Col. Jack Wassink is a former Marine Corps jet jockey with a weird new mission. This blunt, 45-year-old chief of the Marine Corps's tiny Space Integration Branch in Quantico, Virginia, shepherds the Marines' radical vision of space warfare.

Unlike the Air Force, Navy and Army, all three of which sponsor expensive satellite programs, the cash-strapped Marines are pushing just one space concept. It's called Small Unit Space Transport and Insertion, or SUSTAIN, and it's a reusable spaceplane meant to get a squad of Marines to any hotspot on Earth in two hours -- then get them out. The idea is to reinforce embattled embassies, take out terrorist leaders or defuse hostage situations before it's too late. "The Marine Corps needs [this] capability," Brig. Gen. Richard C. Zilmer told Congress in 2004.

"The Corps has always been an expeditionary force, a force of readiness, a 911 force," Wassink says. "All SUSTAIN is, is a requirement to move Marines very rapidly from one place to another. Space lends itself to that role."

Spaceplanes -- that is, craft that take off and land like airplanes but achieve low orbit using rocket motors -- aren't science fiction anymore. In 2004, Burt Rutan's Space Ship One snared the $10 million X-Prize by demonstrating that a relatively cheap and simple vehicle could get a man into low orbit in two stages and return him safely. Air Force Brig. Gen. S. Pete Worden said Rutan's bird offers a glimpse of a future military space transport. “It’s just a scaled-up version of that that would do this [SUSTAIN] mission."

This year, Defense Advanced Research Projects Agency, or DARPA, launched a spaceplane program called Hot Eagle. Capitalizing on Space Ship One and Hot Eagle, the Marines are hoping to get a space transport into service soon.

But Wassink says the Corps can't go it alone. He's been working hard since 2003 to convince the sister services and the scientific community to get behind SUSTAIN. "We've seen the entire gamut of reactions. Some people don't get past the past the giggle factor. Some people think we're off base. Some think we're visionary."

Wassink and the Marines are the underdogs of space. Of all the military space techs on the drawing board, SUSTAIN is the among hardest to pull off. "Propulsion and aerodynamics are going to have to be developed," Wassink says. "And there's a whole host of safety considerations. It's certainly not something the Marine Corps would be able to develop and acquire on its own."

But SUSTAIN promises, for the first time, the capability to influence events anywhere in the world fast and with flexible force, lethal or non-. Wassink believes it is truly revolutionary -- and possible in 10 to 15 years. That's why he's at the Pentagon or in research labs every week pitching SUSTAIN. And that's what motivates him to keep trying when skeptical scientists and generals laugh him out of the room.

"Think about how fast aviation developed. By the end of World War II, you're flying jet aircraft as opposed to propeller planes. That's just 20 years."

"It's realistic," Wassink says of SUSTAIN. "And I'm excited about it."