NASA briefly lost contact with International Space Station after power drop

international space station with earth as backdrop
The International Space Station. (Image credit: NASA)

NASA's Mission Control in Houston briefly lost power Tuesday (July 25) and needed a backup to communicate with astronauts on the International Space Station.

The Expedition 69 crew on the International Space Station was never in any danger, NASA officials emphasized Tuesday during a press conference about SpaceX's upcoming Crew-7 astronaut mission to the ISS.

"We were able to talk to the crew through Russian assets about 20 minutes after the failure," Joel Montalbano, NASA's ISS program manager, told reporters. He was likely referring to the systems that mission control in Moscow uses; the ISS has multiple ground stations and satellites to stay in contact as it moves around the world.

Related: SpaceX's Crew-7 astronaut launch delayed to Aug. 17

The outage lasted about for about 90 minutes on Tuesday, between 9 a.m. EDT and 10:30 a.m. EDT (1300 GMT and 1430 GMT, or 8 a.m. to 9:30 a.m. local time at NASA's Johnson Space Center in Houston.)

"We have been doing some upgrades ... to add some reliability to our power systems. We lost the power, the telemetry, the command and the voice to the International Space Station," Montalbano said.

"We knew this work was going on, and in preparation for that we have a backup command and control system that we would use if we have to close the center for weather emergency — especially important during the hurricane season.

"That hardware was ready to go," he continued. "Within about 90 minutes, we were up and running with full command, telemetry and voice to the International Space Station."

NASA officials planned to study the matter in full detail and expected to be "up to a nominal configuration" by the end of Tuesday, Montalbano said.

"Again, no impact to the safety of the crew or the safety of the vehicle, and we'll better understand what happened and then take lessons learned and move forward."

Montalbano said it was the first time that NASA has used these backup systems, and that the mission controllers remained on site through the brief outage as the lights and air conditioning were still operational.

SpaceX's upcoming Crew-7 mission will send four people — NASA astronaut Jasmin Moghbeli, European Space Agency astronaut Andreas Mogensen, Japan Aerospace Exploration Agency astronaut Satoshi Furukawa and Russia's Konstantin Borisov — to the ISS aboard a SpaceX Dragon capsule. 

The quartet are slated to launch atop a Falcon 9 rocket from NASA's Kennedy Space Center at 6:56 a.m. EDT (1056 GMT) on Aug. 17. You can watch it live at, via NASA Television.

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: