Source: Charlene Porter, IIP Digital, U.S. Embassy
Jan. 8, 2013 • Landsat 5 has been orbiting and observing Earth since 1984, long before the computer became a household appliance and a third of the world’s population made everyday visits to a place called the Internet.

The U.S. Geological Survey (USGS) has announced it will begin to decommission the satellite starting sometime in January, ending the longest-operating observational satellite mission in history.

The satellite has provided “unprecedented contributions to the global record of land change,” according to a USGS press release.

“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,” said Anne Castle, assistant secretary for water and science at the Department of the Interior, the Cabinet-level home of USGS.

Landsat 5 was designed for a three-year mission. Dogged engineers have revived the craft several times in the past, allowing it to achieve a 29-year lifetime. The craft has orbited the planet more than 150,000 times as it transmitted more than 2.5 million images of surface conditions worldwide.

“Any major event since 1984 that left a mark on this Earth larger than a football field, whether it was a hurricane, a tsunami, a wildfire, deforestation or an oil spill,” said USGS Director Marcia McNutt.

Data from Landsat 5 has been critical to scientific observation and understanding of changes in the Earth’s surface, which have influenced food production, energy use and disaster relief. The orbiter has logged the impacts of natural hazards, climate change, land use, urbanization and resource demand.

Landsat 7 remains in orbit, and NASA and USGS are set to launch Landsat 8 in February, but McNutt said Landsat 5 will likely retain the title for “outstanding longevity.”

International partners have played a key role in gathering, processing and using Landsat 5 data. More than 20 ground stations operated by as many as 15 nations around the world have collected data and conveyed it to USGS. Ground stations in Australia and the Midwest state of South Dakota have served as primary data-capture facilities for the USGS Landsat Ground Network.

USGS made the Landsat image archive accessible to online users at no cost several years ago. Almost 10 million images have been downloaded in 190 countries, the agency reports.

The USGS Flight Operations Team has begun the process of safely lowering Landsat 5 from its operational orbit. At the same time, USGS, NASA and other U.S. government entities are devising ways to continue the long-term data stream of Earth observation.