NASA Looks to Lasso an Asteroid

Illustration of an asteroid retrieval spacecraft in the process of capturing a 7-m, 500-ton asteroid. (Image Credit: Rick Sternbach / KISS)

By Douglas Messier
Parabolic Arc Managing Editor

Media reports are indicating that President Barack Obama’s budget will propose that NASA spend $105 million next year to begin a program to capture an asteroid and bring it back to a Lagrangian point near Earth where astronauts would be able to visit it using the Orion spacecraft beginning in 2021.

The Orlando Sentinel reports:

As proposed, the asteroid mission would begin with research — $78 million in 2014 to begin design work on the robotic spacecraft that would capture the asteroid, and an additional $27 million to begin searching the cosmos for an asteroid to grab. The ideal rock would be 20 to 30 feet in diameter and weigh 500 tons….

“If the American people are excited about it, they [lawmakers] will be, too,” said U.S. Sen. Bill Nelson, D-Fla. — adding that he thinks the public is “fascinated” with asteroids thanks to disaster movies such as “Armageddon” and recent near-misses that real space rocks have had with Earth….

“You have to get over the first shock, and I’m worried editorial writers will be like: ‘Huh? You lost your mind,'” acknowledged Lou Friedman, who co-authored a 2012 report that suggested the idea. “But if you get into it, [the mission] is audacious as sending humans to the moon. I think it will restore confidence in America’s technological capability and NASA’s can-do spirit.”

Friedman was co-leader of an April 2012 report sponsored by the Keck Institute for Space Studies (KISS) that concluded it would be possible to return an asteroid weighing approximately 500 metric tons to high lunar orbit where it would be mined for resources by 2025.

The Asteroid Retrieval Feasibility Study was prepared for KISS, NASA Jet Propulsion Laboratory, and the California Institute of Technology (Caltech). John Brophy of NASA JPL/Caltech and Fred Culick of Caltech were co-leaders of the study with Friedman. Participants included representatives of other NASA centers, various universities, institutes and private companies.

Two of the 34 study participants were Planetary Resources President and Chief Engineer Chris Lewicki and former astronaut Tom Jones, who is an adviser to the company. The start-up – which is backed by Google billionaires Larry Page and Eric Schmidt, Microsoft mogul Charles Simonyi, filmmaker James Cameron, and Ross Perot, Jr. – is focused on mining asteroids.

Asteroid return mission concept. Return flight time of 2 to 6 years depending on the asteroid mass. (Source: Asteroid Retrieval Feasibility Study, KISS)

The study examined the possibility of launching an asteroid retrieval spacecraft aboard an Atlas V launch vehicle, which is already operational. The study calculated the “full life-cycle cost of an asteroid capture and return mission at ~$2.6B[illion].” That cost is likely low enough to the mission could be attractive to private companies like Planetary Resources, providing they can locate an asteroid with sufficient resources to make a profit.

Conceptual spacecraft in the cruise configuration with the capture mechanism deployed. (Source: Asteroid Retrieval Feasibility Study, KISS)

Study participants said the mission is feasible and would fit in well with NASA’s long-term objectives for exploring beyond low Earth orbit.

The two major conclusions from the KISS study are: 1) that it appears feasible to identify, capture and return an entire ~7-m diameter, ~500,000-kg near-Earth asteroid to a high lunar orbit using technology that is or could be available in this decade, and 2) that such an endeavor may be essential technically and programmatically for the success of both near-term and long-term human exploration beyond low-Earth orbit….

“The proposed Asteroid Capture and Return mission would impact an impressive range of NASA interests including: the establishment of an accessible, high-value target in cislunar space; near-term operational experience with astronaut crews in the vicinity of an asteroid; a new synergy between robotic and human missions in which robotic spacecraft return resources for human exploitation and use in space; the potential to jump-start an entire industry based on in situ resource utilization; expansion of international cooperation in space; and planetary defense. It has the potential for cost effectively providing sufficient radiation shielding to protect astronauts from galactic cosmic rays and to provide the propellant necessary to transport the resulting shielded habitats. It would endow NASA and its partners with a new capability in deep space that hasn’t been seen since Apollo. Ever since the completion of the cold-war-based Apollo program there has been no over-arching geo-political rationale for the nation’s space ventures. Retrieving an asteroid for human exploration and exploitation would provide a new rationale for global achievement and inspiration. For the first time humanity would begin modification of the heavens for its benefit.

