According to NASA, on April 29 an unspecified issue was discovered “with one of the station’s Main Bus Switching Units that distributes power to two of the eight power channels on the station.”
The agency did not say exactly what systems are affected by the fault, but did state that the issue poses no immediate threat to the astronaut currently on board.
According to SpaceFlightNow, the failed hardware is responsible for providing power to several of the station’s systems, including the robotic arm normally used to capture capsule like the Dragon as they approache the ISS.
Fixing the fault will require sending a robot out to replace the failed unit and give the station full power again, and there will be no need for a spacewalk.
The planned Dragon launch is the 17th performed by Elon Musk’s company as part of its contract with NASA. The Dragon will carry three tons of cargoto Earth orbit, including supplies and a host of new experiments for the astronauts to conduct in the coming months.
The International Space Station began taking shape in 1998 with the launch of the first component. ISS is the ninth space station to be crewed in human history, but the only one currently in operation.
The station has been continuously occupied since November 2000, and to date more than 230 people from 18 countries have gone up at the height of 408 km (253 miles).