I recently stumbled on the online Straight Dope and, since you seem to be the guru of all things, decided to ask a question. How many years ahead of us is DARPA, technologically, and what secrets do you think they may be hiding from us? — A curious kid

P.S. Do you think a rail gun would be a winning science fair project?

A rail gun, huh? Kid, send me your resumé when you get older. We may be able to use you on the team.

DARPA, the Defense Advanced Research Projects Agency, is the U.S. defense department’s R & D arm. It was founded in 1958 to help the country compete in the space race after the Soviet Union launched Sputnik, but its mission changed a year later when most of its space operations were spun off to form NASA. The agency didn’t drop all the rocket stuff, though. It worked on ballistic missile defense and created the Vela program, which used satellites to verify that the Soviet Union was adhering to the 1963 nuclear test ban treaty. DARPA branched out into weapons development during the Vietnam war and since then has gotten into a wide range of military and general scientific projects.

DARPA is known for its commitment to unorthodoxy<emdash>no concept is too far out. It doesn’t run big labs but rather farms out projects to universities and private corporations. With its decentralized approach, minimal management structure, and willingness to hire just about anybody with a good idea, it’s has been described as “100 geniuses connected by a travel agent.”

And they’ve definitely pushed the tech envelope. The most famous DARPA brainchild is almost certainly an early computer network called ARPANET, created to facilitate collaboration among industry and university researchers. That was the beginning of the Internet. DARPA-funded researchers anticipated Google Street View by 28 years with their Aspen Movie Map, a 3-D walkthrough of Aspen, Colorado. Other DARPA research explores unintended uses for existing technology.

Last year the agency examined social networking as a high-speed information conduit with its Network Challenge, in which contestants were encouraged to use sites such as Facebook and Twitter to locate ten giant red balloons tethered around the U.S. Displaying the instinct for simplicity that marks true genius, the winners, a team from MIT, completed the challenge in less than nine hours by offering cash bounties for balloon info.

While those projects were out in the open, much DARPA work understandably is done on the QT. The Sea Shadow, a radar-resistant ship that looks like a floating stealth fighter, was built in the early 80s and operated in secret till 1993. The reusable unmanned spacecraft known as the Boeing X-37<emdash>a NASA project taken over by DARPA circa 2004<emdash>was successfully launched into orbit in April. Resembling a miniature space shuttle, the X-37 has inspired plenty of speculation about its intended role: Advanced temporary satellite? Satellite repair vehicle? Mobile weapons platform? The air force isn’t saying much.

DARPA has had its share of flops and boondoggles. The 9/11 attacks prompted a couple: (1) an Information Awareness Office, which would have snooped into everything from medical records to e-mails without a search warrant looking for terrorists, and (2) a IAO offshoot called FutureMAP, designed to harness the power of the free market to predict terrorist activity<emdash>essentially an online futures-trading game allowing the public to bet on when and where the next attack would occur. Both programs were killed after Congress squawked, although some IAO projects were just transferred to other agencies. (And between you and me, FutureMAP was nowhere near as nuts as it sounds.)

DARPA also spent years trying to develop a futuristic super bomb using the metal hafnium that could double as a power source for Strategic Defense Initiative lasers. Based on the irreproducible results of some Texas researchers who claimed they produced gamma rays using a dental X-ray machine and a styrofoam cup, the project was ridiculed by the scientific community as contrary to the laws of physics and wound up wasting tens of millions of dollars.

I promised I wouldn’t spill about DARPA’s most secret ongoing projects, so I’ll have to disappoint you there. But even the ones that have been made public sound like science fiction:

— Implanting circuits into beetles to remotely control them.

— Powered armor exoskeletons for infantry, as envisioned in the 1959 Robert Heinlein novel Starship Troopers, the Iron Man movies, etc.

— Flying cars. Yes, we’ve been hearing about these since roughly the time the Cubs last won the World Series. Hope never dies.

DARPA’s 2010 budget request lists hundreds of projects totaling just over $3 billion, peanuts compared to the overall defense budget of nearly two-thirds of a trillion dollars. But cost doesn’t correlate with coolness. Take powered armor — if I weren’t on the phone all day with Orszag, BP, and those guys, I’d work on that one for free.

As to whether your rail gun would win the science fair, I’d say that would depend where you pointed it, wouldn’t you?

This article appears in Jun 2-8, 2010.