NASA Running Low On Fuel For Space Exploration 282
smooth wombat writes "With the end of the Cold War came warmer relations with old adversaries, increased trade and a world less worried about nuclear war. It also brought with it an unexpected downside: lack of nuclear fuel to power deep space probes. Without this fuel, probes beyond Jupiter won't work because there isn't enough sunlight to use solar panels, which probes closer to the sun use. The fuel NASA relies on to power deep space probes is plutonium-238. This isotope is the result of nuclear weaponry, and since the United States has not made a nuclear device in 20 years, the supply has run out. For now, NASA is using Soviet supplies, but they too are almost exhausted. It is estimated it will cost at least $150 million to resume making the 11 pounds per year that is needed for space probes."
Hm, an idea (Score:1, Interesting)
(I'm assuming this wouldn't be possible for gamma radiation, but alpha/beta radiation should be doable, as well as with simple residual heat)
Re:buy it from North Korea or Iran (Score:3, Interesting)
Re:Hm, an idea (Score:5, Interesting)
Given that nuclear reprocessing plants, such as Sellafield, supplied a lot of weapons material for the British nuclear program, I'd be astonished if these could not extract all of the plutonium needed from those fuel rods that have been recycled this way.
Alternatives? (Score:5, Interesting)
Research. (Score:5, Interesting)
Re:Hm, an idea (Score:1, Interesting)
Yes, however last time I checked that generated about 0.2 watts, which is beyond pitiful. You certainly need 200W to get a signal to earth, and probably more.
The problem is that the "waste" isotopes are too long-lived. It's not that they don't have energy, or that they don't radiate it out, but it takes too long (much like unenriched uranium : that's already been in the ground for about 3 billion years* and still not used).
* yes I know that's older than the earth is. That's because those isotopes were created the last time the sun went nova (or even 7 billion years old, the next-to-last time the sun went nova). They first existed in instellar cloud, then asteroid "ground", and finally earth ground.
The US has a source (Score:3, Interesting)
There is a source available. Just decommission a few nuclear warheads each year. Since the US has enough nuclear weapons [wikipedia.org] to basically end civilization, I suspect some could be spared without meaningfully degrading national security.
Re:buy it from North Korea or Iran (Score:3, Interesting)
(as a side benefit) the North Korean people will love us!
Joking aside, were it to happen, I believe that liberation of the North Korean people would open a massive can of worms.
Given that they've lived under an all-encompassing veil of propaganda and likely have a totally skewed worldview, can you imagine what would happen if the government fell and (e.g.) UN forces went in?
What do you tell these people? How will they react? How will you govern them?
Would it be necessary to exploit the existing propaganda machine to create the false impression that Kim Jong-Il is in power, gradually weaning them off their leaders over a period of years by pretending that these moves have been endorsed by their "beloved" leader and/or his "legitimate" successors until it converges with the real situation?
Of course, once they're truly weaned off the leader, the controlling forces would have to admit what had actually happened- a double mindfuck.
Re:buy it from North Korea or Iran (Score:2, Interesting)
Since when does the United States have money? I thought they went broke shortly after the second world war.
I am getting so moded down for this.
Re:buy it from North Korea or Iran (Score:1, Interesting)
Considering that North Korea has about 9 million people in it's army (1.2 in active service, 7.7 in reserve), I'd say the US would have a really hard time doing that. Not to mention what would China say to the whole idea...
Re:Not all plutonium is the same (Score:4, Interesting)
Sigh...
I really, really hope that was a joke. Because I'm sure somebody out there is going to assume it wasn't, and wonder why NASA doesn't just do that.
You can't "fission a few particles now and then". To establish the sort of chain reaction you're talking about in fissile fuel would require equipping the probe with a reactor. Ignoring the fact that people would scream bloody murder about launching such a device into orbit (it's been done before, but not recently, and not in this political climate), there are also technical limitations.
A RTG is not a reactor; it's something much lighter, with fewer moving parts. Doesn't generate as much power, but less power is needed if all you're running is a few sensor and communication systems. Even if we could make a reactor that lightweight, we couldn't make it go for decades at a time without maintenance.
So, to recap, we can't use Pu239 to power a RTG, and can't use a reactor to perform the same job. And we don't have very many isotopes that can fill the same role Pu238 does.
Plus, any fancy new solution would surely cost more than the $150 mil mentioned in TFA, making the question moot to begin with. Compared to the cost of developing, testing and building a next generation fission reactor that will run for decades sans maintainable, a few hundred million dollars is a drop in the bucket.
