The Landsat program was originally an experimental research project sponsored by the US Dept. of Defense and NASA. Its purpose was to determine the ability of an Earth orbiting spacecraft to provide useful data about current land usage, as well as data that could be used for future land and ocean development. Following the return of data from Landsat 1, it became immediately apparent that such data could be extremely valuable to a wide variety of users, and all Landsat data was made available to the general public.
In 1984, the US government turned over the tasks of satellite operation and data distribution to a commercial entity, EOSAT (Earth Observation Satellite Company). This for-profit company, a joint venture between Hughes and RCA, operates the Landsat 4 and 5 spacecraft and sells the satellite's data. EOSAT is also responsible for the development of Landsat 6 and 7, although the spacecraft are paid for by government funding. Overall Landsat program management is the responsibility of NASA, NOAA, and the US Geological Survey (USGS.)
Landsat-7 is part of the NASA's Mission to Planet Earth.
The principal receiving station is the USGS EROS Data Center in Sioux Falls, South Dakota. Many coutries obtain Landsat data directly from the satellites via dedicated Landsat ground stations in return for an annual usage fee.
fuente: http://msl.jpl.nasa.gov/Programs/landsat.html
