Editor's Pick

Britain's Got Talent on TVNZ Ondemand

Britain's Got Talent

Series 8, Episode 18 Final 22 Jul 14 01:48:44

Top Shows

Contact ONE News

NASA satellite breaks up, plunges back to Earth

Published: 3:28PM Saturday September 24, 2011 Source: Reuters/ONE News

  • A NASA photo of the seven-tonne UARS satelite dated September 1991.
    A NASA photo of the seven-tonne UARS satelite dated September 1991.

A six-tonnes NASA science satellite pierced the atmosphere over the Pacific Ocean and fell back to Earth, the US space agency said today, but it was not yet known where the remains landed.

NASA said its decommissioned Upper Atmosphere Research Satellite, which took an unpredictable course as it tumbled through the upper atmosphere, fell to Earth sometime between 3pm and 5pm today.

"The precise re-entry time and location are not yet known with certainty," NASA said of the 20-year-old satellite.

There were reports on Twitter of debris falling over Okotoks, a town south of Calgary in western Canada, most likely satellite remains.

Stretching 10.6 metres long and 4.5 metres in diameter, UARS was among the largest spacecraft to plummet uncontrollably through the atmosphere, although it is a slim cousin to NASA's 75-tonnes Skylab station, which crashed to Earth in 1979.

Russia's last space station, the 135-tonnes Mir, crashed into the Pacific Ocean in 2001, but it was a guided descent.

NASA now plans for the controlled re-entry of large spacecraft, but it did not when UARS was designed.

The 5,897 kg satellite was dispatched into orbit by a space shuttle crew in 1991 to study ozone and other chemicals in Earth's atmosphere. It completed its mission in 2005 and had been slowly losing altitude ever since, pulled by the planet's gravity.

Most of the spacecraft burned up during the fiery plunge through the atmosphere, but about 26 individual pieces, weighing a total of about 500 kg could have survived the incineration.

The debris field spans about 500 miles (805 km), but exactly where it is located depends on when UARS descended.

With most of the planet covered in water and vast uninhabited deserts and other land directly beneath the satellite's flight path, the chance that someone would be hit by falling debris was 1-in-3,200, NASA said.
"The risk to public safety is very remote," it said.

The satellite flew over most of the planet, traveling between 57 degrees north and 57 degrees south of the equator.

UARS was one of about 20,000 pieces of space debris in orbit around Earth. Something the size of UARS falls back into the atmosphere about once a year.

Advertising