Slashdot Mirror
NASA Plans To "Lasso" Asteroid and Turn It Into Space Station
SternisheFan writes "NASA scientists are planning to capture a 500 ton asteroid, relocate it and turn it into a space station for astronauts to refuel on their way to Mars. From the article: 'The 1.6bn-pound plan will be considered by the White House's Office of Science and technology in the coming weeks, as it prepares to set its space exploration agenda for the next decade, the Daily Mail reported. According to a report prepared by NASA and California Institute of Technology (Caltech) scientists, an, 'asteroid capture capsule' would be attached to an old Atlas V rocket and directed towards the asteroid between the earth and the moon. Once close, the asteroid capsule would release a 50ft diameter bag that would wrap around the spinning rock using drawstrings. The craft would then turn on its thrusters, using an estimated 300kg of propellant, to stop the asteroid in its tracks and tow it into a gravitationally neutral spot. From here space explorers would have a stationary base from which to launch trips deeper into space. Though NASA declined to comment on the project, it is believed that technology would make it possible within 10-12 years. The technology would also open up the possibility of mining other asteroids for their metals and minerals. Some are full of iron which could be used in the making of new space stations, others are made up of water which could be broken down into hydrogen and oxygen to make fuel. It is hoped that the project will increase our understanding of asteroids, and even shed new light on the origin of life on Earth.'"
"... the Daily Mail reported." All i have to say
What could possibly go wrong?
"a space station for astronauts to refuel on their way to Mars"
I hope they hire Andy Libby to do their calculations.
Anyway having a "gas station in space' is not that good unless you just have it in Earth orbit. Having one halfway to mars is not going to work because you would have to slow down to dock with it and waste delta V
The idea is to use energy when you are close to the sun, where photovoltaics are practical. The stored energy is then used when you are distant from the sun, where photovoltaics are not practical.
Look up Lagrange points for a "neutral spot".
Hand in your nerd card at the exit.
1. Use a Raspberry Pi convert the DXF file into g-code
2. Send the g-code to an Arduino to control the motors of your 3D printer
3. Use the spare cycles of the Raspberry Pi to generate bitcoins.
4. Marketing profits!
Get free satoshi (Bitcoin) and Dogecoins
People keep touting the idea of mining metals from asteroids and using it to build spacecraft outside of the earth's gravity well, but do we actually know how to do that?
The mining side of things seems relatively straight-forward (not easy, but you wouldn't need anything radically new), but smelting and refining significant amounts of ore in low gravity could be rather difficult. As far as I understand, a traditional iron smelting plant uses gravity to help with the purification, allowing the slag to float to the surface, before tapping the good quality iron from the bottom of the blast furnace.
It seems like purifying and working ore in space would require entirely new ways of working with the raw materials. Perhaps using some kind of high temperature centrifuge to spin and separate the material.
I'm not saying it's not possible, but it doesn't seem quite as easy as some of the more excitable science-fictiony plans for space exploration treat it. Many of these plans feature major problems to solve that get glossed over as minor technicalities.
Paul Leader
and when they launch to another planet from the asteroid, it will be kicked out of its "neutral" orbit and enter a declining apogee which eventually causes it to crash into Earth.
boy, I hope that colonization thing works OK
if this is supposed to be a new economy, how come they still want my old fashioned money?
Here is the link to the pdf download at California Institute of Technology: http://www.caltech.edu/search/sites/asteroids%20nasa#gsc.tab=0&gsc.q=asteroids%20nasa&gsc.page=1
The energy to split apart hydrogen from oxygen in water always exceeds or equals the energy received by burning the hydrogen. Welcome to physics.
Yes, but hydrogen and oxygen are more useful as rocket fuel than sunlight, electricity, or water. Plus, the rocket that's to be refueled doesn't have to haul the water, fuel, or energy to the refueling point. Welcome to engineering.
Also, they're going to tow out a bunch of fuel and supplies, let's say halfway to Mars. Then they're going to launch a 2nd spacecraft and stop there to go get it. I have an idea. How about they put all the supplies on the first spacecraft instead and don't make a pitstop then just deal with the extra weight, which sounds easier than lassoing an asteroid.
