Why go all that way (to the asteroid belt) and back, and stop two doors down? Bring it into earth orbit! Or is that not politically correct? Because the risks are indistinguishable.
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.
Doing it at all is so near impossible at current technology levels as to be a pipe dream. To dream of putting further obstacles in our path is pointless.
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.
Hard? Its beyond our current level of civilization. We have projected only milliwatts to any distance beyond the moon. Moving asteroids proposes sending maybe terawatts. That's a lot of zeroes. Then propose autonomous robots to select an asteroid, navigate to it, attach to it, propel it and do course correction - aiming at good ol mother earth but trying to miss by a hair, with the biggest projectile mankind has ever launched.
Many other obstacles present themselves, but these two are huge enough.
> Its beyond our current level of civilization. We have projected only milliwatts to any distance beyond the moon.
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.
There are actually many peaceful uses of nuclear weapons, both the US and the Soviets experimented with using them to dig big holes, and the Soviets also used them for geographic surveys (like that "thumper" at the beginning of Jurassic Park, but much bigger ;)) and a few other things. Unfortunately all of these uses are politically untenable.
It would be great to use them in space though; it would probably be much easier to convince the public to go for that.
It would be bad, but it wouldn't really be that bad. A launch failure would not cause a complete detonation (that is trivial to prevent, but difficult to orchestrate). A fizzle could be mitigated fairly easily as well, possibly even by putting the warhead on a launch escape system if you really wanted to go overboard.
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.
Not really - bomb design has come a long way in the last ~70 years - modern bomb designs are very resilient to damage and very unlikely to detonate accidentally. And if that isn't good enough then take the parts to orbit separately and assemble in orbit.
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.
Nothing survives uncontrolled reentry. It isn't detonation that's at issue; its melted bomb parts falling like rain across large swaths of a continent.
Solar is definitely attractive - with the asteroid belt at triple the distance from the earth you'd expect n^2 reduction in efficiency ~10x, but without atmosphere you might end up about the efficiency of cells at sea level anyway. A solar sail kind of rig could be just the ticket.
In space, solar outperforms RTG on an energy-per-mass ratio until you get out past at least Saturn.
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.)
when someone at MIT recollected the requirements that NASA kept hidden regarding the computer that MIT was to designe for the apollo program, they said that their team would have dismissed it as technologically impossible at the time (the early 60s), and that it was the contractual obligation that forced them to come up with the ideas and technologies which were required for the flight.[1]
I don't disagree with you entirely, it is simpler to emulate an environment.
I'm not sure mining at the bottom of the sea is very analogous to mining an asteroid.
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.
Yeah they're different; the sea-floor one is lots easier. Remote control is in seconds not hours; spare parts are 5 miles away not 300,000,000. You can tether seafloor devices. Etc.
They're not going all the way out to the asteroid belt, 1999 AO10 orbits between Venus and just beyond Earth's orbit. As for the risks there's significantly less expensive equipment in Lunar orbit and the distance from Earth and Earth orbit would make an abort simpler.
I think you have a warped sense of what "politically correct" means. Just based on how many times I've seen misuse of the term from friends and people on the internet, I give it 90% odds that you're a Republican. :)
It can be done by robot, it several new abilities, it acts as a staging post for deep space missions, it lets NASA examine an asteroid close up and repeatedly, and it can be mined, again demonstrating abilities needed for deep space missions and for long-term possibilities for resource acquisition and management.
I think the second reason you listed to be much more compelling than the first. It could be argued that the space race was about ensuring that the US had missile superiority over the USSR, but I'd wager a significant number of the aeronautical engineers and astronauts involved were much more interested in going to the moon because it was there.
... and heck, it gives us a reason to go back to the Moon ... or at least, send more probes, etc, there, which themselves might help give more reason to go back to the Moon.
This is Step A, where Step Z is one of "save the planet from a world-killing asteroid" or "everyone gets a solid gold toilet" (or "a few people get solid gold toilets larger than the existing moon")
The earth doesn't have an unlimited supply of resources. Asteroids are literally loaded with minerals. At some point we are going to deplete the earth and will have to start looking to the skies to get what we need.
What are you on about? Limitless energy is rained down on us by the sun, and matter itself is conserved at the elemental level (barring nuclear processes, which are minimal on our planet). What do you suppose we are running out of?
Easily accessible resources. Yes, in principle everything can be converted into everything else if we pour enough electricity into particle accelerators, but in practice we have nowhere near enough power or time for that. Not until you get the nanotech working, at least.
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.
The Earth has far more minerals than the asteroid belt combined (its total mass is ~4% that of the Moon[1]). They're just buried under a lot of less interesting minerals. And there's some heat and pressure involved.
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.
Such work could help develop ways to use asteroid material for construction or spaceship fuels, making the captured asteroid a stepping stone for human missions to larger asteroids and eventually to Mars.
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.
They're not saying that we need to mine asteroids to go to Mars, more like the experiences and new technologies involved will add a great deal of value to all future missions, including any potential missions to Mars.
If you were designing a Mars mission, you would never put "let's go mine and process all of the necessary resources to construct our craft and equipment", either.
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.
once that technology becomes available and reliable,
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).
I thought artificial gravity was science fiction. Is that seriously being studied? I'm guessing they just are going to spin some kind of space capsule ala Space Odyssey 2001? What else would they be doing? Not generating any kind of artificial gravitational waves with a magical flux capacitor.
Spinning the craft is the easiest way. Spinning the craft around another craft that is tethered to it is better, though more difficult. Basically the tether gets you a longer axis, which makes it more comfortable for humans.
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.
> this isn't providing any of the key technologies we need for a manned Mars mission
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.
Nuclear rockets would be awesome. They aren't required for a Mars mission, and if we keep on talking about how much they would help, pretty soon they would implicitly end up on the "Required To Get To Mars" list. Then, any problems that nuclear rockets run into (say political opposition, reasonable or not) derails a Mars mission.
First off I have to admit I know practically nothing about this but wouldn't there be some very serious risks to doing this (Edit: If it's only 7m across I'm guessing it wouldn burn up in the Earth's atmosphere so probably poses limit risk to us in the form of an impact)? If there are it raises some serious questions about how humanity decides whether or not to allow NASA or any other space agency to go ahead with such a plan.
Things in lunar orbit do degrade and crash into the moon. NASA has put a lot of stuff into lunar orbit over the years and they all eventually crashed. There's essentially no atmosphere, but the Moon is not a perfect sphere and there are mascons that perturb orbits.
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 have to say, towing giant space-rocks around and getting them to follow a planned trajectory also sounds like a damn impressive weapon, if someone wants to use it that way.
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.
This is an old article (January 2013) and is very interesting, but substantially out of date regarding a story that has developed a lot. The concept, as indicated in the article, was developed by a KISS (Keck Institute) study group, which is a fancy way of saying about 30 scientists/technologists who gathered in a room at Caltech to think up some new mission concepts.
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...
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[ 2.8 ms ] story [ 109 ms ] threadHaving 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.
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.
http://en.wikipedia.org/wiki/NERVA
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.
[1] http://history.nasa.gov/computers/Ch2-2.html
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)
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.
________________________________
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.
[1] http://forum.kerbalspaceprogram.com/content/274
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.
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.
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