Space junk has rapidly become a major problem for the world’s space agencies. Decades of satellite launches and missions have left the Earth’s orbit filled with pieces of junk such as fuel tanks, lost tools and parts of derelict satellites. It has gotten so bad that space junk has become such a concern for NASA and the ESA, and they are looking at several ways to deal with it. One proposed idea from Astrium UK is to develop a system to harpoon rogue or redundant satellites and pull them out of the sky.
The system would see the harpoon fired at any potentially threatening satellite from close range. A propulsion pack tethered to the projectile would then pull the junk downwards, to burn up in the atmosphere.
Speaking to BBC News, designer Dr Jaime Reed, from Astrium UK said, “Space has become a critical part of our infrastructure – from weather forecasting and Earth observation, to GPS and telecommunications.”
Space junk poses a real threat to these vital services if we do nothing about it, and so it’s very important we develop capture technologies to remove some of this material. Studies have shown that taking out just a few large items each year can help us get on top of the problem.
The harpoon system comprises of a barbed spear about 30cm in length, which is mounted on a “chaser satellite” that would edge to within 100m of a junk object. Once the harpoon is hooked through the skin of the rogue satellite, thrusters would fire dragging it back into the atmosphere.
Prof Richard Crowther, of the UK Space Agency’s chief engineer said speaking to BBC News: “If you’ve watched James Bond films over the years, you know that anything with a harpoon, with a laser, with a net in space has the potential to grab another spacecraft and destroy it. So, we need to build reassurance within the space community and demonstrate that the systems being proposed are peaceful in their nature but also peaceful in the intent and the way in which they are going to be used.”
To put into context the danger of space junk, a piece of metal a mere 1cm in size can hit with the impact of a .22 bullet in orbit, while a piece of junk the size of a tennis ball can hit a space shuttle with the devastation of 25 sticks of dynamite. Currently, there are over one million pieces of junk between 1cm and 10cm in size, not to mention 5,200 derelict satellites.