NASA mulls plan to drag asteroid into Moon's orbit
newscientist.com
newscientist.com
The concept caught some tailwind -- from the manned side of NASA -- and HQ started talking about it as a possible mission concept that would be a step on the manned roadmap. Such fast uptake of a mission concept is incredibly rare.
Then the larger asteroid science community took interest, and was somewhat disgruntled because the concept had not been vetted by the community at large. Controversy ensued throughout 2013 -- partly centered on selection of an asteroid -- here is a good summary: http://news.sciencemag.org/space/2013/07/nasa-warned-go-slow...
The concept is now called the "asteroid initiative" and I think it is also associated with enhancing NEO detection. The web site is here: http://www.nasa.gov/asteroidforum/#.U151pF7fPRo
This has nothing to do with Mars. NASA's current political climate is to say that Mars is their goal and everything is a stepping stone towards it, but this isn't providing any of the key technologies we need for a manned Mars mission (heavy lift, artificial G, Mars landing craft).
EDIT: Not that this is without value. But sell it on its own merits. Saying "we need to mine asteroids to go to Mars" is making it harder to go to Mars.
Especially research into mining the rocks / getting humans to do that.
We probably need in-situ resource production of fuel from the Martian atmosphere. Which this mission is not providing.
In retrospect it's pretty clear what this is:
1. NASA wants to do an asteroid capture mission (Planetary got so much press, we can too)
2. NASA leadership says their goal is Mars
3. A bunch of post hoc reasons to say that this is moving us towards Mars.
If you were designing a Mars mission, you would never put "let's go capture an asteroid and bring it into lunar orbit" into your schedule anywhere.
But lo, once that technology becomes available and reliable, does it not inherently serve the purpose? If the stated goal of asteroid mining— that being to more cheaply access raw materials and potentially make use of them while still in orbit— is successful, would it not immediately contribute to any and all future missions including Mars and beyond?
You are free to speculate as to the viability of such a proposal, certainly, but if you cannot see the obvious potential in saving having to launch thousands of pounds of raw materials into space then I'm afraid few people would be willing to consider what other thoughts you may have on the matter.
Mining useful things in outer space is at least 10 years away, plus at least another 10 to make it "reliable."
And what would it accomplish? If you brought an asteroid full of volatiles into LEO, and then converted it into LOX and LH2 before the asteroid burnt off and then developed a cryogenic storage system and then used a constant supply of the fuel for station keeping, you could have a fueling station in LEO. So I guess you could launch a smaller rocket from Earth, spend fuel to rendezvous with the fuel station, fuel up, and then go to Mars.
How much will that save you? A Falcon 9 launch is about $50 million. A SpaceX developed heavy-launch will probably cost $100 million or $200 million, but maybe you could get by with a Falcon 9 for about $50 million.
So, you've saved $50 million to $150 million, assuming this all works perfectly, on a mission that will costs several billion, and massively increased the complexity by requiring a stop and refueling in orbit. (And I pretended that bringing the asteroid into LEO and keeping it there and mining it there and preserving the fuel there all had a cost of $0.00.)
This isn't a "stepping stone." This is at best a side show, at worst a permanent delay to a manned Mars mission, because these kind of "well, once that technology becomes available and reliable, it would help, right?" issues are limitless. There is no end of the things that you could do instead because they might eventually some day if everything works right make a Mars mission a tiny margin easier.
This is exactly the problem the SEI had when designing a trip to Mars. Bush said he wanted one, and so NASA put every possible thing they could on the critical path to make sure everyone's pet technology would get funded.
It got a price tag of $450 billion and Congress reacted by zeroing out every single expenditure for it.
Here are REAL stepping stones:
1. Build a heavy-launch vehicle.
2. Put a lab onto Mars capable of manufacturing fuel from the Martian atmosphere.
3. Develop a landing system to put a 10+ ton payload onto the surface of Mars.
4. Launch a few spacecraft with artificial gravity and after several unmanned launches put some people in them for a few days / weeks / months (doing some other mission if you want).
We need experience in maneuvering and setting up a spinning craft and also playing through its failure modes.
[1] They did it exactly once, from my memory, but I forget the details.
There has been some experimentation with this, such as during Gemini 11 when they did it very slowly with an Agena, but there needs to be more work with it.
