NASA developing tractor beam

NASA researchers are exploring the possibility of tractor beams. The scientists are studying several methods for grabbing planetary or atmospheric particles in a laser beam for transfer to an instrument that would analyze their composition.
"The original thought was that we could use tractor beams for cleaning up orbital debris," (principal investigator Paul) Stysley said. "But to pull something that huge would be almost impossible — at least now." That's probably ok because the old man would get that tractor beam out of commission anyway. From NASA:

 Images Content 599813Main Rover

Currently, NASA uses a variety of techniques to collect extraterrestrial samples. With Stardust, a space probe launched in 1999, the Agency used aerogel to gather samples as it flew through the coma of comet Wild 2. A capsule returned the samples in 2006. NASA's next rover to Mars, Curiosity, will drill and scoop samples from the Martian surface and then carry out detailed analyses of the materials with one of the rover's many onboard instruments, including the Goddard-built Sample Analysis at Mars instrument suite.

"These techniques have proven to be largely successful, but they are limited by high costs and limited range and sample rate," Stysley said. "An optical–trapping system, on the other hand, could grab desired molecules from the upper atmosphere on an orbiting spacecraft or trap them from the ground or lower atmosphere from a lander. In other words, they could continuously and remotely capture particles over a longer period of time, which would enhance science goals and reduce mission risk."

"NASA Studying Ways to Make 'Tractor Beams' a Reality" (Thanks, Ariel Waldman!)