NASA is working on what some in the media call a "tractor beam" named after the famous technology in "Star Trek" that the USS Enterprise used to grab and tow other objects in space, including other star ships.
The NASA version will not be quite that powerful.
What is NASA looking for in a tractor beam?
NASA would like to develop technology that would enable future space probes to capture particle samples, say from an asteroid or a comet, and bring them back to Earth to be studied in a laboratory.
How would the technology work?
NASA is looking at three possible technologies to develop a particle collecting tractor beam. They are:
An optical vortex beam that would consist of two beams of light that would create a ring structure that would trap particles to be delivered to the space probe. The device would heat air around the particles to move them up the beam to be collected. Unfortunately this method would not work in the vacuum of space. It could possibly be used on a planet such as Mars to take small soil samples.
An optical solenoid beam that would that would manipulate magnetic and electrical fields to drive particles toward the source of the beam. The beam creates peaks of intensity around the middle of the ray, sort of like a spring made of light. This particular technology was recently discussed in a paper in optical express. This method would not require an atmosphere to work and thus could be used to sample asteroids and comets. .
A "Bessel beam" that would create a ripple effect that would also manipulate magnetic fields to move particles in any direction desired. Unlike ordinary lasers, according to i09, a Bessel beam creates a tiny dot surrounded by concentric circles, like a bull's eye. Right now they are used to manipulate living cells.
How is NASA proceeding in developing tractor beam technology?
The first step is a $100,000 grant to investigate which of the three methods would be most suitable for developing a tractor beam. After that, a prototype would be developed and presumably tested on an actual space mission.
Could a true tractor beam capable of moving large objects ever be created?
According to Discovery Magazine, a Star Trek-style tractor beam seems to be one of those technologies, like warp drive or transporters, that are rather far off, based as it is on physics that are either as yet undefined or at least dimly understood. That is not to say that such a device will never be developed. But such are a long way off.
Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times and The Weekly Standard.