The Chinese space station Tiangong-1 finally crashed to Earth on April 2 over the Pacific Ocean. That is one less space junk circling the space above the Earth. Though Tiangong-1 finally plunged down, it will not be the last to take that plunge. Hundreds of thousands of pieces of junk continue loitering Earth’s low orbit that anyone would want to keep their eye on.

The Indian Polar Satellite Vehicle

One of these space junks is the Indian Polar Satellite Vehicle or PSLV rocket. It delivered into space a remote sensing satellite back in April 2012. The rocket weighs around 907 kilograms or 1 ton, which is far less than the weight of Tianong-1. This space junk is of particular note because The Aerospace Corporation expects it to re-enter Earth’s atmosphere possibly on April 3.

Just like most of the space junk around the planet, PSLV travels around Earth in a circular path. When space debris’ orbits dip blows the International Space Station’s orbit, which flies at 400 kilometers or 250 miles in average altitude, soon they will be tumbling down the Earth. How soon these objects fly down the planet is based on the object’s relative mass.

Taking that into consideration, a large object that has little mass is likely to fall slowly. On the other hand, as small but heavy object is likely to fall hard, like a cannonball. In that case, a space junk that is heavier and higher is expected to come down faster than smaller debris circling at a lower altitude. Another space junk is expected to re-enter Earth’s atmosphere almost at the same time as PSLV.

A Portion of Ariane 5 Rocket Also to Plunge to Earth

Unlike PSLV, however, this space debris does not follow a circular path. On April 3, a part of the European rocket Ariane 5 is also expected to crash to Earth. March 2007 when Ariane 5 launched into space then traveled into an elliptical orbit. In its time above Earth, it dipped close to the planet before swinging several times to a higher altitude to deploy two communications satellites to a geostationary orbit.

Ariane 5 did its job but it left some components in space, including SYLDA, a payload dispenser. This component continued to go around the space where it loses energy whenever it dips close to the planet. It finally reached 475 kilometers or 295 miles in its highest altitude point with 155 kilometers or 96 miles as the closest approach on April 2.