What is the goal for the Asteroid Redirect Mission?
Through the Asteroid Redirect Mission, NASA will identify, capture and redirect an asteroid to a stable orbit around the moon, which astronauts will explore in the 2020s, returning with samples. The mission is an important early step as we learn to be more independent of Earth for humans to explore Mars. It will be an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities, while helping us learn to protect our home planet. The overall objectives of the Asteroid Redirect Mission are:
• Conduct a human exploration mission to an asteroid in the mid-2020s, providing systems and operational experience required for human exploration of Mars.
• Demonstrate an advanced solar electric propulsion system, enabling future deep-space human and robotic exploration with applicability to the nation’s public and private sector space needs.
• Enhance detection, tracking and characterization of Near Earth Asteroids, enabling an overall strategy to defend our home planet.
• Demonstrate basic planetary defense techniques that will inform impact threat mitigation strategies to defend our home planet.
• Pursue a target of opportunity that benefits scientific and partnership interests, expanding our knowledge of small celestial bodies and enabling the mining of asteroid resources for commercial and exploration needs.
What are the requirements for the asteroid NASA hopes to capture?
NASA is working on two concepts for the mission: the first is to fully capture a very small asteroid in open space, and the second is to collect a boulder-sized sample off of a much larger asteroid. Both concepts would require redirecting an asteroid mass less than 32 feet (10 meters) in size into the moon’s orbit.
NASA’s search for candidate asteroids for ARM is a component of the agency’s existing efforts to identify all Near-Earth Objects (NEOs) that could pose a threat to the Earth. More than 11,140 NEOs have been discovered as of June 9. Approximately 1,483 of those have been classified as potentially hazardous. Some of these NEOs become potential candidates for ARM because they are in orbits very similar to Earth’s and come very close to the Earth-Moon system in the early 2020s, which is required to be able to redirect the asteroid mass to be captured into lunar orbit.
To date, nine asteroids have been identified as potential candidates for the ARM full capture option, having favorable orbits and estimated to be within the right size range. Sizes have been established for three of the nine candidates. Another asteroid — 2008 HU4 — will pass close enough to Earth in 2016 for interplanetary radar to determine some of its characteristics, such as size, shape and rotation. The other five will not get close enough to be observed again before the final mission selection, but NASA’s NEO Program is finding a few additional potential candidate asteroids every year. One or two of these get close enough to Earth each year to be well characterized.
Boulders have been directly imaged on all larger asteroids visited by spacecraft so far, such as Itokawa by the Japanese Hayabusa mission, making retrieval of a large boulder a viable concept for ARM. During the next few years, NASA expects to add several candidates for this option, including asteroid Bennu, which will be imaged up close by the agency’s Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) mission in 2018. High resolution interplanetary radar is also able to image the surfaces of asteroids that pass close to the Earth and infer the presence of large boulders.
Where will the asteroid be redirected to – reports suggest above the Moon?
After an asteroid mass is captured, the spacecraft will redirect it to a stable orbit around the moon called a “Lunar Distant Retrograde Orbit.” Astronauts aboard an Orion spacecraft, launched from a Space Launch System (SLS) rocket, will explore the asteroid there in the mid-2020s. Learning to maneuver large objects utilizing the gravity fields of the Earth and moon will be valuable capabilities for future activities. Potentially, either mission concept might test technology and techniques that can be applied to planetary defense if needed in the future.
How will ARM fit NASA’s goal to visit Mars?
The mission provides experience in human spaceflight beyond low-Earth orbit, building on our experiences on the International Space Station, and testing new systems and capabilities in the proving ground of cis-lunar space, toward the ultimate goal of a crewed mission to Mars. ARM leverages and integrates existing programs in NASA’s Science, Space Technology, and Human Explorations and Operations to provide an affordable – and compelling — opportunity to exercise our emerging deep space exploration capabilities on the path to Mars. ARM will test the transport of large objects using advanced high power, long life solar electric propulsion; automated rendezvous and docking; deep space navigation; integrated robotic and crewed vehicle stack operations in deep space environment; and spacewalks out of Orion that will be needed for future cis-lunar space and Mars missions.
NASA’s strategy is that the ARM SEP module and spacecraft bus would be upgradable for the first cargo missions to Mars and its moons. We might do so by procuring these systems commercially to lower cost and for reproducibility. Another option is to repurpose the ARM vehicle after its first mission, as a lowest cost option for transportation. These are among the options being studied this year.