Below are the report’s Executive Summary and Conclusions sections, which provides a good overview of the study. You can also read the full report.

Conceptual ACR spacecraft in the stowed configuration. (Source: Asteroid Retrieval Feasibility Study, KISS)

EXECUTIVE SUMMARY

This report describes the results of a study sponsored by the Keck Institute for Space Studies (KISS) to investigate the feasibility of identifying, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the vicinity of the Earth by the middle of the next decade. The KISS study was performed by people from Ames Research Center, Glenn Research Center, Goddard Space Flight Center, Jet Propulsion Laboratory, Johnson Space Center, Langley Research Center, the California Institute of Technology, Carnegie Mellon, Harvard University, the Naval Postgraduate School, University of California at Los Angeles, University of California at Santa Cruz, University of Southern California, Arkyd Astronautics, Inc., The Planetary Society, the B612 Foundation, and the Florida Institute for Human and Machine Cognition. The feasibility of an asteroid retrieval mission hinges on finding an overlap between the smallest NEAs that could be reasonably discovered and characterized and the largest NEAs that could be captured and transported in a reasonable flight time. This overlap appears to be centered on NEAs roughly 7 m in diameter corresponding to masses in the range of 250,000 kg to 1,000,000 kg. To put this in perspective, the Apollo program returned 382 kg of Moon rocks in six missions and the OSIRIS-REx mission proposes to return at least 60 grams of surface material from a NEA by 2023. The present study indicates that it would be possible to return a ~500,000-kg NEA to high lunar orbit by around 2025.

Bottom view of the conceptual ACR spacecraft showing the five 10-kW Hall thrusters and the RCS thruster clusters. (Source: Asteroid Retrieval Feasibility Study, KISS)

The idea of exploiting the natural resources of asteroids dates back over a hundred years, but only now has the technology become available to make this idea a reality. The feasibility is enabled by three key developments: the ability to discover and characterize an adequate number of sufficiently small near-Earth asteroids for capture and return; the ability to implement sufficiently powerful solar electric propulsion systems to enable transportation of the captured NEA; and the proposed human presence in cislunar space in the 2020s enabling exploration and exploitation of the returned NEA.

Top view of the conceptual ACR spacecraft showing the instrument suite and capture mechanism prior to being deployed. (Source: Asteroid Retrieval Feasibility Study, KISS)

Placing a 500-t asteroid in high lunar orbit would provide a unique, meaningful, and affordable destination for astronaut crews in the next decade. This disruptive capability would have a positive impact on a wide range of the nation’s human space exploration interests. It would provide a high-value target in cislunar space that would require a human presence to take full advantage of this new resource. It would offer an affordable path to providing operational experience with astronauts working around and with a NEA that could feed forward to much longer duration human missions to larger NEAs in deep space. It would provide an affordable path to meeting the nation’s goal of sending astronauts to a near-Earth object by 2025. It represents a new synergy between robotic and human missions in which robotic spacecraft retrieve significant quantities of valuable resources for exploitation by astronaut crews to enable human exploration farther out into the solar system. A key example of this is that water or other material extracted from a returned, volatile-rich NEA could be used to provide affordable shielding against galactic cosmic rays. The extracted water could also be used for propellant to transport the shielded habitat. These activities could jump-start an entire in situ resource utilization (ISRU) industry. The availability of a multi-hundred-ton asteroid in lunar orbit could also stimulate the expansion of international cooperation in space as agencies work together to determine how to sample and process this raw material. The capture, transportation, examination, and dissection of an entire NEA would provide valuable information for planetary defense activities that may someday have to deflect a much larger near-Earth object. Finally, placing a NEA in lunar orbit would provide a new capability for human exploration not seen since Apollo. Such an achievement has the potential to inspire a nation. It would be mankind’s first attempt at modifying the heavens to enable the permanent settlement of humans in space.