Great idea. I bet the people at NASA have never thought of your "build a bigger rocket" solution.
And you know, NASA doesn't have anyone who understands basic thermodynamics or orbital mechanics. [rolls eyes]
Other posters have already pointed out the specific problems with what you wrote, but what bugs me more about this post, and the thousands more like it, on just about any story dealing with any scientific topic, is the inherent assumption that some random dude on /. has seen an obvious logical hole that the people whose job it is to study the subject every day for years have missed, usually based on said random /.er's half-remembered high school "science class" or undergrad Physics 101 class. Now, this is certainly possible--in all fields, amateurs sometimes see things that the professionals miss--but it's really not the way to bet.
Try thinking before you post. Just give it a shot sometime. You might be surprised by the results.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Yes, the Trojans are at two of the Sun-Jupiter Lagrange points, where the gravity from each of those bodies is balanced, more or less allowing small objects to remain there.
Similar points exist between the Earth and the Sun and between the Earth and the Moon. Three points lie along the axis of the two bodies, and two lie in the orbit of the smaller body, 60 degrees ahead or behind.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
I see an obvious logical hole in your post in that this is from the Daily Mail and NASA refused to comment on this entire plan or new story. They probably think it's as stupid as I do.
Storing H2 is a massive pain in the ass; it leaks out of the tank, the atoms are so small. There are other problems with it too. Better to combine it with carbon to make methane and only crack it to get the desired liquid hydrogen shortly before you plan on using it.
That having been said, I'd rather use electric propulsion using oxygen as fuel (it's much more practical) whenever possible. Carbon monoxide & oxygen is lousy but can be made from the Martian atmosphere. Aluminum & oxygen is also lousy but can be made from lunar rocks and soil.
Hydrogen that is convenient for use in space by us without amazing science fiction technology is fairly rare. Helium too, which is important stuff to use in conjunction with hydrogen (it helps to push the fuel into the engine).
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
These aren't the roids you're looking for.
Escher was the first MC and Giger invented the HR department.
Energy is energy. Put the solar energy into an engine like an ION thruster and it'll be more efficient than making hydrogen.
You can't put light in a box and store it on a rocket. You can't even put electricity in a box and store it on a rocket, you need some way -- usually chemical -- of storing the energy. Rocket fuel is pretty efficient in that regard. An ion thruster ("ion", not "ION") uses electricity, so it would only really be worthwhile if you have the solar power generation on the rocket. Except using solar power to drive a rocket is really slow, which creates its own serious engineering problems. Splitting water, you can concentrate years' worth of solar energy into a portable fuel.
The fact that all forms of energy are not equally-useful is one of the reasons we're not all driving electric cars and flying electric planes.
nuclear engines work wherever you are
Except in space, they have nothing to push against. You have to shed mass, preferably at high velocities, to move a rocket. That mass is fuel, whether combustible or not, and it tends to run out. (Nuclear power plants also are a bit on the complicated side. There are nuclear power sources that are uncomplicated -- RTGs -- and they already use these in satellites. They provide very little power, though.)
That's what I got too, but if that's the case it seems like a bad idea to me. The L1 (and L2) points are unstable, like trying to balance on the edge of a knife - the Moon and Earth are both "down", and you've got a 50/50 chance that when it destabilizes it'll be on a collision course with Earth. Now I suppose you could put it in one of those complicated 3D orbits around the L1 point like they do with the solar observer at the Earth-Sun L1, but that still requires constant minor momentum adjustments which could add up fast for a 50 ton mass. Especially with the sun's gravity constantly upsetting the pseudo-equilibrium.
