After months of tracking down the falling Chinese Space Station Tiangong-1 which finally plunged into the Earth’s atmosphere after burning at re-entry and finally diving northwest to Tahiti Islands in South Pacific Ocean. But there are hundreds of other pieces of debris in the space with few large objects orbiting at the low-earth orbit that scientists track to prevent any collision between any objects. After Tiangong-1, its the Indian Polar Satellite Launch Vehicle (PSLV) which is expected to plunge into the Earth’s atmosphere today (April 3).
Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who keeps a track of all the objects in space said predicted that the 1-ton PSLV rocket body will plunge into the Earth’s atmosphere on April 3, give or take a day. Launched back in 2012, PSLV carried a remote sensing satellite in April after which, the rocket becomes a piece of debris in space. McDowell stated how this space debris is numbered before the fall on Earth if their altitude dip below the orbit of the International Space Station which orbits the planet at 250 miles above the surface.
Once the object is below the 250 miles altitude mark, researchers track into a trajectory that it will follow while hurtling down for which, the velocity depends upon various parameters such as its size to mass ratio and shape and size, etc. An object with small size but larger mass with act as a cannonball while falling whereas, an object with large size but little mass might fall like a leaf.
PSLV is following a circular orbit around the globe, however, not all objects follow the same orbit. For instance, a European rocket named Ariane 5 that was launched in May 2007 follows an elliptical orbit. It has started heading towards Earth after it followed an elliptical orbit which tends to consume its juice everything its reaches near the Earth and then back up. It will soon run out of fuel though.
Another example is the NASA’s Rossi X-ray Timing Explorer (RXTE) satellite that was launched back in 1995 to study the X-ray emissions from neutron stars, white dwarfs, black holes, etc. NASA switched it off in 2012 after which, it becomes one of the candidates in the space junk. It is too expected to re-enter Earth’s atmosphere in mid-April. There are thousands of other objects floating in the space which needs proper disposal before it could turn dangerous.