NASA Working on a Tractor Beam
For those familiar with science fiction stories and some video games, the concept of a tractor beam is old news. At NASA though, there is real science being considered to put tractor beams on a variety of future missions, though these will not be like the Excursion Funnels of Portal 2 (well, not entirely). The hope is to use beams of light to collect samples from the ground around rovers and other landers, as well as from the space and atmosphere around satellites. There are already three possible techniques scientists could use to achieve this; optical tweezers, solenoid beams, and Bessel beams.
Optical tweezers can hold a particle at the focal point of a laser while the solenoid beam will pull a particle towards the light source. Both of these techniques have been tested, but Bessel beams have not yet. While normal laser beams leave a dot, a Bessel beam will leave a pattern of bright and dark rings, like a ripple in water. This third technique, like the solenoid beams, would pull a sample along the light beam, to the source.
Currently the research is at the stage of collecting ideas, and eventually 30 will be selected for initial funding.