The International Space Station had a close encounter with a piece of space debris this week, when Expedition 18 members were required to take cover in the shelter of the Soyuz landing spacecraft. The Mission Control gave them an all-clear at around 12:45 p.m. on Thursday.
NASA reported that the piece of space debris was around 13 centimeters in diameter, and was in the range of a collision, which is why precautionary measures had to be taken. However, the agency also added that the approach was identified when it was already too late to make an avoidance maneuver. Still, the probability of an impact was still very low.
The crew members on the International Space Station were required to enter the Soyuz TMA-13 capsule and prepare to undock in case of emergency. The piece of debris came from a spent satellite motor, and if it had collided with the station, it would have caused depressurization. The debris came within the International Space Station’s avoidance maneuver requirement box (basically a danger zone).
According to NASA spokesman Josh Byerly, the Soyuz capsule has been used before in similar situations on five different occasions. The piece of space debris doesn’t have to be significantly large to cause damage, and along the years, thousands of pieces of debris of various dimensions have remained floating in space.
This piece in particular was hard to track because its orbit is quite hectic, a NASA official said. Furthermore, there is a possibility that the space station might have another close encounter with it some other time.
A recent collision between an American commercial satellite and a Russian retired satellite has raised a lot of questions on the safety of the rest of the objects orbiting Earth, as well as on space junk, which now reportedly counts over 18,000 pieces of debris.
The European Space Agency said it is reconsidering its options, by funding the Space Situational Awareness Initiative, first introduced last year. One of the mission’s objectives is to survey the objects orbiting the Earth, by detecting, tracking and imaging them.
Nicholas L. Johnson, NASA’s chief scientist for orbital debris, said at one point: “Today’s environment is all right but the environment is going to get worse, therefore I need to start thinking about the future and how I can clean up sometime in the future.”
Johnson also explained that out of the thousands of pieces of debris in space, at least one thousand of them are larger than 10 centimeters, and pose a threat to other orbiting satellites. This threat is likely to last for 10,000 years, it has been estimated.
The International Space Station crew is now back to its normal activities, which include maintenance duties and preparations for the arrival of the shuttle Discovery.
