NASA Researching Antimatter Engines

dbolger writes: "CNN has a story about how scientists at NASA's Marshall Space Flight Center in Huntsville, Alabama are researching ways to use antimatter to fuel missions to Mars and beyond within the next 50 years. It very light on technical details, but does give an interesting look at current and future potential uses of antimatter."

Comments

Re:Can you?

[hogsback]

yes you can.

Anti-protons (say) are just as real as protons and weigh the same. It's just that you have to be really careful because if an anti-proton meets a proton .... bang!

Re:Can you?

[KILNA]

Yes, but you need to be careful to only weigh it with scale made of antimatter. Or at least indifferentmatter.

That's why we would set up labs in space...

[silentbozo]

All the more reason to get our asses into space, so we can set up automated plants to manufacture anti-matter far away from inhabited areas...

Besides, free power (solar), free reaction mass (with sufficient heat, we can liberate volitiles from moon rock, asteroids, etc), and we're already outside of the gravity well... lots of advantages to doing space-related research, while actually in space. We just have to make like we want to stay there, instead of making very expensive vists all the time.

Cost (in energy) to produce

[jdavidb]

Am I the only one thinking antimatter costs more energy to produce than you get out of it?

A nuclear engine seems more practical for now

[Zergwyn]

When evaluating the usefulness of a potential fuel, one of the most important things is how efficiently that fuel can be converted to energy, and in engines the heat differential between the coldest and hottest parts of the system. Matter-Antimatter is very efficient, as there is direct mass->energy conversion. Combustion is very inefficient(a lot of burned fuel, not much energy).

Nuclear efficiency is in between. While there is not complete conversion, there is some mass going to energy, unlike in chemical rockets. However, nuclear physics is practical and well understood. A system would probably not work just as a bunch of bombs going off(though research was done on that, see The Binding Curve of Energy), instead liquid fuel, possibly liquid hydrogen or ammonia, would be sent through a nuclear core, then expelled. This would allow radiation release to be kept in check pretty easily, and a highly efficient super-heated plasma would propel the ship. In addition, unlike normal rockets the plasma could be controlled with magnetic fields.

While nuclear certainly holds a great stigma to many people, and is not as sexy as advanced antimatter/space warp/whatever systems, it is here and could be turned into a drive with minimal fuss. I could see a single nation/group(of sufficient economic strength, aka US, EU, possibly Japan) or coalition of nations getting behind this and making a ship to do it. The others will be needed, and research should continue, but if we want to go to other planets in the next couple of decades, this is probably the technology to do it with.

Antimatter in a nutshell:

[Nindalf]

Every known matter particle has an antiparticle which has identical mass, but opposite charges (for every kind of charge, including electrical). We don't know why, they just do. There doesn't seem to be much antimatter out there; again, for reasons unknown.

Antiparticles still have positive mass, like every other known particle, and are not repelled by gravity.

When a particle meets its antiparticle, they are converted into their combined mass worth of energy in accord with: E=mc^2 (where E is the energy, m is the combined mass, and c^2 is a ludicrously large number). Hence, antimatter is the most compact form of energy storage theoretically possible.

In other words, pretty good rocket fuel. Antimatter bombs would be rather unpleasant, and any contained antimatter is a potential bomb (there's nothing "potential" about uncontained antimatter for very long).

There is no reliable, efficient way of making antimatter, and no place to just pick it up for free. However, if you smash protons together hard enough with huge particle accelerators, they occasionally spit out highly energetic photons that decay into matched matter/antimatter particle pairs. With luck, you can catch a few in a magnetic field and hold them for a little while. This is about as cost-effective as it sounds.

If you ever meet your anti-self, and he hasn't exploded yet, either he or you will before you have a chance to shake his hand, so don't worry about it.

Despite this title, and the potential benefits of effective antimatter storage, antimatter can not be contained by a nutshell. Don't try.

Energy is only part of the problem.

[KFury]

The article, as written, is pretty shoddy, and looks similar to articles written 70 years ago touting how everyone would eat pills for food and fly personal jetpacks.

The problem that's not addressed in the article is that sure, antimatter is small, light, and excellent for storing energy with little mass, but what does that energy get you? Every spacecraft we've ever designed uses a reaction drive (and yes, solar sails are reaction drives too. They just use external sources as propellant.). The article doesn't address how we tackle the problem that for reaction drives to work we need to have something to throw behind us at high speed.

Not to say NASA isn't working on it. I'm sure they're looking at Bussard Ramjets or some other mechanism for using this tremendous energy to snare interstellar particles and throw them behind the ship. In fact, NASA has a few projects on the books for exploring exactly where the barriers between stellar and interstellar wind lay, and what the particle densities are really like. I guess this sort of detail is just too much for the average CNN reader.

The article, as is, doesn't provide any reason for being written now, other than a 'gee whiz the future's out there' fluff piece.

Hey, at least it's not about Afghanistan or weapons development.

Re:If I could have a $ for every NASA research....

[kEnder242]

It is impossible to tell if a program will stop (i'm assuming you are revering to the Church-Turing hypothesis), but it is not impossible to to prove that a program does its job (e.g. a loop for multiplication). If you take into consideration a machine with fewer states than a Turning machine (something finate, like a z80 with its 16 registers and a few k of ram) it is much simpler to prove program correctness.

Go take descrete structures again.