Landsat 4, 5

Part of the Landsat program

The Landsat 4 and 5 spacecraft were placed into lower orbits than the previous Landsat spacecraft and carried improved instrument suites. Beginning in 1983, Landsat 4 began experiencing numerous spacecraft malfunctions which limited spacecraft functionality. This prompted the early launch of Landsat 5 to guarantee continued coverage. Management of the spacecraft was transferred from NASA to NOAA with Landsat 4.

Spacecraft
Structure of aluminum with graphite struts. Hydrazine propulsion system. Single solar array with 1-axis articulation produces 1430 W (BOL), Two NiCd batteries provide 100 AHr total. Retractable boom (4 m long) with 2 powered joints supports the articulated HGA which downlinks data via TDRSS. Communications system uses S, X, L, and Ku-Bands. 3-axis stabilized, zero momentum with control to 0.01 deg using reaction wheels. Shortly after launch, Landsat 4 lost use of half its solar power. Landsat 5 lost two of its primary communications systems (X-Band downlink and a Ku-Band TDRSS transponder) and backup systems were activated.

Payload
Carried Multi-Spectral Scanner (MSS) and Thematic Mapper (TM) imaging sensors. TM provides 7 bands of coverage and the MSS has 4 bands. The MSS covers 0.5 to 12.6 µ m and provides 80 m resolution with a 185 km swath width. TM covers 0.45 to 12.5 µ m with resolution of 30 meters in the VIS/IR bands and 120 m in the thermal/IR bands.

Country of Origin	United States
Customer/User	NASA, GSFC, NOAA, EOSAT
Manufacturer(s)	GE Astro Space, Fairchild
Size	4.3 m high, 2.2 wide (with HGA and array deployed)
Orbit	705 km circular, polar, sun-synchronous, repeating every 16 days (9:45 am crossing time)
Design Life	5 years
Related Sites	EOSAT Home Page EOSAT Reference Page at Harvard NASA Landsat Page Jennifer Green's Landsat Page

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Landsat 4	1982-072A	7/16/82	WSMC	Delta 3920	LEO	1942
Landsat 5	1984-021A	3/1/84	WSMC	Delta 3920	LEO	1938