The ISS has been orbiting the Earth for years as astronauts from multiple countries live aboard the space station and use it as a science platform. Multiple times in the many years the ISS has been in orbit, the orbit has been changed to allow the station to dodge debris and other space junk.
On Sunday, mission control had the thrusters on the ISS fire to move the stations orbit. The change in orbit pushed the ISS about half a mile higher. The reason that the ISS was moved was to get the station out of the way of a potentially hazardous piece of space junk.
The debris that forced the altitude change was a chunk from an old Russian weather satellite. Controllers didn’t know how large the piece of debris was and took no chances with the safety of those on the space station. The satellite that the junk originated from was launched in 1979.
After the ISS altitude was changed, mission controllers determined that the debris posed no hazard. Despite orbiting a half mile higher than it did last week, the altitude change for the ISS will not affect the launch of a new three person crew from Kazakhstan next week. A resupply mission that would have taken off Sunday was delayed.
SOURCE: Florida Today