NASA scientists recently reported that they have the necessary technology to move dangerous orbital debris away from spacecrafts and communications satellites with help from ground-based lasers.
Although it may look harmless, space junk is a real threat to stationary man-made objects in low-orbit since it can travel at nearly 17,000 miles per hour. NASA scientists explained that at these speeds a single ounce of space debris can gain the same kinetic energy as a car weighing two tons and traveling at 60 MPH.
And the problems only get deeper as more debris is created after a collision occurs. Moreover, every collision spews high-speed shrapnel around it in a scenario dubbed the Kessler syndrome after the scientist who forecast it in the late 1970s.
In February 2009, a fully functional Iridium satellite clashed with a non-responsive Russian satellite. As a result, the active satellite was irremediably destroyed in the accidental collision. Prof. Kessler, who had predicted the phenomenon in 1978, argued that the orbital debris could become so dense that it could trigger a cascade of collisions that would result in even more debris and the orbit would end up unusable.
NASA scientists said that the low-Earth orbit located at about 560 to 620 miles above ground is already nearing its unusability limit even though no new launches were performed in the area and the dead satellites and rockets were responsibly disposed after the missions were over.
Although a series of solutions to space garbage were brought to scientists’ attention, none of them proved enough efficient and inexpensive. One solution envisioned grabbing large space junk objects such as derelict rocket bodies and dragging them back to Earth. But such mission would be too technically challenging and costly.
NASA scientists recently proposed that we shouldn’t climb up into space to bring down the junk, but we should nudge it with lasers from ground level. In 1996, Project ORION, a NASA and the U.S. Air Force co-sponsored study, proposed powerful lasers to vaporize surface materials on space targets and even slowly nudge them Earthwards. However, the project was abandoned because other nations deemed such lasers threatening weapons.
Currently, NASA researchers claim that their lasers are less powerful and cheaper than those in the 1990s. Also, they cannot be used as military weapons because they cannot damage debris. Instead they can smoothly push it whenever necessary.
Concentrated light can easily move matter around. This property was used by engineers to design solar sails that can propel a spacecraft through space on sunlight. NASA scientists claim that a 5-to-10-kilowatt commercial laser that gets focused on a piece of space junk may just do the trick. They also explained that it should be located in a remote place such as Antarctica.
The research team even conducted a live experiment to prove their hypothesis. They focused a ground-based laser on a 31-inch- wide piece of space junk discarded from the Akari telescope at an altitude of about 434 miles. The laser beam continued to shine on the piece of space trash for about a couple of hours for two straight days. As a result, the piece was eventually moved away from a dangerous orbit.
Image Source: Telegraph.co.uk