[meteorite-list] NASA Announces Latest Progress, Upcoming Milestones in Hunt for Asteroids

[Ron Baalke]

June 19, 2014
     
NASA Announces Latest Progress, Upcoming Milestones in Hunt for Asteroids

NASA is on the hunt for an asteroid to capture with a robotic spacecraft, 
redirect to a stable orbit around the moon, and send astronauts to study in 
the 2020s -- all on the agency's human Path to Mars. Agency officials 
announced on Thursday recent progress to identify candidate asteroids for its 
Asteroid Redirect Mission (ARM), increase public participation in the search 
for asteroids, and advance the mission's design.

NASA plans to launch the ARM robotic spacecraft in 2019 and will make a final 
choice of the asteroid for the mission about a year before the spacecraft 
launches. 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 less than 32 feet (10 meters) in size 
into the moon's orbit. The agency will choose between these two concepts in 
late 2014 and further refine the mission's design.

The agency will award a total of $4.9 million for concept studies addressing 
components of ARM. Proposals for the concept studies were solicited through a 
Broad Agency Announcement (BAA) released in March, and selected in 
collaboration with NASA's Space Technology and Human Exploration and 
Operations Mission Directorates. The studies will be completed over a 
six-month period beginning in July, during which time system concepts and key 
technologies needed for ARM will be refined and matured. The studies also 
will include an assessment of the feasibility of potential commercial 
partners to support the robotic mission.

"With these system concept studies, we are taking the next steps to develop 
capabilities needed to send humans deeper into space than ever before, and 
ultimately to Mars, while testing new techniques to protect Earth from 
asteroids," said William Gerstenmaier, associate administrator for NASA's 
Human Exploration and Operations Mission Directorate.

For more information about the BAA and award recipients, visit:

http://go.nasa.gov/1sr6sRn 

NASA's Spitzer Space Telescope made recent observations of an asteroid, 
designated 2011 MD, which bears the characteristics of a good candidate for 
the full capture concept. While NASA will continue to look for other 
candidate asteroids during the next few years as the mission develops, 
astronomers are making progress to find suitable candidate asteroids for 
humanity's next destination into the solar system.

"Observing these elusive remnants that may date from the formation of our 
solar system as they come close to Earth, is expanding our understanding of 
our world and the space it resides in," said John Grunsfeld, associate 
administrator for NASA's Science Mission Directorate. "Closer study of these 
objects challenge our capabilities for future exploration and will help us 
test ways to protect our planet from impact. The Spitzer observatory is one 
of our tools to identify and characterize potential candidate targets for the 
asteroid mission."

Analysis of Spitzer's infrared data show 2011 MD is roughly 20 feet (6 
meters) in size and has a remarkably low density -- about the same as water, 
which supports the analysis of observations taken in 2011.

The asteroid appears to have a structure perhaps resembling a pile of rocks, 
or a "rubble pile." Since solid rock is about three times as dense as water, 
this suggests about two-thirds of the asteroid must be empty space. The 
research team behind the observation says the asteroid could be a collection 
of small rocks, held loosely together by gravity, or it may be one solid rock 
with a surrounding halo of small particles. In both cases, the asteroid mass 
could be captured by the ARM capture mechanism and redirected into lunar 
orbit.

The findings based on the Spitzer observation were published Thursday in the 
Astrophysical Journal Letters. For more information, visit:

http://go.nasa.gov/1lJ61Z2 

To date, nine asteroids have been identified as potential candidates for the 
mission, having favorable orbits and measuring the right size for the ARM 
full capture option. With these Spitzer findings on 2011 MD, sizes now 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 Near-Earth Objects (NEO) Program is finding 
several potential candidate asteroids per 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, 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.

NASA's search for candidate asteroids for ARM is a component of the 
agency's existing efforts to identify all NEOs that could pose a threat to 
the Earth. Some of these NEOs could become candidates for ARM because they 
are in orbits similar to Earth's. More than 11,140 NEOs have been 
discovered as of June 9. Approximately 1,483 of those have been classified as 
potentially hazardous.

In June 2013, NASA announced an Asteroid Grand Challenge (AGC) to accelerate 
this observation work through non-traditional collaborations and 
partnerships. On the first anniversary of the grand challenge this week, NASA 
officials announced new ways the public can contribute to the AGC, building 
on the successes of the challenge to date. To that end, NASA will host a 
two-day virtual workshop -- dates to be determined -- on emerging 
opportunities through the grand challenge, in which the public can 
participate.

"There are great ways for the public to help with our work to identify 
potentially hazardous asteroids," said Jason Kessler, program executive for 
NASA's Asteroid Grand Challenge. "By tapping into the innovative spirit of 
people around the world, new public-private partnerships can help make Earth 
a safer place, and perhaps even provide valuable information about the 
asteroid that astronauts will visit."

For more information about the workshop and public opportunities through the 
grand challenge, visit:

http://go.nasa.gov/1lJ5Son 

The Asteroid Grand Challenge and Asteroid Redirect Mission comprise NASA's 
Asteroid Initiative. Capabilities advanced and tested through the Asteroid 
Initiative will help astronauts reach Mars in the 2030s. For more information 
about the Asteroid Initiative and NASA's human Path to Mars, visit:

http://www.nasa.gov/asteroidinitiative 

-end-

Trent J. Perrotto
Headquarters, Washington
202-358-0321
trent.j.perrotto at nasa.gov