The International Space Station suffered a small power failure on Friday — one that doesn’t pose any immediate dangers to its astronaut crew. One of the eight power channels used to power the ISS is down. The other seven are working just fine, though.
Here’s what happened: Some equipment short-circuited. That tripped a device designed to switch electrical currents on the orbiting lab. Fortunately, there are failsafes, and anything affected was switched to an alternative line of power. The astronauts aren’t in danger, and all six have been working normally since the incident. But the ISS needs a new spare part to fix the power channel — nothing onboard will work, so the part must be delivered via rocket. The part will be delivered on a SpaceX Falcon 9 sometime early next year, says NASA spokesman Dan Huot. SpaceX has yet to release its upcoming launch schedules.
Once the part is delivered to the station, astronauts will likely have to do a spacewalk to replace the broken part and get the power channel running again. This is a lot of work for a short circuit! When your circuit breaker trips on Earth, it’s easy. You just go down to your dark basement, find the wire that’s causing the trouble, and either repair or replace it with wire from Home Depot. On the space station, you have to make do with whatever spare parts you brought with you or wait for the next batch of supplies. (Resupply missions are usually several months apart.) And finally installing your new part means a 5-hour long spacewalk in a cold vacuum, while wearing a suit that may or may not rip your fingernails off.
Technology breaks — particularly in space — and when it does, backups are essential. Allocating room for spares is going to be a big part of any long-term space mission, especially to places like Mars. Resupply missions to the Red Planet will take up to six months, so astronauts will need to bring a lot of replacement parts along with them — orsomehow make them when they get there.