Ground controllers have completed troubleshooting work after last week’s false alarm indicating an ammonia leak. Heat exchangers and thermal control systems on the U.S. side of the International Space Station have been recovered and reintegrated and are operating in excellent shape.
Commander Barry Wilmore was scrubbing cooling loops on a U.S. spacesuit when he heard an abnormally loud fan pump separator in the suit. He alerted spacesuit engineers who are currently discussing the problem on the ground.
Crew members over the weekend noticed a bad odor coming from Europe’s docked Automated Transfer Vehicle and closed its hatch. European controllers then performed waste tank leak checks and didn’t find any leak indications. Flight Engineer Alexander Samokutyaev is set to reenter the vehicle wearing a respirator mask to investigate.
The International Space Station residents were back at work Thursday after an ammonia leak indication sent the crew over to the Russian segment. Flight controllers determined there was no leak and NASA managers allowed the crew to resume normal activities and open the U.S. segment back up.
This week, the orbital residents kicked off several new experiments delivered Monday morning aboard the SpaceX Dragon commercial cargo craft. Italian astronaut Samantha Cristoforetti worked in Japan’s Kibo lab module feeding fruit flies for an experiment that will observe how long-term microgravity affects the immune system. NASA astronaut Terry Virts set up bacteria kits inside the Destiny lab’s Microgravity Science Glovebox for an experiment that explores the risk of infectious disease in space.
The crew opened the hatch to the U.S. segment and returned inside at 2:05 p.m. Central time. Wearing protective masks, Virts and Cristoforetti sampled the cabin atmosphere and reported no indications of any ammonia.
The International Space Station mission management team, including all of the station Partners, met this afternoon and directed the station’s residents to return to the U.S. segment of the complex before the end of the day, systems permitting. The decision was made hours after the crew members were isolated in the Russian segment following an alarm that could have been indicative of an ammonia leak. The crew is in good condition, was never in any danger and no ammonia leak has been detected on the orbital laboratory. They were informed of the forward plan during their afternoon daily planning conference with flight controllers in Houston, Moscow and the other Partner flight control centers.
Around 3 a.m. Central time today, Station commander Barry Wilmore and Flight Engineer Terry Virts of NASA and Flight Engineer Samantha Cristoforetti of the European Space Agency were directed to don protective masks and move into the Russian segment, closing hatches behind them to the U.S. segment due to the annunciation of an alarm that is part of the environmental systems software on the station designed to monitor the cabin’s atmosphere. At the same time, the station’s protection software shut down one of two redundant cooling loops (Thermal Control System Loop B).
Data received from a variety of system sources on board have been studied by flight controllers throughout the day and indicate no leakage of ammonia on the station. The alarms this morning that initiated the movement of the crew out of the U.S. segment are suspected to have been caused by a transient error message in one of the station’s computer relay systems, called a multiplexer-demultiplexer. A subsequent action to turn that relay box off and back on cleared the error message and the relay box is reported by flight controllers to be in good operating condition.
As a result, the crew will re-enter the station’s U.S. segment today wearing the same protective masks they donned earlier today and will conduct measurements of the atmosphere to make sure there are no traces of ammonia present. Assuming there is no indication of ammonia, the crew will doff their masks and will remain in the U.S. segment for nominal operations.
Meanwhile, flight controllers are continuing to analyze data in an effort to determine what triggered the alarm that set today’s actions in motion. Work to reactivate cooling loop B on the station will continue throughout the night and into the day Thursday. The crew members are expected to resume a normal complement of research activities on Thursday as well.
The six-member Expedition 42 crew is safe in the Russian segment of the International Space Station after an alarm went off in the U.S. segment of the orbital laboratory Wednesday morning.
Flight controllers are seeing no direct evidence of an ammonia leak and are exploring the likelihood a faulty sensor or computer relay set off the alarm.
NASA’s International Space Station Program Manager Mike Suffredini sat down with Public Affairs Officer Dan Huot to discuss today’s events. Suffredini described the crew’s response and how this morning’s situation unfolded. Watch the interview above.
The Expedition 42 crew members are safe and in good shape inside the Russian segment of the International Space Station following an alarm in the U.S. segment at about 4 a.m. EST.
The crew received an update from spacecraft communicator James Kelly that it’s starting to look like a false indication, either a faulty sensor or computer relay. Flight controllers are continuing to analyze the situation but for now, there is still no direct evidence that ammonia was leaked into the station atmosphere.
The Expedition 42 crew members are safe and in good shape inside the Russian segment of the International Space Station following an alarm in the U.S. segment at about 4 a.m. EST.
Flight controllers in Mission Control at NASA’s Johnson Space Center in Houston saw an increase in pressure in the station’s water loop for thermal control system B then later saw a cabin pressure increase that could be indicative of an ammonia leak in the worst case scenario. Acting conservatively to protect for the worst case scenario, the crew was directed to isolate themselves in the Russian segment while the teams are evaluating the situation. Non-essential equipment in the U.S. segment of the station was also powered down per the procedures.
In an exchange at 7:02 a.m. with Expedition 42 Commander Barry Wilmore of NASA, spacecraft communicator James Kelly said flight controllers were analyzing their data but said it is not yet known if the alarm was actually triggered by a leak or whether the situation was caused by a faulty sensor or by a problem in a computer relay box that sends data and commands to various systems on the station.
NASA TV will provide a live update at 7:45 a.m. ET at https://www.nasa.gov/nasatv
The hatches to Dragon were opened for business Tuesday morning at 3:23 a.m. EST and the crew began unpacking critical gear that will support 256 science experiments. The SpaceX commercial cargo craft was attached Monday to the Harmony module at 8:54 a.m.
One experiment that was immediately set up by Flight Engineer Terry Virts was the Micro-5 study. That experiment observes microorganisms as a model for humans so scientists can understand changes in a crew member’s immune system and the risk of infectious disease in space.
The SpaceX Dragon cargo spacecraft was berthed to the Harmony module of the International Space Station at 8:54 a.m. EST. The hatch between the newly arrived spacecraft and the Harmony module of the space station is scheduled to be opened Tuesday, but could occur earlier. The capsule is scheduled to spend four weeks attached to the station.
For an overview of newly delivered science investigations aboard Dragon, visit: https://www.nasa.gov/spacex
While the International Space Station was traveling over the Mediterranean Sea, Expedition 42 Commander Barry “Butch” Wilmore of NASA, with the assistance of Flight Engineer Samantha Cristoforetti of the European Space Agency, successfully captured the SpaceX Dragon spacecraft with the station’s robotic arm at 5:54 a.m. EST.
NASA TV coverage of operations to berth Dragon to the space station will begin at 7:45 a.m.