I would think the Earth-Moon L3 or L4 "points" would be far more attractive since they are gravitationally stable so you don't have to be constantly fine-tuning your momentum. Granted though, they are at a considerably higher specific orbital energy than the L1 point, high enough even that it's easier to escape the Earth's pull entirely than to match speed with them. And perhaps NASA is looking ahead and thinking having a space station at the L1 point would be an asset towards eventually building a lunar space elevator, which would be an enormous asset towards colonizing/mining/etc the moon and quite feasible with current materials, unlike an Earth elevator. There might also be some strategic thinking involved - the L1 point is uniquely valuable, and whatever nation controls it will be well positioned for many future endeavors.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
You see, in another four years, a new president will take over. This president will decide that they want to leave a legacy through NASA, as all the proceeding presidents since Kennedy have (all wanting to share in some of that immortality), and blow up Obama's plan for this new presidents plan. Just like Obama did to Bush (remember we were going back to the moon a mere 5 years ago!) and as I'm sure Bush did to Clinton and Clinton to Bush and Bush to Reagan and Reagan to Carter and well you get the idea.
It's like the pharaohs of ancient Egypt; when the last one dies you either deface his monuments and put your name up there or you outright destroy them.
No progress to be made here!
Wow, a whole 300 kg of propellant. I am impressed..
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Even that's not hard, just really, really expensive when the fuel costs upwards of $100/kg just to get it into orbit. On the other hand if you can produce it cheaply in orbit from materials that have never set foot on Earth, and send a refueling pod drifting on a multi-year low-energy trajectory to a Mars parking orbit so it'll be waiting for the primary mission, it'd be a LOT cheaper.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
t is hoped that the project will increase our understanding of asteroids.
Nice editing, found two mistakes on a quick read.
Agreed. "T" should be capitalized and be preceded by Mr.
I don't know how you got onto /. without knowing what a Lagrange Point is, but yeah it's more-or-less gravity neutral there. (More so at L4 and L5 than the others, but in any case you need only minimal fuel for station keeping.) And that makes it a good place for a fuel depot. In fact, it's better than refueling in LEO if you're using fuel mined from asteroids, because you need less fuel (on average) to get that fuel to L5 than to LEO. And the reverse is true as well... In order to refuel along the way you need to get either the fuel to LEO or the spacecraft to L5, and it's probably a lot more economical to do the latter than the former. (Depends on the mission of course, but for Mars, definitely.)
Personally, I'm just happy to see NASA looking at long-term plans that aren't focused on a BTDT "flags & footprints" mission with no follow up. Turning an asteroid into a space station is a good idea, and a major step toward robust space infrastructure. Ultimately I reckon the bulk of this work will be done by private industry, but it's good to have NASA get out in front of this trend. Even just announcing this plan will get private-sector resources working on it. (What they should do is offer an open 5-year contract for fuel delivery at L5 at, say, 1-10/th their cost of launching it from Earth.)
Even just setting up an outpost there at L5 would create a "demand pull" toward supplying its needs. The nascent "NewSpace" industry is champing at the bit, waiting for this sort of opportunity. A reliable commitment from government would go a long way in this sector.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Put the solar energy into an engine like an ION thruster and it'll be more efficient than making hydrogen.
Do you know what an ION is? It's a charged particle. PARTICLE. ION thrusters work by accelerating a mass of material away from the craft, they don't run on pure sunlight. The infrastructure to mine and harvest the gases we use to propel out of the relatively weak ION thrusters is many times greater than the facilities needed to produce hydrogen and oxygen from water to create a much stronger thrust per fuel mass. You've essentially ignored compression of energy density over time and said, "Why don't we just use solar cells to power cars directly?" Derp!
That's because:
0. It's half way to our moon, not to Mars.
1. It's sort of like golf. It takes much less precision, force, and skill to make a closer target first than to get a hole in one.
Think of it like this: You spend a bunch of fuel getting out of Earth's gravity well, but taper off and just gently break free, glide up to the refueling station, dock, take on the rest of the fuel you'll need, and go from there, avoiding having to carry that fuel out of the strong part of Earth's gravity well. I agree it would be better to equip cars with a huge 10,000 gallon fuel tank that would last the car's expected 200,000 mile life span, so they'd never stop for refueling or run out of fuel unexpectedly, but there's this thing called inertia... What if... What if you never ate once you left your parents and went out on your own? Imagine how much fat you'd have to store to live another five decades off of it. See? It's only natural we make pit stops. Cyclic actions are intrinsic to life not because our planet spins, but because they're more efficient.
They're doing the same thing, but it's a private company. And they're hiring.
Help stamp out iliturcy.