How a spacecraft stays alive in the (really dangerous) final frontier

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Jan 5, 2018

Space is treacherous enough for humans (too many things can go wrong in microgravity alone), but even though spacecraft may not be made of living cells, it still faces an entire universe of perils out there.

You can’t just load a satellite or rover or telescope onto a rocket and launch it into space, according to Seeker. Anything that is going to be exploring the cosmos for an extended period of time has to be engineered to protect it from all sorts of things it may encounter once it leaves our atmosphere. Spacecraft often get radiation-bombed and have to face extreme heat and cold, dodge random particles that can destroy hypersensitive equipment. Never mind it can collide with one of the 500,000 pieces of space junk—including meteoroids and scrap metal from former missions— floating around.

“The greatest risk to space missions comes from non-trackable debris,” said Nicholas Johnson, NASA chief scientist for orbital debris, which is why the particles that we can’t see are even more of a threat. The debris left behind from comets and even stray flecks of paint from a long-defunct spaceship can mean destruction, especially when they’re hurtling towards your equipment at speeds of up to 17,500 mph.

NASA has at least figured out a way to keep Hubble from getting crushed when it occasionally passes through a meteor shower. The telescope gets rotated so its large solar panels are positioned sideways to pass through the chaos without facing any hazardous rocks head-on, but even that has scientists holding their breath back on the home planet. The ideal way to keep spacecraft from getting scratched and dented is to send it on a course free of cosmic debris, but sometimes, as in Hubble’s case, flying into danger is unavoidable.

Imagine being a piece of metal with hypersensitive guts—and having to contend with this. Credit: NASA

 

Say that telescope or satellite manages not to crash into anything, however microscopic. Background temperatures in space are brutal, like, barely above absolute zero brutal. That doesn’t factor in what happens when something gets caught in the sun’s rays and suddenly gets fried hundreds of degrees depending on how close it is to our resident fireball. ESA ran into this problem with its Rosetta mission when the satellite had to go through a few planetary flybys before it could zoom out to the asteroid belt to stalk a comet. To keep it alive through insanely fluctuating temps, its engineers fitted it with metal slats or thermal “louvres” that can regulate heat by either closing to trap it or opening to radiate it back out into space.  

If it isn’t debris or temperature extremes that get a spacecraft, it could be killer radiation. High-energy charged particles are shooting through the dark all the time. Never mind that these particles are enough of a hazard to astronauts because they can pass through the skin and leave behind some of that energy and warp DNA, which can increase the risk for cancer later on, and acute radiation sickness while still onboard the ship, which is why the ISS is constantly monitored. Particles from the sun or cosmic rays can be just as lethal to spacecraft. They can sabotage an entire mission by corrupting data, burning out computer chips, and creating a current on the surface.

What engineers have been doing to combat radiation is using repeating electronic elements that perform the same function. If one of these dies, the brains of the craft can continue to function. There are also hardened chips designed to shield against intense radiation, but the issue with these is that their processing power can only go up against that of a laptop from about 20 years ago. Computers in 1997 (as anyone who ever waited forever to sign on to AOL can tell you) were not the fastest.

Every preventative measure we have dreamed up so far still isn’t enough to make spacecraft bulletproof when the bullets in question are comet debris and supercharged particles. Equipment is still going to get attacked by the uncontrollable forces it faces after rocketing through our atmosphere, but at least we still have time to get more figured out by the time Earthlings take off for Mars.

(via Seeker)