Asteroid Redirect Mission

Asteroid Redirect Mission (ARM), also known as the Asteroid Retrieval and Utilization (ARU) mission and the Asteroid Initiative, was a space mission proposed by NASA in 2013; the mission was later cancelled. The Asteroid Retrieval Robotic Mission (ARRM) spacecraft would have rendezvoused with a large near-Earth asteroid and used robotic arms with anchoring grippers to retrieve a 4-meter boulder from the asteroid and bring it to lunar orbit.

The spacecraft would have characterized the asteroid and demonstrated at least one planetary defense technique before transporting the boulder to a stable lunar orbit, where it could have been further analyzed both by robotic probes and by a future crewed mission, Asteroid Redirect Crewed Mission (ARCM).[1] If funded, the mission would have launched in December 2021, with the additional objectives to test a number of new capabilities needed for future human expeditions to deep space, including advanced ion thrusters.[2]

The proposed 2018 NASA budget called for its cancellation, the mission was given its notice of defunding in April 2017,[3] and NASA announced the "close out" on June 13, 2017.[3] Key technologies being developed for ARM have continued, especially the ion thruster propulsion system that would have been flown on the robotic mission.

Objectives

The main objective of the Asteroid Redirect Mission was to develop deep space exploration capabilities needed in preparation for a human mission to Mars and other Solar System destinations[4][5] per NASA's Journey to Mars flexible pathways.[6][7][8][9][10]

Spacecraft overview

The vehicle would land on a large asteroid and grippers on the end of the robotic arms would grasp and secure a boulder from the surface of a large asteroid. The grippers would dig into the boulder and create a strong grip. An integrated drill would be used to provide final anchoring of the boulder to the capture mechanism. Once the boulder is secured, the legs would push off and provide an initial ascent without the use of thrusters.[23][38]

Proposed timeline

Originally planned for 2017, then 2020,[24] and then for December 2021.[44] The mission was given its notice of defunding in April 2017.[3] The launch vehicle would have been either a Delta IV Heavy, SLS or Falcon Heavy. The boulder would have arrived in lunar orbit by late 2025.

Target asteroid

By October 2017, there were 16,950 known near-Earth asteroids,[45] having been discovered by various search teams and catalogued as potentially hazardous objects. By early 2017 NASA had yet to select a target for ARM, but for planning and simulation purposes, the near-Earth asteroid was used as an example for the spacecraft to pick up a single 4 m boulder from it.[23] Other candidate parent asteroids were Itokawa, Bennu, and Ryugu.[46]

The carbonaceous boulder that would have been captured by the mission (maximum 6 meter diameter, 20 tons)[47] is too small to harm the Earth because it would burn up in the atmosphere. Redirecting the asteroid mass to a distant retrograde orbit around the Moon would ensure it could not hit Earth and also leave it in a stable orbit for future studies.

History

NASA Administrator Robert Frosch testified to Congress on "asteroid retrieval to Earth" in July 1980. However, he stated that it was infeasible at the time.[48][49]

The ARU mission, excluding any human missions to an asteroid which it may enable, was the subject of a feasibility study in 2012 by the Keck Institute for Space Studies.[50] The mission cost was estimated by the Glenn Research Center at about $2.6 billion,[51] of which $105 million was funded in 2014 to mature the concept.[52][53] NASA officials emphasized that ARM was intended as one step in the long-term plans for a

See also

External links

• Asteroid Initiative Program by NASA
• YouTube videos:
• Video: Asteroid Redirect Mission, 'Option A', Capture of an 8m free-flying asteroid.
• Video: Asteroid Redirect Mission, 'Option B', Boulder collection from a large asteroid.
• Video: Asteroid Redirect Mission: Crewed Orion spacecraft rendezvous with ARM in lunar orbit
• Video: Asteroid Redirect Mission: Robotic Segment NASA