Re:buy it from North Korea or Iran (Score:3, Interesting)
The difference between the USA and North Korea is that North Korea is as close to a perfect example of a totalitarian state as has probably ever existed. The state is everywhere, in every aspect of its citizens' lives, to the point where they have internalised it. (Witness, for example, reports from the train explosion in the north of North Korea a few years ago, which stated that many citizens perished going back into their burning houses to rescue their portraits of Kim Jong Il, and imagine, for a moment, what sort of psychological conditioning could make people behave in this fashion.)
If/when the regime collapses, a lot of North Koreans are going to have an extremely hard time adjusting. There will be chaos and hardship, and a lot of North Koreans will pine for the "good old days" of the regime, in the way that East Germans and Russians do, only more so. In short, things are going to get quite fucked up.
Re:Research. (Score:2, Interesting)
Oh yeah, let's just do that. Hmmm, what kind of energy sources exist in space? There's the sun, but we are too far away from that...There are gravity sinks so I suppose we could use some of the orbital energy and convert it to electricity. Of course then our rate of travel decreases and the mission life extends and we need more energy. There is some free-floating radiation out there so maybe we could use the surface charge on the spacecraft and convert it to electricity, except oh hmmm, that tends to screw with the electronics inside the spacecraft...There is of course a lot of matter between vacuum areas (odd way of phrasing it), maybe we could make a rock eater that breaks chemical bonds to generate electricity. Oh wait, that involves an extremely complex mission segment dedicated to a rendezvous/intercept coupled with a departure which involves changing flight path, increasing mission complexity, and then, oh yeah, increasing energy needs. Maybe we should find a way to carry energy with us. Let's explore that path....
We could use batteries, but then of course they have a lifetime and cycle limit associated with them that is extremely small compared to nuclear power sources. It doesn't help that they add one metric $hit-ton of launch weight which drives costs through the roof. It also doesn't help that they add a large mass sink in your spacecraft that makes controlling the dynamic and static states of the spacecraft a veritable nightmare...We could put an internal combustion engine on the spacecraft...oh wait, no air. Well what about a solar reflector that focuses sunlight and forces a steam-turbine...oh, yeah, we are too far away from the sun. Let's see, what is a good way to bring energy to deep space? Isn't there some sort of element or material that has a naturally high energy that is just waiting to release that energy in the form of heat to generate electricity? Oh yeah! It's called a radioactive material....we should use that.
No? Okay, well organic lifeforms store a lot of energy, lets just strap some chimpanzees in the pilot's seat and power the spacecraft off their silly monkey antics. Better yet, let's invent a puppy-combustion engine and just pack all of the chihuahuas in the world onto the spacecraft....
Don't get me wrong, I am all for innovation and as soon as we figure out a better method of power-generation for deep space missions, we should jump on it like slashdotters on a flamebait thread. However, at this point, nuclear power really is the ONLY reasonable means to power deep space missions. Coming up with alternatives takes a hell of a lot of imagination, time, and money that, well, scientists and engineers are not being given these days. Please, take it from an aerospace engineer that has specialized his degree in spacecraft power systems, nuclear power generation is the most efficient and useful means of generating power in space. For deep space missions, this method is necessary and will remain so for quite a while. If you or anyone else can come up with something better, please do, but for now, sidelining nuclear-powered spacecraft will bring deep space exploration to a grinding halt.
Cheers.
Re:buy it from North Korea or Iran (Score:2, Interesting)
I agree with the +5 but I'm unclear why parent post is mod'd as funny.
Anyways, if the ban on reprocessing is not repealed, it is still legal to send out US supplies for reprocessing to foreign countries, such as Japan. The international law is that such material must return to home country. You get your plutonium back, plus the unrecylable stuff, which just goes in dry casks anyways to sit next to un-reprocessed stuff onsite.
I'm very confused why this would cost anywhere near $150 million, since several allies already have reprocessing plants running. Even the UK, which I believe shut down or is shutting down their reprocessing efforts, likely has excess plutonium they will likely never use.
Re:sounds pretty bogus (Score:3, Interesting)
Solar will not work well past the orbit of Mars
Actually, NASA is building a Jupiter space probe now called Juno [wikipedia.org] that uses solar panels. Quoting the article:
Advancement in solar cell technology and efficiency over the past several decades now makes it economically feasible to use solar panels of practical size to provide power so far from the Sun.