Image shows ISS crew members (from left) Nicole Stott, Frank De Winne and Robert Thirsk talk to Belgian media during a European Space Agency in-flight event. Credit: NASA TVAs the International Space Station’s six spacefarers continued preparations Friday for the arrival of a new module and a visiting space shuttle, they also were informed that a small piece of space junk might pass close enough to require precautions.
However, flight controllers decided not to put the crew in the Soyuz vehicles at the ISS, declaring that the space debris they have been tracking no longer poses any concern or threat. Mission Control will wake the crew as planned as a precautionary measure while the debris passes.
The crew was notified of the 5-centimeter-long piece of space debris about 10:04 a.m. EST. The U.S. Space Command routinely tracks space debris in orbit around the Earth, and reports to NASA any possible “conjunctions” or close passes to the space station. About 5:15 p.m., Spacecraft Communicator Ricky Arnold radioed the crew that additional tracking passes showed the debris was no longer a threat.
NASA has a set of long-standing guidelines that are used to assess whether the threat of such a close pass is sufficient to warrant evasive action or precautions to ensure the safety of the crew.
These guidelines essentially draw an imaginary box, known as the “pizza box" because of its flat, rectangular shape, around the space station. This box is about half a mile deep by 15 miles across by 15 miles tall (0.75 x 25 x 25 kilometers). When predictions indicate that the debris will pass close enough for concern and the quality of the tracking data is deemed sufficiently accurate, Mission Control centers in Houston and Moscow work together to develop a prudent course of action.
Sometimes these encounters are known well in advance and there is time to move the station slightly, known as a “debris avoidance maneuvre” to keep the debris outside of the box. Other times, the tracking data isn’t precise enough to warrant such a maneuver or the close pass isn’t identified in time to make the maneuver.
The crew was notified of the 5-centimeter-long piece of space debris about 10:04 a.m. EST. The U.S. Space Command routinely tracks space debris in orbit around the Earth, and reports to NASA any possible “conjunctions” or close passes to the space station. About 5:15 p.m., Spacecraft Communicator Ricky Arnold radioed the crew that additional tracking passes showed the debris was no longer a threat.
NASA has a set of long-standing guidelines that are used to assess whether the threat of such a close pass is sufficient to warrant evasive action or precautions to ensure the safety of the crew.
These guidelines essentially draw an imaginary box, known as the “pizza box" because of its flat, rectangular shape, around the space station. This box is about half a mile deep by 15 miles across by 15 miles tall (0.75 x 25 x 25 kilometers). When predictions indicate that the debris will pass close enough for concern and the quality of the tracking data is deemed sufficiently accurate, Mission Control centers in Houston and Moscow work together to develop a prudent course of action.
Sometimes these encounters are known well in advance and there is time to move the station slightly, known as a “debris avoidance maneuvre” to keep the debris outside of the box. Other times, the tracking data isn’t precise enough to warrant such a maneuver or the close pass isn’t identified in time to make the maneuver.
In those cases, the control centers may agree that the best course of action is to move the crew into the Soyuz spacecraft that are used to transport crew members to and from the station so that they could isolate those spaceships from the station by closing hatches, and then leave the station if the debris were to collide with the station and cause a loss of pressure in the life-supporting module. The Soyuz act as lifeboats for crew members in the event of an emergency.
Mission Control also has the option of taking additional precautions, such as closing hatches between some of the station’s modules, if the likelihood of a collision is great enough.
Mission Control also has the option of taking additional precautions, such as closing hatches between some of the station’s modules, if the likelihood of a collision is great enough.
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