’s 2013 Asteroid Initiative Idea Synthesis Workshop produced nearly 30 recommendations for refining strategies to identify, capture and maneuver a seven- to 10-meter near-Earth object into lunar orbit for a visit by astronauts.
The proposed undertaking has emerged from its first U.S. budget cycle, but is still in search of significant U.S. Congressional and international backing.
The recommendations—outlined in aworkshop report released Jan. 30—range from soliciting deeper U.N. engagement in the identification of asteroids that pose a potential impact threat to Earth and forging public/private partnerships to carry out the initiative, to enhancements of NASA’s Orion crew vehicle with an augmentation module for deep-space missions and demonstrations of deflection techniques for much larger asteroids.
The advice was drawn from two workshop sessions held at the Lunar and Planetary Institute in Houston: a Sept. 30 gathering interruped by the federal government shutdown, and a Nov. 20-22 session. The workshop was hosted in response to a June request for information (RFI) from NASA on its proposed Asteroid Redirect Mission (ARM) and Asteroid Grand Challenge (AGC) — coupled initiatives to launch U.S. astronauts to a lunar orbiting asteroid using Orion and Space Launch System heavy-lift rocket hardware as soon as 2021, while demonstrating technologies for deflecting a potential impactor capable of global or regional devastation.
The RFI, open to individuals, other government agencies, the private sector and academia both in the U.S. and globally, prompted 402 responses. The invitation-only workshop drew 150 people representing 96 selected responses as well as a virtual audience estimated at 2,000.
In all, participants addressed eight ARM and AGC mission topics, with most of their recommendations focused on asteroid observations, redirection technologies and deflection demonstrations, according to the 25-p. report. In addition to greater U.N. engagement, workshop participants suggested greater use of amateur astronomers and the re-purposing of surplus Space Surveillance Network and National Science Foundation observing assets.
Participants also urged greater consideration of deflection strategies and demonstrations using gravity tractors, ion beam deflection, kinetic impact and nuclear approaches. The effectiveness of gravity tractors could be enhanced by transferring mass from the target asteroid to the tractor vehicle, experts suggested. Other recommendations in that arena suggest the ARM target a boulder on a larger asteroid for capture, rather than a small asteroid, in order to increase the target options.
The robotic capture and retrieval phases of the ARM prompted recommendations for the use of robot arm-like booms and space inflatable beams as augmentations or alternatives to NASA’s proposal to enclose the target asteroid with an inflatable bag. Other suggestions included the use of surface-anchored tethers to stabilize a tumbling asteroid and retractable solar arrays to avoid mission-ending damage from an unruly target.
The crew systems arena produced a workshop recommendation for the eventual addition of an augmentation module to the Orion capsule to house astronauts and their equipment on missions ranging beyond the proposed 21-day, two-astronaut ARM rendezvous with an asteroid. NASA’s timeline would identify a target asteroid by 2017-18, followed by the launch of a robotic capture spacecraft equipped with solar-electric propulsion, a technology deemed attractive for a human Mars mission in the 2030s.
The timeline suggests astronauts could rendezvous with the lunar orbiting asteroid on the first piloted test flight of the Orion/SLS combination, as soon as 2021.
Other recommendations on that front urged NASA to look at electrodynamic technologies for protecting spacecraft from corrosive planetary dust particles, as well as to continue spacesuit and spacewalking tool development.
Though NASA emerged favorably from the congressional omnibus appropriations process earlier this year with a $17.65 billion budget for 2014, U.S. lawmakers want detailed cost estimates for the venture and an assessment of impacts on other missions before endorsing the asteroid venture.