(CNN) -- Warning alarms awakened crew members on the International Space Station after problems were detected in one of its ammonia-fed cooling loops, NASA said Sunday.
The crew is not in danger, but will be working to troubleshoot the problem and keep the station stable, NASA said.
NASA said the cooling loop shut down around 8 p.m. ET Saturday after monitors detected a power spike in the pump that sends ammonia through the loops. The problem forced other systems on the space station to shut down, NASA said.
The alarms came two days after NASA officials warned space debris could pose a risk to the station. Later Thursday, scientists said the debris was no longer a threat.
Six people -- three Americans and three Russians -- are on the International Space Station.
The station's crew members are conducting more than 100 ongoing experiments in biology, physical sciences, technology development, and Earth and space sciences, according to NASA.