London: Now a tractor beam could prevent the accumulation of space debris—including all the dead satellites, discarded rocket boosters and other junk—in the Earth``s orbit, suggests an expert.
Space-flight engineer John Sinko of Nagoya University, Japan, has put forward his idea based on an experimental type of spacecraft engine called a laser thruster.
Inside these motors, laser pulses fired into a mass of solid propellant cause a jet of material to be released, pushing the craft in the opposite direction.
Sinko observed that the laser did not necessarily have to be on the same craft.
"These on-board motors could also be targeted remotely by lasers for tractor beaming," New Scientist quoted him as saying.
A spacecraft could fire a low-power laser beam at another craft to steer it from a distance.
He has designed a series of laser thrusters that can be activated in this way.
A spacecraft fitted with a laser would fire a low-power beam at a thruster fitted on another craft to attract, repel or steer it in another direction.
Pushing a spacecraft away is a relatively simple matter, but more complex designs using mirrors are needed to use a beam to tug one towards the laser.
Combining those designs could allow full control in any direction, said Sinko.
He wants that spacecraft should be fitted with remotely operated thrusters before launch, so that once they reach the end of their lives it is simple to alter their orbit or even shove them into the atmosphere to burn up - even if they have lost all power.
Tractor beams could be fired from up to 100 kilometres away either from a spacecraft in orbit or a mirror in space redirecting a beam from Earth, says Sinko.
Sinko hopes to test one of his tractor beams on a 10-kilogram satellite within a few years.
The study has been published in the Journal of Propulsion and Power.