Oldest Earth-observing satellite to retire

Posted by Kate Taylor

The US Geological Survey is to decomission Landsat 5 - the longest-operating Earth observing satellite mission ever.

The satellite's had a good run, outlasting its original three-year life by a quarter of a century. The USGS has successfully rescued it from near-death on several occasions, but the recent failure of a gyroscope has been the final nail in its coffin.

Developed by NASA and launched in 1984, Landsat 5 has orbited the planet over 150,000 times while transmitting over 2.5 million images of land surface conditions around the world.  
In its time, Landsat 5 has provided imagery of everything from the Mount Saint Helens eruption and the Chernobyl disaster to global crop production and ice shelf retreat. Nearly 10 million images, each covering over 12,000 square miles, are publicly available online.

"This is the end of an era for a remarkable satellite, and the fact that it flew for almost three decades is a testament to the NASA engineers and the USGS team who launched it and kept it flying well beyond its expected lifetime," says Anne Castle, Department of the Interior Assistant Secretary for Water and Science.

"The Landsat program is the 'gold standard" of satellite observation, providing an invaluable public record of our planet that helps us tackle critical land, water, and environmental issues."

The USGS Flight Operations Team has now begun the process required to safely lower Landsat 5 from its operational orbit, with the first series of maneuvers expected next month.   

Once it's gone, Landsat 7 will continue to provide information - although it too has outlived its five-year design life, and an instrument anomaly reduces the amount of data it collects.

However, Landsat 8 — also called the Landsat Data Continuity Mission — will soon take over, as it's scheduled for launch by NASA in February 2013. The Department of the Interior and NASA are working closely with the government on options for long-term continuity of the Landsat data stream.