Landsat 5

Posted on May 14th, 2012 by

The following is a guest blog by Gustavus Geography major Tim LaBombard as part of GEG345 Remote Sensing of Environment.

Landsat 5 is the fifth satellite of the Landsat program and was launched March 1, 1984.  Landsat 5 was originally a three-year mission, but it is currently in its 28th year of orbit.  Landsat 5 has a swath width of 115 miles and travels around the world every 16 days.  Landsat 5 has two main components, which are the Thematic Mapper (TM) and the Multi Spectral Scanner.  The Multi Spectral Scanner was turned off in 1995.

Landsat 5 started to experience major problems in 2006.  On November 26, the solar array drive began exhibiting unusual behavior.  This was troublesome because the solar array drive maintains the proper pointing angel between the solar array and the sun.  The solar array drive was also not able to provide the power needed to charge the batteries.

2009 was a very important year for Landsat 5 because it marked the 25th anniversary of the satellite.  Shortly after this historic event, Landsat 5 ran into some more trouble.  On August 13th Landsat tumbled out of control and on December 18th there were problems with the transmitter, which caused low power.  Finally on November 18, 2011 Landsat 5 was suspended from duty for 90 days, which ended up being 180 days, because of fluctuations in the performance of a critical amplifier.

With all of these problems the Landsat program was left with several options.  They could fix the Thematic Mapper, activate the Multi Spectral Scanner (MSS), and turn off all systems, or lower Landsat 5 from its orbit, 400 miles above the Earth’s surface.  The Landsat program decided to try to activate the Multi Spectral Scanner, but there were doubts because it had not be turned on in 17 years.  The activation was successful and Landsat 5 MSS is up and working again.  It’s life is coming to a close and the Landsat program believes it has several months of life left, in which in will be capturing images of North America.  Overall, Landsat 5 is the true workhorse of Landsat program and has exceeded all expectations.


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