Above: map created with LIDAR
Various types of artificial satellites such as low earth orbit, geosynchronous, geostationary and sun-synchronous orbit satellites are launched into space to serve particular needs. In an average, 122 satellites are launched every year as opposed to 77 in the previous decade. As there are many satellites being launched, there are as many space debris floating around the earth. Space debris or interchangeably called space junk, space garbage, space litter, space waste or space trash is the mass of non-functioning and obsolete artificially created objects sent into space, notably into the Earth’s orbit. It comprises of fragments ranging from tiny nuts to non-functional satellites resulting from the disintegration, erosion, and collision.
As per the report by United States Strategic Command, there are more than 170 million smaller than 1 cm debris, about 670,000 debris between the range of 1-10 cm and around 29,000 larger debris are present in the space. Collisions with debris pose a serious threat to the solar panels and telescopes or star trackers causing damage similar to sandblasting. It also proves to be a hazard to the spacecraft.
A hypothesis of runaway chain reaction of collisions known as Kessler syndrome predicts the effects of space debris on useful polar-orbiting bands and the hazards it can cause to live satellites. It also envisions the increase in the cost of protection of spacecraft missions from the debris.
With the increasing realization of dangers of these space trashes, scientists have increasingly been working on solutions to remove them. A European Satellite called RemoveDebris satellite was launched earlier this week by the European Space Agency (ESA) to try out different ways to tackle the growth of the enormous amount of garbage in the space. It will use the simple technology of nets and harpoons updated for the use in the outer space.
The RemoveDebris satellite is carrying with itself a number of different devices designed to help clear the humongous amount of space litter orbiting the Earth. It has reportedly docked with the International Space Station (ISS) and is expected to commence the try-outs in the next few weeks. The harpoons will be fired at the targeted debris and will be reeled back after capturing it.One of the harpoons is around 30 cm long and has been designed to target on the arm around 20cm away before it is reeled back in on a rope. A larger harpoon 1.5 meters-long will also be put to capture targets weighing up to eight tonnes. Other devices which are part of the RemoveDebris satellites includes a net to catch the debris, LIDAR-a light based ranging system, and sail to pull the craft back into earth’s atmosphere where it and the trash would burn up.
Scientists are hopeful about the success of the experiment and hope that it can help solve and decrease the space trash floating in space.