Space

NASA outlines Asteroid Redirect Mission

Asteroid Redirect Vehicle landing (Image: NASA)
Asteroid Redirect Vehicle landing (Image: NASA)
View 12 Images
Artist's concept of a Solar Electric Propulsion system (Image: NASA)
1/12
Artist's concept of a Solar Electric Propulsion system (Image: NASA)
An ion thruster in action
2/12
An ion thruster in action
Asteroid Redirect Vehicle landing (Image: NASA)
3/12
Asteroid Redirect Vehicle landing (Image: NASA)
Asteroid Redirect Vehicle travels to lunar orbit (Image: NASA)
4/12
Asteroid Redirect Vehicle travels to lunar orbit (Image: NASA)
Asteroid Redirect Vehicle making a flyby assessment (Image: NASA)
5/12
Asteroid Redirect Vehicle making a flyby assessment (Image: NASA)
Once the boulder is secured, the ARV will mechanically hop from the surface and then use thrusters to ascend from the asteroid’s surface (Image: NASA)
6/12
Once the boulder is secured, the ARV will mechanically hop from the surface and then use thrusters to ascend from the asteroid’s surface (Image: NASA)
Asteroid Redirect Vehicle descends to asteroid surface (Image: NASA)
7/12
Asteroid Redirect Vehicle descends to asteroid surface (Image: NASA)
An astronaut uses a covered chisel tool to extract a sample of the asteroid for return to Earth (Image: NASA)
8/12
An astronaut uses a covered chisel tool to extract a sample of the asteroid for return to Earth (Image: NASA)
Microspine grippers on the end of the robotics arms are used to grasp and secure the boulder (Image: NASA)
9/12
Microspine grippers on the end of the robotics arms are used to grasp and secure the boulder (Image: NASA)
Orion docks with the Asteroid Redirect Vehicle (Image: NASA)
10/12
Orion docks with the Asteroid Redirect Vehicle (Image: NASA)
Close-up of the Asteroid Redirect Vehicle departing the asteroid after capturing a boulder from its surface (Image: NASA)
11/12
Close-up of the Asteroid Redirect Vehicle departing the asteroid after capturing a boulder from its surface (Image: NASA)
An astronaut, anchored to a foot restraint, prepares to investigate the asteroid boulder (Image: NASA)
12/12
An astronaut, anchored to a foot restraint, prepares to investigate the asteroid boulder (Image: NASA)

NASA has released new details on how it plans to boldly go to an asteroid and come back with a bit of it. The Asteroid Redirect Mission (ARM) is part of the space agency's Asteroid Initiative announced in 2013, which envisions the capture and return of an asteroid to lunar orbit for study by astronauts as a rehearsal for a later mission to Mars.

Scheduled to begin in 2020, the purpose of the ARM is to test new technologies and techniques that would be needed for later manned deep space missions while learning more about asteroids and how to defend the Earth against them. This involves sending a robotic spacecraft to collect a boulder from a near-Earth asteroid, then return it to lunar orbit, where a later manned mission will rendezvous to retrieve samples.

The ARM will begin with an unmanned Asteroid Redirect Vehicle being sent to a target asteroid, which has yet to be selected. The collector spacecraft will travel to the asteroid on a multi-year trajectory using Solar Electric Propulsion (SEP). This uses solar panels to power ion thrusters that provide a very low, constant thrust for years on end by charging xenon atoms and accelerating them. The system is currently being used on the Dawn mission and NASA hopes that it could one day be used to preposition supply craft for a Mars mission.

An astronaut, anchored to a foot restraint, prepares to investigate the asteroid boulder (Image: NASA)
An astronaut, anchored to a foot restraint, prepares to investigate the asteroid boulder (Image: NASA)

Once at the asteroid, the spacecraft will select a likely boulder and collect it using its robotic arms equipped with microspine grippers, then lift it off by hopping and using thrusters. NASA says it will take about six years to bring the boulder back to Earth. On return, the Asteroid Redirect Vehicle will go into a distant retrograde orbit around the Moon at a distance of 61,500 km (38,200 mi), which is very stable and requires relatively little energy to reach. This will not only place the returned boulder within the reach of astronauts, it will also test the orbit's suitability for parking future interplanetary spacecraft, such as a Mars mission habitat.

