On Tuesday, a power outage at Nasa’s Johnson Space Center in Houston disrupted communication between Mission Control and the International Space Station (ISS). The incident happened during upgrade work at the center, temporarily severing the astronauts’ ability back on Earth to send commands to the orbiting complex and communicate with the seven astronauts in orbit.
The problem arose because the power outage interrupted the system that typically transmits voice communication and data between the two, reports the Guardian. Fortunately, the backup systems kicked in quickly, and the astronauts were never in danger. The issue is now being investigated.
As the US and Russia operate the station, a joint mission, the two agencies must share information to ensure the astronauts have all the necessary resources. That includes command, control, and telemetry—data about the station’s power levels, temperature, and position.
This communication system has existed for over 20 years, but it’s never failed. On Tuesday, it went down for a little over 90 minutes. It was an unnerving moment for the astronauts living and working aboard the ISS.
That’s because the ISS constantly drifts in its looping trajectory around the planet but usually keeps the same general direction. When it suddenly drifted, the massive pieces of hardware that held the station in place couldn’t keep up, so the ISS started spinning wildly.
At that point, the astronauts could fire thrusters to correct the spin. But the thrusters would require fuel, and that’s a limited resource. “Propellant is like blood,” says an aerospace engineer, and if it ran out, things could get a lot more complicated in a hurry.
Ultimately, the astronauts had to rely on the Russian systems they used for telemetry and commanding. That worked just fine, but it was still an uncomfortable experience. “We’ll better understand what happened and then take lessons learned and move forward,” the Guardian quotes Montalbano as saying.
Nasa does have a separate backup control center located miles from the Johnson Space Center for emergencies. However, since the station still had enough power to keep the lights on, they stayed at the primary location. It’s worth noting that the decades-old station is starting to show its age, and some of its systems are a bit iffy.
The ISS is still flying in a two-gyroscope mode for attitude control because one of its three operating American gyroscopes went down during the power outage. That’s a bit problematic because it means the crew must consume more fuel to orient the station in the future.
The problem with the gyroscopes is just the latest in a long string of issues plaguing the station. It was nearly destroyed when the Russian government decided to blow up a faulty satellite, and the resulting debris field showed no signs of slowing down.