It’s not quite the calibre of the Death Star from Star Wars, but Russian space agency Roscosmos is planning to build a laser cannon that will clean up low-Earth orbit, one piece of space junk at a time. Scientists at the Research-and-Production Corporation Precision Systems, which is a subdivision of Roscosmos, aim to attach a giant laser cannon on to a three-metre optical telescope. This laser cannon would have a carefully designed mechanism attached to the telescope, which utilises a series of reflective mirrors, a quartz flash tube and a solid-base generator power supply to create a laser beam powerful enough to evaporate pieces of metal floating around in space.
This telescope is already under development, and its main purpose is to monitor satellites and any potentially dangerous pieces of space junk floating between 160 to 2,000 kilometres (100 to 1,242 miles) above the Earth’s surface. NASA estimates that there are over 500,000 pieces of space junk that are marble-sized or larger in low-Earth orbit, and they can reach speeds of up to 28,164 kilometres (17,500 miles) per hour. These pieces of junk are left over debris from obsolete satellites, space stations or fragments from space collisions. With the International Space Station (ISS) and even more satellites being put into low- Earth Orbit, these pieces of junk can pose a major threat. They could also potentially break through the atmosphere and find their way to the ground, proving to be a potential hazard to us.
Previous events emphasise the dangers of space debris, including the Kosmos-954 incident in January 1978, when the former Soviet reconnaissance satellite reentered the Earth’s atmosphere over Canada; in doing so it broke up into smaller pieces and deposited radioactive material over some 124,000 square kilometres (47,877 square miles) of land. Also, in April 2016, a chip in one of the ISS’ glass panels was thought to be caused by the impact of a tiny piece of space debris – possibly a paint flake or a tiny metal fragment. If it wasn’t for the quadruple-glazed glass, there could have been a serious problem.
For these reasons, the issue of space junk and its disposal has become more important to organisations such as NASA, ESA and Roscosmos. Previous suggestions to remove space junk have included a massive space-net and solar sails to push the debris out of its current orbit. The idea of a ‘giant laser cannon’ is an interesting concept, as it would require a solid-base generator attachment among other instrument concepts to bring this science-fiction idea into reality.
The intensified light would bounce off the mirrors of the telescope until a powerful laser beam is created, which can remove space debris through a process called ‘laser ablation’. This is commonly used to remove layers of material from metals or industrial compounds. However, in the case of this new technology, this laser beam would be able to heat space debris up to temperatures where it would evaporate and be obliterated.