The Defense Department first proposed Star Wars. Now it wants Star Trek.

DARPA, the Pentagon's research agency that helped foster the Internet, wants someone to dream up a way to send people to a star.

The winner will get half a million dollars for the idea. This month 150 competitors answered the federal government's initial call for private sector cosmic ideas. Officials say some big names are among those interested. The plan is to make interstellar travel possible in about a century.

The Defense Department is known for big spending and big ideas. It devised a space-based missile defense system in the 1980s known as "Star Wars." Its new trademarked 100-year Starship Study concept comes from the Defense Advanced Research Projects Agency. The agency is spending a total of $1 million on the project. After presentations are made this fall at a conference in Orlando, Fla., DARPA will decide in November who gets the money.

The grant would be "seed money" to help someone start thinking about the idea and then get it off the ground in the private sector, David Neyland, director of DARPA's tactical technology office, said in a Thursday teleconference.

This isn't about going to a nearby planet, like Mars. And it's not about using robotic probes, which doesn't interest the Defense Department, Neyland said.

But even the nearest star beyond our sun is 25 trillion miles away. The fastest rocket man has built would take more than 4,000 years to get there. This isn't just about thinking new rocket methods, Neyland said. It's also about coping with extended life in space, raising issues of medicine, agriculture, ethics and self-reliance, he said.

Among those who showed an interest in the project earlier this year is millionaire scientist Craig Venter, one of those who mapped the human genome and is now working on artificial life and alternative fuels.

"We want to capture the imagination of folks," Neyland said.

Not everyone agrees with spending money this way. Steve Ellis, vice president of Taxpayers for Common Sense, said, "When you look at the universe - pun intended - of things we have to spend money on, this has to be pretty down on the priority list."

More information: DARPA's 100-year Starship Study: