Landsat 4 and Landsat 5 carry both the TM (thematic mapper) and the MSS (multi-spectral scanner) sensors, though routine collection of MSS data was terminated in late 1992. The satellites orbit at an altitude of 705 km and provide a 16-day, 233-orbit cycle with a swath overlap that varies from 7 percent at the Equator to nearly 84 percent at 81 degrees north or south latitude. Landsat data is widely used in many fields including geology, agriculture, resource management, climate analysis etc. The Landsat program is jointly managed by the National Aeronautics and Space Administration (NASA) and the US Geological Survey (USGS). The NERC Earth Observation Data Centre (NEODC) now also holds the data. The cost of retrieving data from these satellites is now prohibitive and they are now obsolete; in 1993 Landsat 6 failed to achieve orbit but the launch of Landsat 7 in 1999 provided open source data at less than commercial prices. See Landsat 7 article.

Note: Gaining access to the Landsat 4/5 TM data will also automatically give you access to the Landsat 7 etm data also held at the NEODC