Explorathon '18: The secret (and dangerous) world of space junk
- Published on Thursday, 06 September 2018 06:52
With just under three weeks to go until Explorathon 2018 – Scotland’s European Researchers’ Night (September 28-29), we are highlighting Glasgow’s exciting programme of events and the researchers involved!
Peter McGinty from the University of Strathclyde will host not one, but two Explorathon events on Saturday, September 29! Peter will take us on a discovery of space debris with a special screening of A Beautiful Planet at Cineworld IMAX, Glasgow Science Centre; and a short film at the Planetarium, Glasgow Science Centre looking at the Secret World of Space Junk.
Space debris has a kind of sci-fi kudos attached to it. Space Debris. Space Junk. It almost sounds cool – a hint of mystery and danger. But let’s face it – you can add space to almost anything and it will sound cooler.
The dreary reality is that it’s just another example of humanity’s ability to short-sightedly strive for quick advances/profits/results regardless of the long term consequences.
The oldest piece of space debris is Vanguard 1, which began life as the fourth ever artificial satellite launched into orbit in March 1958. It became debris in 1964 when communication with it was lost. It’s still up there. The noble elder statesperson of space debris: doomed to circle the earth for eons. It almost sounds romantic. Actually it’s about as romantic as an old plastic bottle bobbing around the pacific somewhere.
A few space debris basics:
- In just 60 years humanity has created around 20,000 pieces of trackable debris (anything bigger than around 10cm in diameter)
- Hundreds of thousands more, smaller, untrackable fragments are whizzing around in orbit
- Space debris travels at relative speeds of up to 15km/s
Now orbital missions are expected, if not required, to abide by international agreements aimed at reducing space debris. For example, orbital objects should retain enough fuel so that after their mission they can be brought down to earth in a controlled burn up, or guided into a higher orbit.
This represents a positive first step in dealing with the issue. However, it does nothing to address the ever-increasing catalogue of potentially dangerous shrapnel that already exists. Ever-increasing because every collision between this shrapnel results in a spike in the number of objects and in turn increases the risk of further collisions.
For example, in 2009 the first ever hypervelocity collision occurred between two satellites occurred in Low Earth Orbit (LEO), which is roughly anything within the 100km to 2000km altitude range and is the most densely populated orbit. It hosts a number of vital assets, the most significant of which is the International Space Station (ISS). The immediate increase in debris numbers was massive, but the most dangerous outcomes are not always immediate.
Three years later debris from the collision narrowly missed the ISS. It passed so close that the 6 astronauts boarded escape modules. This is not a one-off. The ISS is at increasing risk from debris. During Tim Peake’s time on board the ISS the viewing window was struck by a tiny piece of debris (something like a fleck of paint) and resulted in a chip being gouged out.
Events like this will become increasingly frequent until we have successfully removed several of the larger debris objects. Even then we will continue to have to clear up the remainder. This is an engineering challenge of the highest and riskiest order.
There is no silver bullet to fix the problem: how do you catch thousands of hypervelocity objects, which are made of different materials, travelling at varying speeds, tumbling in awkward ways? Some are tiny, the size of a football, some are as big as a double decker bust. And those are just the ones we can track! Also, the first attempt needs to be successful, because anything else will result in more space debris!
Space debris threatens our orbital activities. We need access to orbit. We have become dependent on it for our mobile communications, internet, television, and weather and climate monitoring.
If a fleck of paint can take a chunk out of a reinforced window, imagine what a small titanium plate could do!
Stardust training and research network, which is co-ordinated from the Aerospace Centre of Excellence at University of Strathclyde, is investigating the different ways in which the space debris population might be reduced and managed. It’s time to clean up our mess for the good of our future.
Visit the Explorathon website to book free tickets and for more details of other events taking place in Glasgow and across Scotland.
*EXPLORATHON (European Researchers’ Night Scotland) is funded by the European Commission under the Marie Sklowdowska-Curie Actions programme (Grant agreement No. 818500).
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