SpaceX was supposed to launch a shipment from Cape Canaveral, Florida, on Wednesday.
NASA confirmed Tuesday the agency had requested SpaceX move the launch to Friday due to the issue with the Main Bus Switching Units, which distribute power to two of eight power channels on the ISS. "It effectively loses one quarter of the power to the space station", said Bill Gerstenmaier, NASA associate administrator for human exploration and operations, during an April 30 presentation to a joint meeting of the Space Studies Board and Aeronautics and Space Engineering Board here. But because of the hobbled solar-power grid, the SpaceX launch is off until at least Friday. And according to CBS, those channels powered the robot arm that attaches to SpaceX's capsule and helps berth it with the station. The failed unit means two of those eight channels have no power. And while it can operate with one source of power, NASA rules require a backup, CBS reported.
Flight controllers will use the robot arm to replace the faulty unit with a spare later this week, saving the astronauts from going out on a spacewalk.
There's no rush for this delivery.
Unfortunately, the space station's power distribution system is acting up, and it will take some time to complete the repairs.
Thankfully, no one is in immediate danger, but the partial power loss means that SpaceX is going to need to wait before launching its CRS-17 Dragon resupply mission carrying almost 5,500 pounds of experiments and supplies.
Six weeks after a successful test flight without a crew to the space station, the Dragon was engulfed in flames during a ground test. SpaceX was in the process of firing the capsule's thrusters on a test stand.
SpaceX and NASA have offered few details.