It would give a really good reason to dust off NERVA, the engine tech Nasa planned to use for a Mars mission in the '70s. Safe, too. NERVA for pushing asteroids around would keep the prototype engines far away from both astronauts and Earth.
Having it in Earth orbit is no great challenge - better to have it further out of the gravity well to be a better staging post, and there's more to be learned from having to go back and forth to it further out.
Look at the Mercury, Gemini, and Apollo missions. Each one was specifically designed to learn something new that was essential for the Moon landing. This seems designed for maximum learning and not just for the individual challenge.
You want to practice remote mining, do it on the moon, or at the bottom of the sea, or in a deep-core mineshaft here on earth. All simpler than going to the asteroid and bringing back gigatons of rock.
> We choose to go to the moon in this decade and
> do the other things, not because they are easy,
> but because they are hard, ...
Many other obstacles present themselves, but these two are huge enough.
We have a 2kW nuclear reactor rolling around Mars at the moment. 400 watts in the interstellar neighborhood. 200W currently en route to Pluto.
Maybe you think nuclear is cheating? Solar might make more sense for this mission anyway, since it is in the Earth-Venus neighborhood. The Rosetta probe would generate almost 10kW at that distance from the sun.
You are ignoring heat output. Curiosity's reactor produces 2kW of heat and 125W of electricity. The heat is more important - it is what keeps the rover from dying at night.
Heat output is really useful for propulsion - more useful than electric if you need large amounts of thrust. Something like NERVA would help get astronauts to Mars before the radiation dose gets too high. Or if you wanted to give an asteroid the biggest push possible.
Those are just RTGs. You can also put a proper fission reactor into space as well. This has been done in the past several times to power active radar surveillance satellites. They've been around since the early 70s, the TOPAZ-II from the early 90s could put out around 10kW. TOPAZ-I[aka TOPAZ] could do 5kW.
As you would expect, they put out even more power as heat. Those 5kW-10kW numbers are just what you get in electrical power, through the thermionic converters, which are not particularly efficient.
TOPAZ reactors are about half the mass of Voyager I.
The upper bound on mass that we've already put into interplanetary space is probably the five S-IVB stages in heliocentric orbit right now, each with a dry mass of about 10,000kg. That's about 10 TOPAZ-II's or 30 TOPAZ's. There was a proposed manned Venus flyby mission using a wet-workshop S-IVB, which would have been much heavier.
It would be great to use them in space though; it would probably be much easier to convince the public to go for that.
The most likely failure is just the device coming apart and being scattered, but in that situation Pu-239 is not particularly more concerning than Pu-238. More or less just an alpha emitter; not good to ingest, but otherwise pretty safe. We've launched plenty of things with Pu-238 in board.
We've had thousands of H-bombs on top of rockets for decades and a number of live fire tests where bombs delivered by missile detonated and so far there have been no accidental detonations.
I love nuclear but it's not always the best answer. (OTOH, it is the best answer for anything that's going to land some place and need to function for more than a few months.)
I don't disagree with you entirely, it is simpler to emulate an environment.
One is traveling at breakneck speed, the other is (relatively) stationary.
One is at negative pressures, the other at ~15,000 psi.
One requires you to burn millions of gallons of fuel to access, the other only requires a brief jaunt out onto the ocean and then hopping off the boat.
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1999+AO10&orb=1 (Requires Java applet to view)
Once it's in orbit around the moon it's not going anywhere.
It's a question of how high it is, too.
NB: I didn't know this until I asked /r/space about it several years ago.
I'm not saying it's not worth doing; I'm just saying when humans see ___ can be done, enough of them get the idea of weaponizing ___ and we should keep that in mind.
Perhaps we should simultaneously consider what defenses could be put in place ... this has the benefit of being useful planetary defense against "natural" earth-impacting rocks, too.
Also, why not?
So until we'll be able in practice to make everything out of electricity, dust and the power of will, we need various resources for our survival and growth.
I'm not convinced that asteroid mining would be more productive than, say, tapping into rift zones, but it's an interesting problem. Might be useful to solve.
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Notes:
1. https://en.wikipedia.org/wiki/Asteroid_belt#Characteristics http://iau-comm4.jpl.nasa.gov/EPM2004.pdf
It's a very high "bang for the buck" mission.