Landsat 5 was a low Earth orbit satellite launched on March 1, 1984, to collect imagery of the surface of Earth. A continuation of the Landsat Program, Landsat 5 was jointly managed by the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA). Data from Landsat 5 was collected and distributed from the USGS's Center for Earth Resources Observation and Science (EROS).
After 29 years in space, Landsat 5 was officially decommissioned on June 5, 2013. Mission scientists anticipated the satellite will re-enter Earth's atmosphere and disintegrate around 2034.
Specifications
Landsat 5 had a maximum transmission bandwidth of 85 Mbit/s. It was deployed at an altitude of , and it took about 16 days to scan the entire Earth. The satellite was an identical copy of Landsat 4 and was originally intended as a backup. Therefore, Landsat 5 carried the same instruments, including the 30m resolution Thematic Mapper and 60m Multi-Spectral Scanner. The Multi-Spectral Scanner was powered down in 1995, but reactivated again in 2012.
Mission history
Landsat 5 was launched by NASA from Vandenberg Air Force Base on March 1, 1984. After a month-long investigation in December 2005 and testing in January 2006, new operating procedures were developed that would allow Landsat 5 to continue normal operations.
On December 18, 2009, the transmitter on Landsat 5 experienced technical difficulties. Data downlink was restored on January 7, 2010, after a test successfully managed to retrieve a picture over North America. This test exercised the only remaining Traveling Wave Tube Amplifier (TWTA). The remaining TWTA is in fact the primary TWTA that was in operation when Landsat 5 launched in 1984. After several issues in late 1986 and 1987, the primary TWTA was turned off and the secondary redundant TWTA was used. The USGS Flight Operations Team applied lessons learned while operating the redundant TWTA to the primary TWTA for its first successful transmission in over 22 years.
On November 18, 2011, image acquisitions were suspended for a period of 90 days, due to fluctuations in the performance of a critical amplifier in the satellite's transmission system. USGS indicated the satellite was nearing the end of its life, after more than 27 years in space.
Longevity
thumb|Delta rocket launching Landsat 5 out of Vandenberg Air Force Base
Landsat 5 significantly exceeded its designed life expectancy, lasting several decades beyond its original three-year mission. Contributing to Landsat 5's longevity was the presence of extra fuel for possible future retrieval by the Space Shuttle. If the need arose, Landsat 5 could use the extra fuel to move into a lower orbit. Instead, the extra fuel was used to maintain its existing orbit as long as practicable.
End of mission
In mid-2012, with the satellite suffering multiple mechanical failures, the USGS Landsat team began planning a complex series of steps to ensure that the satellite's decommissioning would meet the requirements set under international agreements.
Landsat 5 transmitted its last image on January 6, 2013. Nine days later, USGS Mission Operations began the process of maneuvering the satellite from its operational orbit into a lower disposal orbit. On June 5, 2013, with Landsat 5's fuel reserve completely depleted, the USGS Flight Operations Team issued commands to shut off all moving mechanisms and hobble the spacecraft's ability to generate and store power from its solar arrays. The final command shut down Landsat 5's transmitter, silencing the mission permanently and effectively terminating the mission 29 years, 3 months and 4 days after its launch.