SpaceX's launch of its Dragon cargo spacecraft to the International Space Station (ISS) on Wednesday has been delayed due to a major power shortage that occurred on Monday.
According to
ABC News, an old power-switching unit malfunctioned at the space station Monday and knocked two power channels offline. NASA says no one is in danger and the remaining six power channels are working normally.
The Verge explains what happened: To generate power, the space station uses eight long solar arrays on the outside of the station that convert sunlight into electricity. The electricity is rerouted to all parts of the station through four switches known as Main Bus Switching Units (MBSUs). Right now, one of the MBSU's is acting up and this means two of the eight power channels that provide electricity to the ISS aren’t working either.
In a statement, NASA said: "There are no immediate concerns for the crew or the station. Teams are working on a plan to robotically replace the failed unit and restore full power to the station system. Additional information will be provided as it becomes available."
Canadarm (right) during Space Shuttle mission STS-72.
NASA
CanadArm 2 robotic arm
While the power issue is not affecting the six astronauts aboard the space station, it does affect the station's big robot arm outside. The CanadArm 2 robotic arm is used to capture the Dragon when it arrives at the space outpost and to attach it to the space station.
CanadArm 2 has two power systems - and while only one is used, the other is a backup. Power to the backup system has been affected by the power outage, leaving the robotic arm without a backup. NASA wants all of the robotic arm’s power channels up and running when the capsule arrives in case an issue arises.
NASA spokesperson Dan Huot spoke with
Space.com Monday. Earlier this month, astronauts did work on the CanadArm 2, but the work focused on jumper cables along the arm's length. This time, he explained, the problem was with the space station's equivalent of a circuit-breaker.
