Laser 'tractor beam' for astronauts being developed

The tractor beam, a staple of many popular sci-fi programs, is moving closer to reality, though not in the way the shows’ producers imagined. Scientists are working on a system where a laser can vaporize small thrusters mounted on a spacesuit to push an errant or incapacitated astronaut back to safety, New Scientist reported. John Sinko, an engineer at Ohio State University who originally thought of the system to de-orbit space junk, is now developing a prototype device along with Clifford Schlecht at the Institute for Materials, Energetics and Complexity in Greenville, South Carolina. Using their theory, a carbon-dioxide laser can be pulsed on a one-kilogram thruster for 200 seconds to move an astronaut towards safety at one meter per second. But they warn great care must be taken to avoid accelerating the astronaut too much that they could be injured. “While this looks kind of quirky and wacky, you never know - there just might be something in it," New Scientist quoted Richard Holdaway, director of RAL Space, the space division of the Rutherford Appleton Lab near Didcot, UK, as saying. The New Scientist article said Sinko’s plan is to have spacecraft carry thrusters with two types of propellant, each responding to a different laser wavelength. A laser beam shone on the thruster vaporizes the propellant to create thrust, thus pushing the spacecraft. The propellants fire in different directions, allowing the spacecraft to be steered. Sinko and Schlecht theorized such a system can help retrieve a spacewalker who is floating helplessly in space. In contrast, existing rescue systems use spring-loaded or gas-driven tethers that can be fired towards an astronaut, but cannot reach more than 100 meters. Also, while astronauts venturing outside the International Space Station must wear a jet pack of nitrogen thrusters, they cannot activate the safety measures if they are incapacitated. — TJD, GMA News