NASA's Swift telescope set to fall back to Earth this week

NASA's Swift Observatory is expected to fall back to Earth on Wednesday, according to the agency. The space telescope, launched almost 22 years ago, will re-enter the atmosphere after efforts to lift it into a higher orbit did not succeed.

NASA said the observatory is expected to re-enter at about 3:30 AM Eastern Time, give or take 11 hours. The agency expects most of the spacecraft to be destroyed during re-entry, though some components are likely to reach the ground. The reentry zone covers parts of Africa, Australia, Southeast Asia and South America.

Size and weight

The observatory weighs about 3,200 pounds, or roughly 1,450 kilograms. It measures 5.6 metres (18.4 feet) high and 5.4 metres (17.7 feet) wide. Much of the width comes from its deployable solar arrays.

The main risk comes from pieces that survive the descent. Reports describe the spacecraft as roughly the size of a truck, and the surviving debris is the main concern for people on the ground.

The satellite has been in orbit since its launch in 2004, when it began work as a space telescope. Its orbit has been declining, and the attempt to boost it higher was the last effort to extend its life.

It is not yet clear exactly where the debris will land, and the agency has not given a precise location. Readers in India are unlikely to face direct risk, since the reentry zone does not include the country, but the event is a reminder of how old satellites are brought down.