The Landsat program is the longest running satellite program for imaging Earth. It began in 1972 with the launch of Landsat 1 and has continued with subsequent launches of Landsat satellites every few years. Landsat satellites acquire millions of images with spectral bands at resolutions from 15-60 meters to support research in global change, agriculture, geology, forestry and other areas. Landsat 7, launched in 1999, still operates today despite an instrument failure, providing images every 16 days.

1. LANDSAT 1, 2, 3, 4, 5, 6, 7 Satellites and Their Specification
The Landsat celebrating Successful 40 Years.
The Landsat program is the longest running enterprise for acquisition of satellite
imagery of Earth. On July 23, 1972 the Earth Resources Technology Satellite was launched.
This was eventually renamed to Landsat. The most recent, Landsat 7, was launched on
April 15, 1999. The instruments on the Landsat satellites have acquired millions of images.
The images, archived in the United States and at Landsat receiving stations around the
world, are a unique resource for global change research and applications
in agriculture, cartography, geology, forestry, regional planning, surveillance, education
and national security. Landsat 7 data has eight spectral bands with spatial
resolutions ranging from 15 to 60 meters; the temporal resolution is 16 days.

2. General Features
LANDSAT 1 LANDSAT 2 LANDSAT 3 LANDSAT 4 LANDSAT 5 LANDSAT 6 LANDSAT 7
Launch Date July 23, 1972 January 22, March 5, July 16 , 1982 March 1, 1984 October 5, April 15, 1999
1975 1978 1993
Status Expired, Expired, Expired, Decommissioned, TM still lost at Operational despite
January 6, February 5, March 31, June 15, 2001 operational! MSS launch Scan Line Corrector
1978 1982 1983 instrument (SLC) failure May 31,
decommissioned 2003
Sensors RBV, MSS RBV, MSS RBV, MSS TM, MSS TM, MSS ETM ETM+
Altitude 900 km 900 km 900 km 705 km 705 km 705 km
Inclination 99.2° 99.2° 99.2° 98.2° 98.2° 98.2°
Orbit polar, sun- polar, sun- polar, sun- polar, sun- polar, sun- polar, sun-
synchronous synchronous synchronous synchronous synchronous synchronous
Equatorial nominally 9:42 AM mean 9:42 AM nominally 9:45 AM 9:45 AM (± 15 10 AM (± 15 min.)
Crossing Time 9:42 AM local time mean local (± 15 min.) local min.) local time local time
mean local (descending time time (descending (descending (descending node)
time node) (descending node) node)
(descending node)
node)
Period of 103 minutes; 103 minutes; 103 minutes; 99 minutes; ~14.5 99 minutes; ~14.5 99 minutes; ~14.5
Revolution ~14 ~14 ~14 orbits/day orbits/day orbits/day
orbits/day orbits/day orbits/day
Repeat 18 days 18 days 18 days 16 days 16 days 16 days
Coverage