The scoop: Antimatter is a Star Trek favorite when it comes to imagining future spacecraft technology, but how far off are scientists from the real thing?
We chat with George Schmidt, who dabbled in antimatter-powered spaceship concepts before becoming the Deputy Director of Research and Technology Directorate as NASA's Glenn Research Center in Cleveland, Ohio.
Dave on Earth (2:01 PM): Hi Dr. Schmidt!
Antimatter George (2:07 PM): Hi Dave. How's it going?
Dave on Earth (2:08 PM): Great - starting to get nice and toasty in the heat island that is New York City. How is it at NASA Glenn Research Center in Cleveland?
Antimatter George (2:09 PM): Temperature has dropped a lot today… Yesterday, we were in the mid-80s. Now it's just pushing 60, and lots of rain.
Dave on Earth (2:09 PM): Yuck.
Well, a perfect day on both ends to sit indoors and chat about antimatter!
I'm guessing you've heard about the Angels & Demons movie coming out?
Antimatter George(2:10 PM): Yes, I have.
I read the book about 2 or 3 years ago, right after the Da Vinci Code came out.
Dave on Earth (2:11 PM): Excellent - so it looks like you're a budding Dan Brown fan.
I ask about Angels & Demons because at the core of the plot is an antimatter bomb -- that's not your, um, field of research -- but I have heard that you've done some work with antimatter spaceship concepts?
Antimatter George(2:13 PM): You are correct.
We weren't working on any type of weapons applications, that's for certain!
Our team had a pretty active effort looking into how we might apply the immense energies available from antimatter/matter annihilation. In other words, for propulsion in space.
Dave on Earth (2:14 PM): You said "had a pretty active effort." What was the effort called, and is it still going on?
Because I'd like my antimatter spaceship ready for departure next week, thank you very much.
Antimatter George(2:17 PM): We started these activities around 1997 under the auspices of NASA's former Advanced Space Transportation Program.
These efforts continued under various versions until 2005 or so.
Dave on Earth (2:19 PM): What did you set out to do?
I like to categorize our activities into three basic areas: production of antimatter, storage and use.
Most of these work on the NASA side, at least, has been discontinued due to the shift in agency priorities.
But there are still some groups outside of NASA that are pursuing this type of work. Mainly in storing antimatter.
Dave on Earth (2:23 PM): Thanks.
The groups outside still working on storage -- what's the status there?
Clearly I can't pick up an antimatter collector at a hardware store yet, but...
Antimatter George(2:25 PM): None of those yet, that's for certain!
The one group I've best stayed in touch with wants to use the antiproton trap that we at NASA helped develop. It would collect and store antiprotons produced at the Dept. of Energy's Fermi National Laboratory in Batavia, IL.
The intent here is to use the device -- which can store up to a trillion antiprotons -- as a portable system for use in commercial applications.
Dave on Earth (2:26 PM): Commercial applications?
Antimatter George(2:27 PM): Right. One very appealing idea is the use of antiprotons in cancer therapy, as a means of precisely destroying tumors.
Dave on Earth (2:29 PM): Wow. And you also threw out a number up there -- a trillion antiprotons…
How far in space might that get a spaceship?
Or is it a case of it sounding like a lot of antimatter, but in truth is a tiny, tiny amount?
Antimatter George(2:40 PM): Actually we are talking about a very very small amount, at least from a mass standpoint.
A trillion antiprotons has a mass of about 1 picogram -- or one trillionth of a gram. This is way too small for any of the "conventional" antimatter propulsion techniques, where antimatter meets matter as the sole source of propulsive energy.
We were more interested in using antimatter to promote nuclear reactions, mainly nuclear fission and fusion.
Some research in the 1990s showed us all that antiprotons can induce some interesting new types of nuclear activity able to initiate fusion. That's a powerful process, and very appealing for space propulsion.
We found that -- with some development to current antiproton production -- we could produce antiprotons in amounts where propulsion applications begin to look halfway plausible.
Still talking miniscule amounts from a mass standpoint, but… you don't need much antimatter.
Dave on Earth (2:42 PM): Hmm... so how much antimatter might I need to get to Mars and back?
I talking a ball-park estimate here.
Antimatter George(2:49 PM): Let me give you some numbers:
Using a concept that we referred to as "Antimatter Catalyzed Microfusion" (or ACMF, for short), we could perform a "fast" roundtrip mission to Mars with a 110-ton payload using about 1 microgram of antiprotons.
This is about 1,000 times the amount produced annually in the world today(!).
However, as I said before, with some improvements in production infrastructure and efficiency, we could probably achieve this number.
Dave on Earth (2:50 PM): So it's not unreasonable to say that we may have antimatter spaceships in the near future?
I mean, what is preventing us from having them? Is there too much radiation produced? Still a lot of technology to prove? Antimatter George(2:57 PM): I wouldn't say "near future," because many of these ideas are still very conceptual and require much more research to evaluate. Also need to mention that almost all of the energy used in the ACMF concept comes from fission and fusion, so the basic physics of these interactions with antiprotons must understood to a much greater level. That said, there are many rather daunting technological challenges that have to be addressed with basic research. One is the storage problem. Storing even a microgram or two of antiprotons will require completely new methods. Otherwise the antimatter will react with the storage vessel and systems, and... boom! Another is how we design a propulsion system so that it provides the performance we need to take on ambitious missions. Dave on Earth (2:58 PM): Lots of work to do! My last question for you: Would you ever ride in an antimatter-powered spaceship if you had the chance? If so, where would you go? Antimatter George(3:00 PM): Certainly. I think Mars -- the destination you mentioned -- would be great. Perhaps with more development, we could eventually use antimatter for interstellar travel. However, this is going to take a lot of work and a lot of antiprotons! Dave on Earth (3:01 PM): So you would really risk hitching a ride on an antimatter-powered spacecraft? Antimatter George(3:02 PM): Sure, but it better not be a one-way trip! Dave on Earth (3:02 PM): Thanks Dr. Schmidt -- really appreciate you taking the time to chat! Antimatter George(3:02 PM): It was a pleasure. Thanks!