Although NASA officials decided that the upcoming Extra Vehicular Activity (EVA2) would not be delayed, a Debris Avoidance Maneuver (DAM) may need to be executed once astronauts John Olivas and Christer Fuglesang (both Mission Specialists) replace the station’s ammonia tank during their spacewalk.

Astronaut John "Danny" Olivas, STS-128 mission specialist, participates in the mission's first session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station - Photo Credit: NASA

In March earlier this year, the station’s crew was evacuated to the Soyuz spacecraft as the station was threatened by a orbital debris from the Cosmos – Iridium collision a few weeks earlier.

Astronaut Michael Fincke, Expedition 18 commander, participates in a session of extravehicular activity (EVA) to perform maintenance on the International Space Station - Source: NASA

Update #1: 21:54UT – NASA CAPCOM Rick Davis just informed the International Space Station (ISS) Commander Mike Fincke (who celebrated his 42nd birthday on Saturday) that the station will NOT need to maneuver tonight to avoid the satellite debris. Thus it seems that the crew can continue their prepration for the visitors from STS-119 shuttle which will dock with the station tomorrow at 19:13 UT 22:13 UT.

Soyuz Module Docked at the ISS - Source: NASA

The crew of the International Space Station (ISS) is being evacuated to the Soyuz spacecraft as the station is threatened by a piece of orbital debris, cataloged as “25090 PAM-D”, from the Cosmos – Iridium collision last month. The closest approach will occur at 16:39 UT and the astronauts will be placed in the Soyuz from 5 minutes before until 5 minutes after.

More info is available at Universe Today site. You can also watch the NASA TV broadcast about ISS evacuation.

UPDATE: @16:47 UT – 9 minutes after the time of the closest approach (TCA) and seems that ISS is intact. The odds of collision were quite low (although much higher than the usual when it comes to orbital junk). Nevertheless, NASA plays everything safe.

UPDATE 2: @16:50 UT – The danger is over. The debris the station in a, for the crew not-so-much, comfortable distance. The astronauts are carrying out various tasks to bring the station back “online” after the emergency shutdown.

UPDATE 3: @17:00 UT – All hatches have been re-opened and it is back to the work time for the crew. I bet that was enough adrenaline for today.

UPDATE 4: @17:04 UT – It seems that the culprit was a Payload Assist Module (PAM) – a solid rocker upper stage used to boost satellites to high orbits). That would have been one big fireworks. Bad Astronomer has now more info about the debris. It was actually only a small part of the entire module, weighting about 1kg but at relative speeds of around 10km/s it would still cause a lot of damage had it strike the station.

It is truly exciting to have the technology (Twitter, NASA TV) accessible to anyone to follow these kind of events while they happen, instead of reading about them on CNN hours later.