Use asteroids as stepping stones to Mars: Richard Binzel on NASA's asteroid redirect mission

Richard Binzel on NASA’s asteroid redirect mission
This concept image shows an astronaut retrieving a sample from the captured asteroid. Credit: NASA

By the end of this decade, NASA hopes to lasso a space rock: The space agency is actively pursuing proposals for its Asteroid Redirect Mission (ARM)—a mission that aims to identify, capture, and redirect an asteroid into lunar orbit. Astronauts might then visit the rock to collect and bring back samples—pieces that would presumably hold remnants of the early solar system. ARM has been touted as a steppingstone toward the ultimate goal of sending humans to Mars: The mission would advance technologies and spaceflight experience needed for humans to colonize the Red Planet.

However, ARM may be a misstep for NASA, according to Richard Binzel, an MIT professor of planetary sciences. In a commentary published today in the journal Nature, Binzel argues that capturing a faraway asteroid is unnecessary and wasteful. Instead, he says, a trove of near-Earth asteroids, in native orbits as close as the moon, may be close enough for astronauts to visit.

Binzel spoke with MIT News about the need for NASA to pursue a more "pragmatic" path to Mars.

Q. How will finding asteroids that are within the reach of human spaceflight help us in ultimately sending humans to Mars?

A. Right now, Mars is too far for us to reach. Yet we need a challenge of somewhere to go when we are ready to take our first steps out of the Earth-moon cradle and become interplanetary travelers. This newly recognized, enormous population of near-Earth asteroids—roughly 10 million of them larger than 10 meters [in diameter] that orbit between Earth and Mars—serve as natural milestones to measure our progressing capability to travel farther and for longer durations.

Most practically, one can conceive that humans will touch the Martian moon Phobos before a later mission to the surface of Mars. The reason for considering Phobos is that landing on Mars requires bringing a return rocket with you. However, Phobos' low gravity doesn't require any significant extra propulsion system to come home.

A survey will find a huge number of accessible nearby asteroids. Perhaps a few of these close-by objects will be as large as 100 meters across—a size that provides some meaningful practice for human operations at Phobos.

Q. In your commentary in Nature, you take NASA to task for ARM. In particular, you call the hardware and operations associated with such a mission "dead-end elements with no value for long-duration manned space travel." Why is this mission such a misstep for NASA?

A. ARM has been widely criticized, and it is the National Research Council that calls these "dead-end elements." Getting to Mars is all about expanding the distance and duration capability of human spaceflight. Nothing about capturing an asteroid in a baggie, or grabbing an asteroid boulder with an arcade-game claw, has anything to do with the challenge of getting astronauts to Mars.

Some argue that the asteroid-towing system, employing solar-electric propulsion, is important for eventually sending supplies to Mars. I say, if you want to test out a supply system, use solar-electric propulsion to tow supplies in the first place. Astronaut rendezvous with a rock in a baggie that was towed into is of no benefit to the crew's safety and well-being.

If, instead, astronauts arrive in a distant lunar orbit and rendezvous with a supply module that has been towed there in advance, they can extend their total mission time. Extended mission time in deep space is exactly the type of expanding capability we need for humans one day reaching Mars.

Bottom line is that asteroid retrieval offers no reasonable direct benefit for a human spaceflight program whose horizon goal is Mars.

Q. You write that NASA "needs to get back on a coherent track toward achieving humankind's next giant leap in space." What are some ways NASA can get back on track, in a fiscally attractive manner, that can also lead to a broader future in space exploration?

A. Finding these easy-to-reach interplanetary asteroids passing near the Earth is far more fiscally responsible than an asteroid-retrieval stunt. A survey, even if using space-based satellites, would be a fraction the cost of a multibillion-dollar retrieval mission. Retrieval would get you one asteroid, while a survey would reveal thousands at a fraction of the cost.

I also advocate that NASA open a "grand challenge competition" to select the best possible, most cost-effective survey mission. This competitive process has been done multiple times with great success with NASA's unmanned planetary probes.

Here's why a survey gets and public imagination back on track: Imagine actually knowing the exact orbits and basic nature of the 1,000 most accessible asteroids that are 10 meters or larger. I believe that actually seeing those objects "just right there" in Earth's vicinity, where getting to any one of them takes less propulsion than getting to the lunar surface, is the equivalent of the St. Louis Gateway Arch.

Once we factually know they are there, human capability will be driven to expand to meet them. From a fiscal point of view, we will know exactly what we are aiming for, and thus be able to plan our steppingstones to Mars most directly and cost-effectively. Speaking economically, if commercial viability would actually become true—I am dubious that will occur within 50 years, but I hope I am wrong—knowing exactly where/what/how many opportunities exist is absolutely essential to opening the widest possible gateway for humans to expand into the solar system.


Explore further

NASA seeks proposals to develop capabilities for deep space exploration, journey to Mars

More information: "Human spaceflight: Find asteroids to get to Mars." Richard P. Binzel. www.nature.com/news/human-spac … -get-to-mars-1.16216
Journal information: Nature

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

Citation: Use asteroids as stepping stones to Mars: Richard Binzel on NASA's asteroid redirect mission (2014, October 30) retrieved 23 October 2019 from https://phys.org/news/2014-10-asteroids-stones-mars-richard-binzel.html
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Oct 30, 2014
What is this obsession with gravity wells? Once we leave this one we stay out of all wells. They are only fit for banishing miscreants to.
Forget Mars- it is a nasty place. Create civilization using materials sourced from low gravity objects.
And forget your obsessions with gravity holes.

Oct 30, 2014
a major rocket mission just exploded. it is using 50 year old designs for rockets. you really think we're going to mars? mr zubrin thought so, and his dreams were crushed on 30 years of promises promises.

the timing is wrong wrong wrong. we wont be sending a manned mission to mars anytime before 2050. everyone knows it. please redirect your efforts somewhere productive, for example into other areas of current space research.

cjn
Oct 30, 2014
Human space flight isn't necessary for asteroid retrieval. Pursuing it, even as an intermediate for human exploration of Mars is requiring an unnecessary investment for human considerations, when funding should be concentrated on propulsion, energy generation and storage, sustainment, and recovery. Once we have those techs down, we can start to prep our destinations with unmanned missions while we figure out how to get people there and back safely (and sanely). All these unmanned mission could be scouting for water, constructing habitats (3D printing?), refining materials, establishing comm networks, growing food supplies, and collecting fuel/energy to limit the logistics load necessary for human trips.

Oct 30, 2014
The bureaucrats over at NASA actually have zero interest in actually going to Mars, their entire focus is making sure they have an empire and a life long job making money rather than gasp, actually work for a living. This asteroid gather is pure nonsense, it will cost billions divert resources from actually doing something about going to mars while making all the NASA big wigs better off. NASA original plans back in 1962 where moon colonies by the seventies and a colony on the mars in the eighties. They never mentioned a single word about asteroids but did have in the mid 60's a working Nerva nuclear rocket engine to get you there.

Oct 30, 2014
Extensive manned space explorations is pretty pointless and expensive with current chemical rocketry technology. Unless we use nuclear power or discover something much better, I won't think we will get anywhere soon for the next decade or two.

Oct 30, 2014
Extensive manned space explorations is pretty pointless and expensive with current chemical rocketry technology. Unless we use nuclear power or discover something much better, I won't think we will get anywhere soon for the next decade or two.


i agree, the rapid pace of development of miniaturization of computers, and the increase in their ability to be able to intelligently controll robotic bodies means that the future of space exploration is undoubtedly using smaller more sophisticated and intelligent robots that can be launched ever more efficiently. the positive feedback loop of better technology leading to cheaper package weights and launch costs means that there is no poitn paying attention to the dreams who insist humans will travel beyond near earth orbit anytime soon. after all, it's been 40 years since any human landed on the moon. we chose not to repeat bad investments in over-expensive missions relative to the alternative unmanned missions. that won't change.

Oct 30, 2014
ARM may actually be one of those, two birds with one stone kind of missions. One problem with a manned long endurance mission to Mars is radiation shielding , for example: how to protect the crew from an unpredictable CME? Weight limitations and costs weigh heavily on NASA. Sending sand bags and filling them in space could provide some protection from solar radiation and micro-meteors. Pioneers must learn to live off the land, even if there isn't any.

Oct 31, 2014
This politics driven obsession with bottoms of gravity wells is waste. I blame Hollywood sci-fi.

Live off the land, use close by asteroids for various materials which are extremely expensive just because they have to be ferried 10km/s far, use those at under 1km/s or close.

