Exactly how much debris is there in outer space?
With the amount of satellites and junk expected to grow ten-fold in the next decade, we are fast reaching a tipping point.
On the 27th of March 2019, Prime Minister Narendra Modi announced that India successfully test-fired an anti-satellite missile by shooting down a live satellite, making it only the fourth country in the world after the United States, Russia and China to acquire the strategic capability to shoot down enemy satellites.
A day later, the US urged all the countries involved to not make a “mess” in space. "We all live in space, let's not make it a mess. Space should be a place where we can conduct business," acting US Defence Secretary Patrick Shanahan said. "If we wreck space, we're not getting it back," NASA chief Jim Bridenstine said in a testimony before the House Appropriations Committee.
Interestingly, the US performed the first anti-satellite tests in 1959, when satellites themselves were rare and new. However, this cautionary note from the US did not name India. Instead, it only raised the concern of space debris.
So, how is space debris created?
A rocket can be described as a metal cylindrical tank that uses a ton of fuel to propel itself into outer space. Whenever a portion of fuel has been spent, the empty tanks are dropped to make the rocket lighter. Some parts crash down to the Earth or burn out in the atmosphere. But most of these useless parts stay up and begin to orbit the planet.
After decades of space travel, the low-orbit zone is now a junkyard of spent boosters, broken satellites, and millions of pieces of shrapnel from missile tests and explosions.
This debris is moving at a speed of about 30,000 km/hr, circling the Earth in a criss-cross orbit, multiple times a day. And these orbital speeds are so fast that being hit by debris the size of a pea (about 1 cm) is like a ray of lightning shot by a plasma gun: on impact, the debris vaporizes, releasing enough energy to punch holes through solid metal.
What’s the problem?
We’ve surrounded our planet with millions of deadly pieces of destruction. And, we also went ahead and put a trillion dollar infrastructure network right in the danger zone, which performs critical duties in a modern world such as global communication, GPS & Navigation, weather forecasting, thermal imaging, laser ranging, and looking out for asteroids, among others.
With the amount of satellites and junk expected to grow ten-fold in the next decade, we are reaching a tipping point. But, the worst thing is not just the debris, but a chain reaction that will surely take place when two satellites collide in just the right way, turning all the non-junk satellites into a thick layer of space debris.
Cleaning up a cosmic mess
There are a lot of ideas of being thrown around, as of now. These include a capture and return mission—netting a piece of junk, or catching debris with a harpoon. Some other sci-fi solutions involve using a giant electro-magnet to push the magnetic components inside the debris towards the Earth’s magnetic field. The tiniest bit of junk could be vaporised entirely by lasers fired through a satellite.
Whatever technology we use, we better start doing something soon before the domino effect kicks in and we’re truly left behind.