NASA monitors space junk in possible collision path with Atlantis shuttle

Space debris from the wreckage of a satellite has been “tracked" to be on a possible collision path with the Unuted States’ space shuttle Atlantis, according to the US National Aeronautics and Space Administration (NASA). The estimated time of conjunction is around midnight of Tuesday (Manila time). NASA said it is waiting for updated tracking information from the US Department of Defense to determine if the Atlantis crew needs to make maneuvers to get the shuttle out of the debris’ path. The expected time of “conjunction" happens to coincide with a scheduled spacewalk of the crew of the Atlantis and the International Space Station (ISS). According to the NASA Orbital Debris Program Office, the space junk was part of the COSMOS 375, a military satellite the former Soviet Union launched in October 1970 and had an explosive charge in its payload. COSMOS 375 was brought into an orbit close to another Soviet satellite, put on self-destruct and broke up into many pieces. NASA said there are about 500,000 pieces of space debris that are at least the size of a marble in orbit above the Earth. These debris can travel at speeds of up to 17,500 miles per hour and can cause serious damage. Guidelines have long been in place to assure that astronauts are safe from space debris. "These guidelines essentially draw an imaginary box, known as the “pizza box" because of its flat, rectangular shape, around the space vehicle. This box is about a mile deep by 30 miles across by 30 miles long (1.5 x 50 x 50 kilometers), with the vehicle in the center," NASA explained. "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," NASA added. The “probability of collision" is being assessed. NASA said if that chance “greater than 1 in 100,000, a maneuver will be conducted if it will not result in significant impact to mission objectives. If it is greater than 1 in 10,000, a maneuver will be conducted unless it will result in additional risk to the crew." Shuttle and ISS crew have done evasive maneuvers at least 10 times in the past. NASA explained that these movements "are usually small and occur from one to several hours before the time of the conjunction. Debris avoidance maneuvers with the shuttle can be planned and executed in a matter of hours." But the docking of Atlantis with the ISS adds difficulty. "Such maneuvers with the space station require about 30 hours to plan and execute mainly due to the need to use the station’s Russian thrusters, or the propulsion systems on one of the docked Russian or European spacecraft." NASA said. The Atlantis is docked with the ISS to deliver supplies, conduct some experiments and bring down to Earth a defective pump from the ISS. [See: Android phones blast off in last space shuttle flight] Before docking, the Atlantis made a backflip so high-resolution cameras on the ISS can take detailed pictures of the shuttle’s underbelly, which has heat shields meant to protect the shuttle during reentry into the atmosphere before landing. This supply mission to the ISS is the last mission of the space shuttle program after 30 years. "Until a commercial crew vehicle is ready, Russian Soyuz capsules will take astronauts to and from the station," NASA said Monday via Twitter. Atlantis is scheduled to return to Earth on July 20, the 42nd anniversary of the Apollo 11 mission’s moon landing. — RSJ, GMA News