It seemed like kind of joke last October, when the Pentagon wished out loud for a spaceship that would grab enemy satellites, and throw them around -- maybe even out of orbit. But the Defense Department is dead serious, the Arms Control Wonk tells us. $35 million serious.

In its proposed budget for 2006, Pentagon way-out research arm Darpa is asking for 35 large over the next two years for its Spacecraft for the Unmanned Modification of Orbits (SUMO) program.

"SUMO combines detailed stereo photogrammetric imaging with robotic... manipulators to autonomously grapple space objects," the agency says. "SUMO offers the potential for spacecraft salvage, repair, rescue, reposition, and debris removal to extend service life or provide a safe and calculated de-orbit."

Sounds friendly enough -- like a tugboat in space, maybe. Until you stop to think that the SUMO could also grab satellites that don't want to be repositioned or de-orbited. Suddenly, that tugboat starts looking an awful lot like a wrestler's arm, about to toss an opponent out of the ring.

THERE'S MORE: Of course, since this is Darpa we're talking about here, there are a whole smorgasbord of wild-sounding space projects waiting to be funded. Using "x-ray celestial sources to determine the three dimensional position... of orbiting spacecraft," anyone? Or how about space tethers, to "rapidly remediate high energy radiation particles produced by a High Altitude Nuclear Detonation?" A bunch of others are here.