Another objective of the asteroid return mission will be to test methods for defending the Earth against asteroid strikes. One of these will be to use the mass of the Asteroid Redirect Vehicle and its boulder cargo as an interplanetary tug called a gravity tractor. By going into a halo orbit around the target asteroid and orienting in a particular direction, this will pull the asteroid minutely and while this fractional change might not seem like much, over hundreds and millions of miles that deflection can add up, making the difference between a hit and a miss.

After the boulder has been placed into lunar orbit in the mid-2020s, NASA will launch an Orion spacecraft with two astronauts aboard on a 25-day mission to rendezvous with the asteroid fragment for study and collecting samples. While there, the astronauts will test new sensors and a new docking system to link the Orion and the Asteroid Redirect Vehicle, after which the astronauts will spacewalk to the boulder using a new generation of spacesuits.

Artist's concept of a Solar Electric Propulsion system (Image: NASA)
Artist's concept of a Solar Electric Propulsion system (Image: NASA)

NASA says it will select a target asteroid by 2019, which will be about a year before the unmanned collector spacecraft is launched. These will be assessed based on size, shape, rotation, and orbit. The current candidates include the asteroids Itokawa, Bennu, and 2008 EV5, but up to two more candidates will be added each year until the mission starts.

The collection of asteroid samples will also help train astronauts and mission managers in how to collect and secure samples for return on future Mars missions.

"The Asteroid Redirect Mission will provide an initial demonstration of several spaceflight capabilities we will need to send astronauts deeper into space, and eventually, to Mars," says NASA Associate Administrator Robert Lightfoot. "The option to retrieve a boulder from an asteroid will have a direct impact on planning for future human missions to deep space and begin a new era of spaceflight."

The agency is asking the US Congress for US$50 million towards the mission in the 2016 budget.

The animation below shows one of the latest scenarios envisioned for the asteroid return mission.

Source: NASA

Asteroid Redirect Mission: Crew Segment

5 comments
zevulon
redirecting asteroids will be like man going to the moon in the 70s. we do not yet have the technology to make it worthwhile and attempts at redirecting asteroids are not only premature wastes of money, but unfortunately likely to poison the well for a future where, with superior technology, we may in fact have very good reasons for making missions to asteroids. one wonders whether, had we not prematurely visited the moon in the 70's, whether, with our currently superior technology, we might not be a more frequent and fruitful visitor to the moon today. all we really got from the 70's moon missions were some bags of rocks and soil samples. most of what we now about the moon has been accomplished by remote sensing from terrestiral observation, low earth orbit, or non-human satellites place in orbit around the moon. perhaps it is now a great time for man to visit the moon, but we already had been to the moon and now, we lack the will power to go back.
slickrickulous
@zevulon This kind of logic never made sense to me. This is like saying if Galileo didn't waste his time with his primitive telescope and the scientific community waited for better technology, terrestrial observations would be further progressed than they are today. Technology doesn't grow on trees. Breakthroughs come about because of these early forays, not in spite of them. If NASA hadn't built the Saturn V then there wouldn't be anything to base the designs of the Orion launcher off of and no reason to even think building a launcher of that size is remotely possible.
Kevin Ritchey
We seem to be forgetting about the asteroids that have and will come to us. Why not snag one of those rather than wait so many years just to bring back a boulder? We have many that pass reasonably close to Earth. Why not use these as test beds for our deflection ideas and collect samples in the same instance. I don't care for the idea of wasting time and money going to retrieve something so insignificant when we have likely candidates passing nearby. Besides, we need to start utilizing our moon more and it's right outside our windows. Seems that it has seen more asteroids close up than any one of us. Just look at the damn thing. There's sure to be plenty of spare samples left there, despite being contaminated by "moon pigeons."
Charles S Roscoe
Strap nukes to the large potentially hazardous Apophis asteroid as it passes by in 2029 or 2036 timed to detonate and blow it into small pieces when it it is furthest away in its outbound orbit. End of problem.
David Finney
Seems like a haphazard attempt. Crawling outside of the ship to scrape off some material? Isn't there a better way to go about this? Perhaps an intra-vehicle activity? Risking a human to scrape off material seems, excessive. How about a capture vehicle that has a rudimentary lab on there to do some preliminary studies on material? One that will prep the material for the astronauts to return with. No EVA needed.