Once we have access to cheap materials in space, with propulsion made for space, we can go anywhere, claim this solar system, perhaps in less than 100 years.

Oct 31, 2014
A round trip to mars is a small victory compared to having an economically profitable asteroid in orbit around the earth which you can get more easily.

if you practice asteroid capture, you have a decent chance at capturing the Apophis asteroid in 2029.

The asteroid Apophis (likely one of those LL chondrites) contains enough materials to construct about 150 five-gigawatt solar power satellites at 25,000 tons of steel and silicon each, plus Kalpana One style habitats for 100,000 people, all shielded by the slag remaining after iron is smelted out of asteroid ore.

here's a project outline. . .
http://www.nss.or...ure.html

Oct 31, 2014
A round trip to mars is a small victory compared to having an economically profitable asteroid in orbit around the earth which you can get more easily.

Try doing the calcs on that one (cost for such a mission vs sales value of any kind of materials). Not gonna happen any time soon.

To smelt andmanufacture stuff you have to get serious production factories and power plants into orbit. Currently we're shipping largish washing machine sized objects and battery packs.

Oct 31, 2014
Binzel doesn't care much for the requirements on time and mone that has put NASA in a bind, and he is wrong on the achievements. His goal is to maximize his planetary science, which is starved by the Monster Pork Rocket To Nowhere.

It is because NASA has no NEA in reach at the time and within the budget they want to make the first trans-lunar mission, that they are considering a cheaper capture and tow. It would still test the upgraded Orion/SM that would be needed beyond LEO.

@Skepticus: Why wait? We can afford this, it is cheap comparable to other development stuff we do. And full speed ahead on whatever budget we can afford nets us more faster than not investing in any attempts at all.

@Eagleton: I agree with the overall goal. But this is about near term exploration.

Dug
Oct 31, 2014
Extended space exploration and colonization - while necessary for the ultimate survival of our species are currently impossible with available technology and critical finite resource economics. While technology can be expanded, critical resources are finite. The energy (primarily fossil fuel) and related chemicals necessary to process and reprocess critical resources like petroleum and phosphates - necessary for basic survival needs (i.e. food production) are currently declining at a rate that will bring us to a civilization collapse (over population/resources) in less than thirty years. Unless a new energy paradigm is created to achieve energy at near "zero - free" costs, our civilization and perhaps our species will be lost. Lockheed Martin announced the practical application of a fusion reactor this past week to happen in less than a decade. Maybe that's soon enough - maybe not - and they didn't say at what costs.

Oct 31, 2014
Extended space exploration and colonization - while necessary for the ultimate survival of our species are currently impossible with available technology and critical finite resource economics.

Exploration - yes. Colonization? Well that may not be necessary for the long term survival of the species.
Not if we think body alteration or going fully tech. In that case you have no need for a colony. Think about WHY humans settle - if those needs are gone then a colnoy makes little sense. (And an economy isn't needed under these circumstances, either)

Dug
Oct 31, 2014
My point was that without first being aware of available critical resource/economic (physical and fiscal) limitations, planning for things like inter-planetary space flight is either disingenuous, intellectually incompetent - or both.
Regarding needing an economy or not - you are thinking only fiscal economics. Physical economics will always be needed - i.e. energy.

With regard to a Singularity - while we not be as resource constrained compared to inter-planetary space travel - the technological and necessary associated integration of neuroscience and quantification of other metabolic effects and the interrelationship knowledge - appear much further away than three decades, not mention the expense of the necessary research which is much more linear that computer processing development - regardless of Moore's (so called law) and no matter what engineer (field) - limited futurists like Kurzweil - simplistically imagine. You can't process (or budget) what you don't begin to know.

cjn
Nov 03, 2014
if you practice asteroid capture, you have a decent chance at capturing the Apophis asteroid in 2029.

The asteroid Apophis (likely one of those LL chondrites) contains enough materials to construct about 150 five-gigawatt solar power satellites at 25,000 tons of steel and silicon each, plus Kalpana One style habitats for 100,000 people, all shielded by the slag remaining after iron is smelted out of asteroid ore.

here's a project outline. . .
http://www.nss.or...ure.html


Hadn't heard about this before. Its a really awesome idea and a massively rewarding technical challenge. Knowing that we'll never get our collective heads removed from their cavities in time to actualize on this, I'm already lamenting the loss of such a visionary effort.

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