Landsat 4 is the fourth satellite of the Landsat program. It was launched on
July 16th, 1982, with the primary goal of providing a global archive of
satellite photos. Although the Landsat Program is ... managed by NASA, data from
Landsat 4 was collected and distributed by the USGS. Landsat 4 is no longer in
operation, due to technical failure. It finally ceased transmission in 1993,
far beyond its designed life expectancy of five years. The satellite orbit
continues to be maintained by NASA.
Landsat 4 had a maximum transmission bandwidth of 85 Mbit/s, and carried an
updated Multi-Spectral Scanner used on previous Landsats, and a Thematic
Mapper. It had a maximum 30 m resolution. Shortly after launch, the satellite
lost half of its solar power, prompting fears the satellite would fail sooner
than expected. This prompted the early launch of Landsat 5, a satellite
identical in specification to Landsat 4.
[Summary provided by NASA.]