Conceptual spacecraft with solar arrays folded back to facilitate matching the asteroid’s spin state during the capture process. (Source: Asteroid Retrieval Feasibility Study, KISS)

The report that follows outlines the observation campaign necessary to discover and characterize NEAs with the right combination of physical and orbital characteristics that make them attractive targets for return. It suggests that with the right ground-based observation campaign approximately five attractive targets per year could be discovered and adequately characterized. The report also provides a conceptual design of a flight system with the capability to rendezvous with a NEA in deep space, perform in situ characterization of the object and subsequently capture it, de-spin it, and transport it to lunar orbit in a total flight time of 6 to 10 years. The transportation capability would be enabled by a ~40-kW solar electric propulsion system with a specific impulse of 3,000 s. Significantly, the entire flight system could be launched to low-Earth orbit on a single Atlas V-class launch vehicle. With an initial mass to low-Earth orbit (IMLEO) of 18,000 kg, the subsequent delivery of a 500-t asteroid to lunar orbit represents a mass amplification factor of about 28-to-1. That is, 28 times the mass launched to LEO would be delivered to high lunar orbit, where it would be energetically in a favorable location to support human exploration beyond cislunar space. Longer flight times, higher power SEP systems, or a target asteroid in a particularly favorable orbit could increase the mass amplification factor from 28-to-1 to 70-to-1 or greater. The NASA GRC COMPASS team estimated the full life-cycle cost of an asteroid capture and return mission at ~$2.6B.

Conceptual flight system configuration before deployment of the capture mechanism showing the locations of the cameras on the solar array yokes used to verify proper deployment and subsequently to aid in the asteroid capture. (Source: Asteroid Retrieval Feasibility Study, KISS)

CONCLUSIONS

The two major conclusions from the KISS study are: 1) that it appears feasible to identify, capture and return an entire ~7-m diameter, ~500,000-kg near-Earth asteroid to a high lunar orbit using technology that is or could be available in this decade, and 2) that such an endeavor may be essential technically and programmatically for the success of both near-term and long-term human exploration beyond low-Earth orbit. One of the key challenges – the discovery and characterization of a sufficiently large number of small asteroids of the right type, size, spin state and orbital characteristics – could be addressed by a low-cost, ground-based observation campaign identified in the study. To be an attractive target for return the asteroid must be a C-type approximately 7 m in diameter, have a synodic period of approximately 10 years, and require a ∆V for return of less than ~200 m/s. Implementation of the observation campaign could enable the discovery of a few thousand small asteroids per year and the characterization of a fraction of these resulting in a likelihood of finding about five good targets per year that meet the criteria for return.

Notional NEA Human Mission Concept of Operations with Pre-deploy. (Sources: Asteroid Retrieval Feasibility Study, KISS)

Proof-of-concept trajectory analysis based on asteroid 2008 HU4 (which is approximately the right size, but of an unknown spectral type) suggest that a robotic spacecraft with a 40-kW solar electric propulsion system could return this asteroid to a high-lunar orbit in a total flight time of 6 to 10 years assuming the asteroid has a mass in the range of 250,000 to 1,000,000 kg (with the shorter flight times corresponding to the lower asteroid mass). Significantly, these proof-of-concept trajectories baseline a single Atlas V-class launch to low-Earth orbit.

The study also considered an alternative concept in which the spacecraft picks up a ~7-m diameter rock from the surface of a much larger asteroid (> 100-m diameter). The advantage of this approach is that asteroids 100-m in diameter or greater are much easier to discover and characterize. This advantage is somewhat offset by the added complexity of trying to pick up a large 7-m diameter rock from the surface, and the fact that there are far fewer 100-m class NEAs than smaller ones making it more difficult to find ones with the desired orbital characteristics. This mission approach would seek to return approximately the same mass of asteroid material – of order 500,000 kg – as the approach that returns an entire small NEA.

Conceptual Human NEA Mission Excursion Vehicle Using SEP System (Image Credit/Source: NASA / AMA, Inc.)

