{"id":16998,"date":"2022-08-22T16:02:35","date_gmt":"2022-08-22T14:02:35","guid":{"rendered":"https:\/\/www.sciencefocus.com\/?p=126734"},"modified":"2022-08-22T16:22:28","modified_gmt":"2022-08-22T14:22:28","slug":"bits-of-old-spaceships-will-continue-to-fall-out-of-the-sky-but-thats-the-least-of-our-problems-warn-astronomers","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/rss_feed\/bits-of-old-spaceships-will-continue-to-fall-out-of-the-sky-but-thats-the-least-of-our-problems-warn-astronomers\/","title":{"rendered":"Bits of old spaceships will continue to fall out of the sky, but that\u2019s the least of our problems, warn astronomers"},"content":{"rendered":"

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By Colin Stuart\n \t\t<\/p>

Published: Monday, 22 August 2022 at 12:00 am<\/p>

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A strange, black artefact appeared in a paddock nestled in Australia\u2019s Snowy Mountains back in July. It\u2019s a place used to raging bushfires, so you could mistake it for a tree turned to cinder. Yet it came from outer space. Some reports suggest it is a stray piece of a SpaceX Dragon capsule that broke up in the Earth\u2019s atmosphere upon re-entry. Some of it stands upright after spiking into the Australian soil like a javelin. Clearly you wouldn\u2019t want to have been standing there at the time.<\/p>\n

More recently, a large chunk of spacecraft thought to be part of China\u2019s failed Long March 5B rocket launch crash landed in Borneo.<\/p>\n

This is not the first time pieces of space junk have returned to Earth with a bang, but what are chances of it damaging people or property? According to Prof Don Pollacco<\/a>, director of the University of Warwick\u2019s Centre for Space Domain Awareness, even this event was a rare beast.<\/p>\n

\u201cThe surface of the Earth is mostly water \u2013 the chances of this happening on land is really low,\u201d he says. The chances of anyone being hurt by it? \u201cYou\u2019d have a better chance of winning the lottery,\u201d Pollacco says.<\/p>\n

It has happened, though, albeit at sea. Five Japanese sailors were injured when wreckage from a Soviet spacecraft hit a freighter off the coast of Siberia back in 1969.<\/p>\n

Another hairy moment came in 1977 when a Soviet surveillance satellite crashed into Northern Canada. It carried a nuclear reactor on board and only 0.1 per cent of the hazardous fuel was ever recovered. Some of the radioactive material made it into a lake and the Canadian government eventually received three million Canadian dollars from the Soviets to pay for the clean-up operation.<\/p>\n

Dangerous space junk falls may be rare, but that doesn\u2019t mean space junk isn\u2019t a threat.<\/p>\n

\u201cThe danger isn\u2019t deorbiting and landing on someone,\u201d Pollacco says. \u201cThe danger is in damaging other satellites or stopping us launching into space.\u201d<\/p>\n

The region immediately around us in space is fast turning into a junkyard. There are tens of thousands of pieces larger than 10 centimetres across up there. For objects smaller than one centimetre across, the tally runs into the hundreds of millions.<\/p>\n

Bits of old rocket, parts of defunct satellites and even flecks of paint and frozen fuel. Twelve accidental fragmentation events typically occur in space every year as hardware breaks apart and adds to the growing problem. The tiniest objects can still wreak significant havoc.<\/p>\n

\u201cObjects in Low Earth Orbit are moving at 25,000 miles per hour,\u201d says Pollacco. \u201cEven a pea-sized object packs a lot of energy \u2013 if it hit something it would disable a satellite. It\u2019s something we\u2019re going to have to get used to.\u201d<\/p>\n

That\u2019s because the number of satellites being hurled into space is skyrocketing. Companies like SpaceX and Amazon are launching mega-constellations into Low Earth Orbit to beam down the internet to remote places where traditional underground cables can\u2019t reach.<\/p>\n

One report estimates that we\u2019ll launch 1,700 satellites a year between now and 2030. The rapid expansion of space capabilities comes on the back of the advent of reusable rockets. The cost of getting something into Low Earth Orbit has dropped from around $60,000 per kilogram to just $2,400.<\/p>\n

So, what can we do about it? Bodies like the European Space Agency and NASA are advocating debris removal.<\/p>\n

\u201cThere are a number of companies working on this and running demo missions,\u201d says Pollacco. The plan is to dock with a decommissioned spacecraft and haul it down into Earth\u2019s atmosphere to meet a fiery end.<\/p>\n

Pollacco sees big problems, though.<\/p>\n

\u201cThe reality is someone has to pay for this.\u201d He points to a swarm of Russian satellites in a spacecraft graveyard some 800 kilometres above the surface of the Earth. \u201cThey weren\u2019t decommissioned properly and they\u2019re dangerous \u2013 they even still contain propellant,\u201d he says. \u201cIs Russia going to pay to remove them? No.\u201d<\/p>\n

Even then it\u2019s a sticking plaster approach. Removing the thousands of large, dead satellites does nothing about the hundreds of millions of pea-sized satellite killers.<\/p>\n

\u201cIt\u2019s not practical to deorbit those,\u201d Pollacco says. \u201cIn the end you just have to know where it all is.\u201d<\/p>\n

What\u2019s the worst case scenario?<\/p>\n

\u201cYou create a finer and finer cloud of satellite killing debris that would take decades to deorbit,\u201d Pollacco says. Eventually that could create such an obstacle that it affects our ability to put anything new into space.<\/p>\n

\u201cIf your risk of collision during launch is above a certain amount then you don\u2019t launch \u2013 we won\u2019t be able to get off the Earth,\u201d he says.<\/p>\n

We plan to go back to the Moon later this decade and to Mars in the decades ahead, but we could end up firmly rooted to terra firma.<\/p>\n

It seems that space junk falling on our heads may be the least of our problems.<\/p>\n

Read more about space junk:<\/strong><\/p>\n