capability, the asteroid redirect mission, at least as how we’ve sketched it out, couldn’t be done,” said Reuther. |
ARM, though, effectively reversed the mission architecture: instead of sending astronauts to a distant asteroid, it would bring an asteroid to the astronauts. A robotic spacecraft would go out to a small asteroid, likely no more than 10 meters across, and nudge it enough to bring it into a “distant retrograde” orbit around the Moon. Astronauts could then visit it on a relatively short—about 20 to 25 days—mission using an Orion and SLS.
The ARM concept, though, has been a difficult sell. There has been something of a “snicker factor” associated with the concept of moving an asteroid into cislunar space, including elements of the mission architecture where the asteroid would be wrapped in a giant bag, to be unwrapped later by visiting astronauts as if they were opening a birthday present. Scientists have questioned the scientific utility of such a mission, and both NASA authorization and spending bills currently in House would block funding for the ARM (see “Science and the ARM”, The Space Review, July 15, 2013).
The latest milestone in NASA’s efforts to better develop—and built support for—the ARM concept is this week. NASA is hosting an “Asteroid Initiative Idea Synthesis Workshop” starting Monday afternoon through Wednesday in Houston, featuring participants who submitted papers under a NASA request for information earlier this summer. “The purpose of this workshop is to further examine and foster a broad discussion on these newest ideas and help inform NASA’s planning activities,” the event website states. (One complication not mentioned is the threat of a government shutdown starting Tuesday; while a NASA event, it’s being held off the campus of the Johnson Space Center.)
In a panel session and later press conference at the AIAA Space 2013 conference earlier this month in San Diego, NASA officials said the idea synthesis workshop this week would guide their future planning for the ARM. “We’re going to factor all of that discussion into our thinking,” said Bill Gerstenmaier, NASA associate administrator for human exploration and operations.
One key issue is exactly what kind of asteroid the ARM would seek to redirect. While the nominal mission has been to find a small asteroid, no more than 10 meters across, and redirect it toward cislunar space, NASA officials said over the summer they were considering an alternative approach where the robotic spacecraft visits a larger asteroid, plucks a boulder of desired size off its surface, and brings that to cislunar space.
“There’s some advantages and disadvantages of both,” Gerstenmaier said. A systems integration team within NASA will weigh those advantages and disadvantages, incorporating any insights from this week’s workshop as well. “Then we’ll decide, probably by the end of the year, which way we want to go forward.”
He emphasized that, at this early stage of the program, they were trying to be as open as possible to any alternative mission concepts. “This is a unique opportunity, like an early requirements phase,” to trade various options and pick a mission design, he said.
| “We have to start talking about this as something that’s very exciting,” he said. “Think of this as really pushing human presence into deep space, beyond low Earth orbit,” said Gerstenmaier. |
Gerstenmaier and others at NASA have continued to sell the ARM on the various benefits they believe it offers to science, exploration, and technology development. “It improves our asteroid detection capability,” Gerstenmaier said, focusing new resources on the ability to detect more, and smaller, near Earth asteroids. “It pushes solar electric propulsion technology, which has lots of applications for us in the future and moves us forward. And, lastly, it provides an extremely interesting target for crews to go to.”
NASA is particularly emphasizing the use of solar electric propulsion (SEP), a technology the agency was already interested in developing and which it believes is particularly well-suited for the ARM. “With the Space Technology Mission Directorate, we were already looking for ways to demonstrate high-power solar electric propulsion,” said James Reuther, deputy associate administrator for programs within that directorate. The ARM, he said, “an excellent fit” for SEP in terms of the power needed and the available technologies. “If you do not have a high-power solar electric propulsion capability, the asteroid redirect mission, at least as how we’ve sketched it out, couldn’t be done.”
NASA also hopes this week’s workshop will help develop ways to improve outreach and better communicate the mission’s potential benefits. JPL chief engineer Brian Muirhead said they’ve taken advantage of some non-traditional outreach methods, including a Google hangout and an “Ask Me Anything” question-and-answer session on Reddit.
Gerstenmaier urged attendees of a luncheon panel session at Space 2013—representing a cross-section of the space industry but a tiny slice of the general public—to reach out beyond the industry’s narrow confines to help communicate the ARM’s potential benefits. “We have to start talking about this as something that’s very exciting,” he said. “Think of this as really pushing human presence into deep space, beyond low Earth orbit. It enables lunar activity, potentially, in the future. This is a way for us to start breaking the ties and getting beyond low Earth orbit. I think it’s a pretty compelling mission if we look at that way.”
| “We’re really good at picking dates and destinations, but then that’s hard in this budget environment to pull that off,” Gerstenmaier said. “This is a slightly different way of thinking of things.” |
One group that likely needs additional work to be convinced of the ARM’s “compelling” nature is Congress, particularly members of the House that expressed opposition to the ARM this summer. “We’re starting to have those discussions in Washington,” Gerstenmaier said, emphasizing the benefits for human exploration beyond the visit to the captured asteroid itself, such as learning to make use of lunar gravity assists and testing spacewalking capabilities far beyond Earth orbit. “These are things we’re going to have to get comfortable with if we’re ever going to be able to do a long-term asteroid mission, or if we’re going to Mars. These are things we have to learn, and this mission gives us a reason to go do that.”
One challenge to winning Congressional support, he suggested, is that this capability-driven approach is a different way to do space exploration than destination-driven approaches used in the past. “We’re really good at picking dates and destinations, but then that’s hard in this budget environment to pull that off,” he said. “This is a slightly different way of thinking of things, but it takes a little bit of extra thought to do that, so we need some extra time to work with our Congressional stakeholders to describe to them what we’re doing and show that this has merits.”
In that context, Gerstenmaier said, ARM should be seen not as a standalone mission but part of that broader exploration context. “This is a way to put together our capabilities and do something that real and tangible, but it’s not just a one-time thing. It actually feeds forward into the broader context of what we want to do with humans in space.” How well NASA and supporters of the ARM concept can communicate that message—of ARM developing the capabilities needed for the future of human space exploation—may become the biggest factor in whether the concept can secure support from a skeptical Congress and befuddled general public.