The proposed Asteroid Capture and Return mission would impact an impressive range of NASA interests including: the establishment of an accessible, high-value target in cislunar space; near-term operational experience with astronaut crews in the vicinity of an asteroid; a new synergy between robotic and human missions in which robotic spacecraft return resources for human exploitation and use in space; the potential to jump-start an entire industry based on in situ resource utilization; expansion of international cooperation in space; and planetary defense. It has the potential for cost effectively providing sufficient radiation shielding to protect astronauts from galactic cosmic rays and to provide the propellant necessary to transport the resulting shielded habitats. It would endow NASA and its partners with a new capability in deep space that hasn’t been seen since Apollo. Ever since the completion of the cold-war-based Apollo program there has been no over-arching geo-political rationale for the nation’s space ventures. Retrieving an asteroid for human exploration and exploitation would provide a new rationale for global achievement and inspiration. For the first time humanity would begin modification of the heavens for its benefit.

  • A very interesting proposal, I await further development, unfortunately the USA is becoming very good at talking itself out of doing things. I wonder if they will farm this project to “New space”.

  • Interesting questions. Looking at what is commercially available and what needs to be developed, there’s a good synergy here:

    1. Planetary Resources, Deep Space Industries and B612 Foundation are all working on spacecraft to find asteroids and categorize their compositions. The two companies are particularly focused on identifying asteroids with precious metals and ice. The Foundation is focused on asteroids that could threaten Earth.

    So, the work of identifying promising asteroids to bring back to cis-lunar space could be done privately with NASA financial backing. Space Act Agreements would provide maximum flexibility and allow for partnerships between NASA field centers and companies.

    2. Developing and demonstrating technology capable of pulling an asteroid into cis-lunar space will cost a couple of billion dollars. However, once you accomplish it once, you’ve built the foundation of a transportation infrastructure capable of moving asteroids multiple times. Developing new technologies and infrastructure is the proper role for a government agency like NASA.

    3. In-situ resource extraction and utilization is something that both government and the private sector can develop in parallel. Astrobotic, for example, just got an SBIR Phase I award for developing systems that will allow lunar prospecting rovers to explore the cold, dark polar craters for ice and other volatiles.

    4. This effort assists in human deep space exploration by giving Orion crews somewhere to go and to explore and provides a good rational for these missions.

    5. The timing works fairly well. It’s going to take until around 2021 for Orion to fly with crew, NASA to develop technologies to retrieve an asteroid, and for the private sector and NASA to develop the technologies to identify promising targets and figure out how to extract resources from them.

    6. If you can capture asteroids in this way, you can advance the technologies needed to divert ones that are heading for Earth. And that’s of value to the entire planet.

    7. The technologies needed for the asteroids would be applicable to lunar resources identification and extraction.

  • From Alan Boyle’s story (http://cosmiclog.nbcnews.com/_news/2013/04/06/17630481-administration-confirms-nasa-plan-grab-an-asteroid-then-focus-on-mars):

    Rick Tumlinson, chairman of an asteroid-mining venture called Deep Space Industries,
    said he was concerned that NASA’s asteroid mission might interfere with private-sector efforts — and he called on NASA to rely on private enterprise wherever possible. The administration official assured NBC News that cooperation with commercial ventures as well as other groups such as the B612 Foundation was part of the plan.

  • filecabinet

    Why 2.2 years from LEO to lunar gravity assist? Seems an inordinately long time given a heavy launch vehicle like the Atlas V. What am I missing here?

  • They are using Hall Thrusters for in-space propulsion. They provide efficient, low thrust for a long time (spiral orbit).

  • jb

    Rick has a good point. Investors are starting to see some ways of making money in “new space”. Lets hope the “good synergy” is positive for all involved and having NASA as a backer doesn’t scare off investors. Just wish commercial crew get fully funded so other manned ventures can be done.. it must be driving Bigelow crazy with the delays 🙂

  • filecabinet

    Thanks for that clarification. I’m not an engineer, but it seems as though there must be a faster propulsion architecture available that’s within the mass budget. 2 years!