Experts within NASA and outside are making strides in their plans for a bold Asteroid Retrieval Mission, a joint robotic and human enterprise that would take U. S. explorers beyond low Earth orbit for the first time since the final Apollo mission to the moon.
Artist's illustration of U. S. astronauts exploring small asteroid maneuvered into lunar orbit. Image Credit/NASA.
The series of space flights, which would unfold by 2025 and possibly earlier, would require capabilities that make possible future human missions to Mars or a return to the moon through partnerships forged internationally as well as with the private sector. Humans have not landed on the moon since the 1972 Apollo 17 mission.
Apollo astronauts splash down upon return from final U.S. moon mission. Photo Credit/NASA
Though the price tag faces months more of refinement, it might add up to about $1 billion in new expenditures, primarily because NASA is looking to the Orion/Multipurpose Crew Vehicle and Space Launch System super rocket that are already in development as foundational components. Planners are also looking to scale up Solar Electric Propulsion to robotically capture a 20-30 foot long asteroid or a boulder lifted from the surface of a larger near Earth planetary body as well as technologies and hardware acquired during the shuttle and International Space Station eras. The Keck Institute for Space Studies estimated the cost of a comparable mission at $2.6 billion as a new start.
NASA Briefs Details of Asteroid Mission to AIAA in San Diego
Space agency officials briefed new details of their planning this week at the Aerospace Institute of Aeronautics and Astronautics 2013 Conference and Exposition in San Diego his week.
NASA marks start of 2014 Orion capsule test flight preparations at the Kennedy Space Center. Photo Credit/NASA
The ARM initiative is more than a mission, William Gerstenmaier, NASA’s Associate Administrator for Human Exploration and Operations, stressed as he spoke to the California gathering. It will deliver capabilities and technologies that enable the exploration of Mars, partnerships with international or commercial interests focused on further exploration of the moon and provide techniques for identifying and diverting the rare larger asteroid on a destructive collision course with the Earth.
“You need to turn off that logical side of your brain. You need to turn on the emotional, touchy feely side — the one you never use,” Gerstenmaier told his audience in a lighter moment during his presentation.
A more refined cost estimate should emerge by February, when President Obama presents his 2015 budget proposal to Congress. A late September meeting at the Lunar and Planetary Institute in Houston will sort through nearly 100 mission suggestions submitted in response to NASA request for information in June. Those suggestions, too, are expected to produce innovations that would enable the bold initiative and lower the cost.
Asteroid Capture Could Take Five Years
In 2010, Obama called on NASA to reach an asteroid with human explorers by 2025, and then proceed to the Martian environs by the mid-2030s.
New details for the ARM mission presented at theSan Diegoconference suggest NASA would launch its robotic SEP capture spacecraft on an existing heavy lift rocket, or the new SLS. The robotic spacecraft, fueled with 22,000 pounds of xenon, would begin what could be a five year round trip to its target. As it neared the target asteroid, instruments on the space craft would characterize the structure and composition of the asteroid, perhaps assisted by an independent camera equipped cubesat. Once the asteroid is “bagged” with a flexible enclosure, the probe would start back to Earth, maneuvering eventually into a stable distant retrograde orbit around the Earth’s moon.
The arrival could unfold in time for U. S. astronauts launched aboard an early Orion mission atop the new SLS to rendezvous with the asteroid in 2021.
Astronauts Would Launch on 26 Day Mission to Rendezvous with Asteroid
Once the asteroid was captured into the desired lunar orbit, two astronauts would launch on an Orion/SLS combination for a 26 day mission. After nine days, the Orion crew would rendezvous and dock with the ARM spacecraft using navigational and docking hardware developed or tested during the late shuttle era and for the International Space Station, explained Steve Stich, deputy director for engineering at NASA’s Johnson Space Center, told the San Diego conference.
Artists illustration of NASA Space Launch System launch. Image Credit/NASA
The astronauts would remain docked for five days, conducting two spacewalks to examine and gather samples of the asteroid. As it launched, the robotic ARM spacecraft would carry the tools and other equipment required by the astronauts, said Stich. The journey back to Earth would take 11 days.
Solar Electric Propulsion An Enabling Technology
Smaller scale solar electric propulsion s operating currently in space on NASA’s Dawn probe. Launched in 2007, Dawn has already explored Vesta in the main asteroid belt and is on its way to Ceres. SEP technology is also controlling communications spacecraft in high Earth orbit.
However, upgrades and multiple engines requiring 50 to 100 kilowatts of solar power would be necessary for the ARM mission. Later, those same technologies would likely launch supplies and fuel to Mars for the first U. S. explorers sent to the red planet, James Reuther, deputy associate administrator in NASA’s Space Technology Mission Directorate, told the AIAA audience.
“This is something we have not come close to doing, but it is of course the kind of capability that we will need if we want to get serious about using high powered SEP for deep space human exploration,” said Reuther.
Strides in SEP could also carry robotic spacecraft on science mission to uncharted territory outside the solar system.
Orion was not designed with an airlock for spacewalks. But NASA is already testing an enhanced version of the launch and entry suits worn by shuttle astronauts for the ARM spacewalk role, said Stich.
The destination lunar orbit is stable enough to keep its visitor circling the moon for at least a century, accessible to future Orion crews, commercial or international mission spacecraft.