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Landsat 5 was a
low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...
satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...
launched on March 1, 1984, to collect imagery of the
surface A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is ...
of
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
. A continuation of the
Landsat Program The Landsat program is the longest-running enterprise for acquisition of satellite imagery of Earth. It is a joint NASA / USGS program. On 23 July 1972, the Earth Resources Technology Satellite was launched. This was eventually renamed to Lan ...
, Landsat 5 was jointly managed by the U.S. Geological Survey (USGS) and the
National Aeronautics and Space Administration The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding ...
(NASA). Data from Landsat 5 was collected and distributed from the USGS's
Center for Earth Resources Observation and Science The Center for Earth Resources Observation and Science (EROS) is a United States Geological Survey data management, systems development, and research field center. It serves as the national archive of remotely sensed images of the Earth's land s ...
(EROS). After 29 years in space, Landsat 5 was officially decommissioned on June 5, 2013. Near the end of its mission, Landsat 5's use was hampered by equipment failures, and it was largely superseded by
Landsat 7 Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat program is managed a ...
and
Landsat 8 Landsat 8 is an American Earth observation satellite launched on 11 February 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. Originally called the Landsat Data Continuity Mission (LDCM), it is a ...
.Historic Landsat 5 Mission Ends
/ref> Mission scientists anticipated the satellite will re-enter Earth's atmosphere and disintegrate around 2034. Recognized by ''
Guinness World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...
'' as the longest-operating Earth-observing satellite mission in history, Landsat 5 orbited the planet more than 150,000 times while transmitting more than 2.5 million images of land surface conditions around the world, greatly outliving its original three-year design life.


Specifications

Landsat 5 had a maximum transmission bandwidth of 85
Mbit/s In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
. It was deployed at an
altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...
of , and it took about 16 days to scan the entire
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
. The satellite was an identical copy of
Landsat 4 Landsat 4 is the fourth satellite of the Landsat program. It was launched on July 16, 1982, with the primary goal of providing a global archive of satellite imagery. Although the Landsat Program is managed by NASA, data from Landsat 4 was coll ...
and was originally intended as a backup. Therefore, Landsat 5 carried the same instruments, including the
Thematic Mapper A Thematic Mapper (TM) is one of the Earth observing sensors introduced in the Landsat program. The first was placed aboard Landsat 4 (decommissioned in 2001), and another was operational aboard Landsat 5 up to 2012. /sup> TM sensors feature seven ...
and 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 Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg Sp ...
on March 1, 1984. Landsat 5 recorded many significant events. It was the first satellite to capture the nuclear accident at Chernobyl in 1986. Landsat 5 also documented
deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...
occurring in tropical regions, and captured the devastating 2004 tsunami in southeast Asia. On November 26, 2005, the back-up solar array drive on Landsat 5 began exhibiting unusual behavior. The solar array drive maintains the proper pointing angle between the
solar array A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and ...
and the
Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
. The rotation of the solar array drive became sporadic, and the solar array was not able to provide the power needed to charge the batteries. Maintaining power to the batteries is critical to sustain proper operation of the spacecraft. The primary solar array drive failed under similar circumstances in January 2006. As a result of this situation, imaging operations were suspended. 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 North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
. 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

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 The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program n ...
. 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. On February 10, 2013, NASA announced that the
Guinness World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...
had awarded Landsat 5 the world record for "longest-operating Earth observation satellite" at 28 years, 10 months and counting.


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. When planning began, a date for decommissioning had not yet been set. However, in November 2012, one of Landsat 5's redundant gyroscopes failed, leaving only two operational. If one more failed, the satellite would be left derelict in its valued orbital band. Considering these circumstances, USGS announced on December 21, 2012, that Landsat 5 would be permanently decommissioned as soon as practicable. 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 A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into ...
. 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 array A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and ...
s. The final command shut down Landsat 5's
transmitter In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...
, silencing the mission permanently and effectively terminating the mission 29 years, 3 months and 4 days after its launch. At the time of Landsat 5's decommissioning,
Landsat 7 Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat program is managed a ...
(launched in 1999) and
Landsat 8 Landsat 8 is an American Earth observation satellite launched on 11 February 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. Originally called the Landsat Data Continuity Mission (LDCM), it is a ...
(launched in 2013) remained in orbit. Landsat 8 came online only a few weeks prior to Landsat 5's decommissioning.


See also

*
NASA World Wind NASA WorldWind is an open-source (released under the NOSA license and the Apache 2.0 license) virtual globe. According to the website (https://worldwind.arc.nasa.gov/), "WorldWind is an open source virtual globe API. WorldWind allow ...
(uses Geocover 1990 layer made from Landsat 4 & 5 data)


References


External links


Landsat NASA websiteLandsat USGS website
{{Orbital launches in 1984 Landsat program Spacecraft launched in 1984 Spacecraft launched by Delta rockets