It is kind of heart breaking to know that we have managed to not only spread litter across our planet Earth but also, the endless space surrounding it. It’s high time we understand that our planet no longer looks like a blue/green globe from a faraway view, but like a candy ball attacked by ants. So how did we manage to do this? And why is it disastrously dangerous? Space debris or ‘space junk’ is comprised of tiny metal shards or parts of decade old satellites, remnants of exploded or discarded rocket parts, old satellites collision leftovers, cancelled experiment equipment etc. According to NASA, this space debris orbiting the earth has reached a tipping point. They can collide and break up, resulting in collisions and trigger a sort of chain reaction. It is reported that around 370,000 such pieces are moving around at a speed of 22,000 mph.
But it’s outside Earth, so what is the big deal? Space seems to be remote concept to us, but is it really that far? Technically, it should be just around two to three hours’ drive straight up. The junk that is orbiting often disturbs the path or can collide with the satellites which are involved in various applications such military, communication, navigation, weather, research, etc. This can also be potential risk to astronauts, space stations and human space crafts too. This debris can grow with time and also collisions could induce a chain reaction resulting in formation of more debris and this is called the Kessler effect. Very small particles travelling at very high speeds that are not tracked from ground could cause a whole chain reaction.
This level of litter wasn’t achieved in a day of course, but from 1950, the time we started exploring the world beyond our atmosphere. The risks of unused satellites and discarded rocket components with fuel inside were never considered until recently. These left over fuel filled components pose a risk of explosion if the temperature increases which in turn results in thousands of metal shards orbiting and colliding. The 2013 blockbuster movie ‘Gravity’ touched on issues surrounding space junk.
In 2007, China experimented by destroying one of its weather satellites in high altitude orbit and this one incident resulted about 3,000 pieces of debris. In 2009, a deactivated Russian communication satellite and an active US communications satellite collided over Siberia. The aftermath of this was almost nothing on the ground, while the impact itself created around 2100 pieces. Many of these now pass frequently very close to the orbiting satellites. The Russian space station MIR launched in 1986 has reported to be hit by objects large enough to penetrate the crew cabin. In 2014, the International Space Station had to change position around three times to prevent getting hit by shards of debris. In 2015, an object called WT1190F, also called WTF, entered the Earth’s atmosphere. It was predicted to crash in the Indian Ocean, just off the Sri Lankan coast. Fortunately, the debris burnt up on entry of the atmosphere.
WTF1190F after its entry in atmosphere
So, can we take this trash out, or have we lost control? Where will the future generations put their satellites? We have a need to think up new solutions for this immediately, since we weren’t thinking when we were decorating the night sky with junk. “Space is a finite resource — just like the atmosphere, and the water, and the Earth, we need to be careful how we use it” says William Schonberg, an aerospace engineer who designs spacecraft to minimize damage from orbital debris. Now, rockets are required to drain fuel and pressure after their use and retired satellites have to be moved to lower altitudes so they can fall back to earth quickly. Several ideas such as ‘Catcher’s Mitt’ where crafts that would use magnets, nets or harpoons to grab junk to bring them to earth and use the pertaining momentum to move on to other objects.
More awareness and cost friendly measures for the space users would be a boon if we would like to continue using satellites for our day-to-day activities and also for the future generations. It’s high time people realise that one day we may not be able to leave this planet anymore because of this floating debris trapping us in, and how would we visit our cousins settled on Mars, then?