ISS Crew May Need to Evacuate: Possible Debris Hit

by Nancy Atkinson on March 12, 2009

Soyuz attached to the ISS. Credit: NASA

Soyuz attached to the ISS. Credit: NASA

According to, the three crew members on board the International Space Station are being prepared for the contingency of evacuation into the Soyuz spacecraft attached to the station following a “RED threshold late notice conjunction threat” alert. The object’s closest approach would occur at 11:39 CDT, slightly more than an hour from the time of this posting. The object, cataloged as “25090 PAM-D” is orbital debris, and was initially classed as a low threat of collision with the ISS. However, latest tracking suggests the threat is now greater. As a contingency, NASA’s Expedition 18 Commander Mike Fincke, Russian Flight Engineer Yury Lonchakov, and NASA’s Sandra Magnus may be asked to evacuate into the Russian Soyuz, which would serve as their means of departing from the Station – should it be required.
UPDATE: (10:45 am CDT) Communications with ISS crew from mission control confirms the crew will be going into the Soyuz in case of impact. There is a low probability of impact, but the object is large, and if it does hit, they are talking about only a 10 minute reserve time. Fincke will be closing out the hatches on the US segment.
2nd UPDATE (11:15 am CDT) ISS is closing hatches on all the modules in preparation for evacuation into Soyuz. Crew will stay in the Soyuz from 16:30 to 16:45 GMT, possible debris hit would be at 16:39.
Final update: Debris passed harmlessly. See post-event article.

Several memos acquired by relay the probability level of the impact, with the latest noting “It’s now in the red threshold and if it doesn’t improve between now and TCA (Time of Closest Approach) at 11:39am CDT today they will put the crew in the Soyuz per the rules.”

“The plan that has been coordinated with MCC-M (Moscow) is that if required the crew will enter the Soyuz and be in place by 16:35 staying there until at least 5 minutes post TCA,” added another memo.

“We will not be closing any additional hatches to enable us to immediately run the nominal depress procedures should they be needed.

“If the PC remains red the course of action will be to place the crew in the Soyuz from 5 minutes before TCA until 5 minutes after TCA. This is ~2 hours after crew post sleep activities (crew will be awake). ”

We’ll keep you posted.


Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

Previous post:

Next post: