Comment & Analysis
The materials used to develop satellites are designed to be light-weight and effective in delivering their desired activities, such as solar and battery cells, in antennae subsystems and satellite transponders as well as materials for cameras and telescopes. They include titanium and aluminium as well as composites and alloys that are suitable for the space environment. Titanium is recognised as a precious metal, meaning that it is rare and has a high economic value. Each year just under 100 Satellites are launched and these vary in size. In 2017, 90 orbital launches are known to have been attempted, the majority from the USA 32% and Russia 23%, with Europe making 10% of launches.[i]
Modern satellites launched into space today are very different from those launched in the 1970s. They are generally smaller and are unlikely to return to Earth as the Skylab did, making a dramatic re-entry in 1979. The challenge here then becomes two-fold, we lose precious materials used for satellites into space and often these become space debris otherwise known as space junk.
Much like our earthbound environments, such as the oceans and rivers, we have left a lot of human rubbish in space. This space junk is made up from old satellites, lost astronauts’ tools as well as long- forgotten parts of rockets launched over the past 50 years. There are an estimated 500,000 individual pieces of space junk all travelling at speeds up to 17,500mph.[ii] This means that when they collide with each other they create more space junk as pieces shatter into a thousand more. All 500,000 known objects are being tracked by NASA. The challenge we now face is that this junk presents a hazard to space hardware that is in use as well as preventing easy access to our planet’s orbit for new satellites that support our increasing digital lives.
There are five different treaties that cover the peaceful use of the space environment. These include the non-appropriation of outer space by any one country, arms control, the freedom of exploration, liability for damage caused by space objects as well as the safety and rescue of spacecraft and astronauts. The treaties also contain rules governing the prevention of harmful interference with space activities and the environment, the notification and registration of space activities, scientific investigation and the exploitation of natural resources in outer space and the settlement of disputes.[iii]
This means that if a nation launches an object into space it is responsible for any damage that object may cause internationally. However, it is very hard to attribute blame when the damage is caused in space and junk continues to grow as fragments become smaller and smaller. There do not seem to be any regulations governing responsibility for clearing up space waste, but there are a number of different teams looking at how to reduce the debris orbiting Earth. From the Surrey Space Centre a satellite with a net can be used to fish the junk from space pulling it towards Earth to be burnt up on re-entry [iv] and a team from New Mexico are using tiny labels to track space junk and identify its owners.[v]
Our increased interest in space tourism, satellites, and exploration means that the hazards of space junk have to be addressed. Just like other environments we need good international regulation that protects the future of our orbit or else getting off and landing on the planet could become impossible.
[i] http://spaceflight101.com/2017-space-launch-statistics/
[ii] https://www.nasa.gov/mission_pages/station/news/orbital_debris.html
[iii] United Nations Office for Outer Space Affairs. "United Nations Treaties and Principles on Space Law". Retrieved 16 February 2011.
[iv] https://www.bbc.co.uk/news/science-environment-45565815
[v] https://www.insidescience.org/news/scientists-test-tiny-labels-sorting-out-space-debris