NASA Pursuing 'Tractor-Beam' Technology to Gather Samples

From PCMag.com: NASA Pursuing 'Tractor-Beam' Technology to Gather Samples
Science fiction and real science could converge if a NASA-funded study of "tractor beams" that could be used to trap and gather material in space bears fruit. The U.S. space agency has committed $100,000 for the Goddard Space Flight Center to study three different methods of using lasers to gather samples on future space missions.

"Though a mainstay in science fiction, and Star Trek in particular, laser-based trapping isn't fanciful or beyond current technological know-how," said Paul Stysley of the group in the NASA-run Goddard Space Flight Center that was awarded the research funding, according to Space.com.

NASA had originally been investigating "tractor beam" technology as a way to clean up the space junk in Earth's orbit that poses a problem for orbiting satellites and spacecraft.

"But to pull something that huge would be almost impossible—at least now," said Stysley, a laser engineer. "That's when it bubbled up that perhaps we could use the same approach for sample collection."

Instead of capturing large objects like the space debris in Earth's orbit, NASA now hopes to use laser-based trapping to capture much smaller particles in space for analysis.

Stysley said his team was eying the technology as a way for automated rovers and orbiting spacecraft to gather samples from Mars' atmosphere, and for deep-space probes to collect particles beyond the reach of their robotic arms.

The three approaches for using lasers to trap samples are employing a set of "optical tweezers," a more tractor-beam-like method using optical solenoid beams, and a third, as yet untested technique using a "Bessel beam."

The tweezers method would utilize two overlapping laser beams going in opposite directions to create a ring that traps particles, according to Space.com. The particles would be drawn back towards a waiting probe by changing the intensity one of the beams relative to the other.

That method is geared for sample collection in a planetary atmosphere, while the use of optical solenoid beams capable of pulling particles back along their length would be more suitable for deep space missions.

The "Bessel beam" technique involves scattering laser light, which would theoretically "create electric and magnetic fields in the path of a particle that pull the object backward against the beam's own movement," according to Space.com.

NASA's current methods of sample collection—which include the traditional use of scoops, scrapers, and robotic arms but also a material called aerogel used to trap samples in the outer atmosphere of comets—could eventually be supplanted by the laser-based methods now being studied, 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," he said. "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."