EarthExplorer : provides access to satellite, aerial photographic, and mapping cartographic data products. http://edcsns17.cr.usgs.gov/EarthExplorer/
GloVis : The U.S. Geological Survey (USGS) Global Visualization Viewer (GloVis) is a browse-based tool for selected satellite and aerial data products. http://glovis.usgs.gov/
Landsat International Ground Stations (IGS) Network : Landsat satellites have collected scenes for locations outside the U.S. that are not archived or distributed by the USGS Earth Resources Observation and Science (EROS) Center. These scenes must be ordered directly from the Ground Stations that acquired the data. Data prices, formats, and/or processing options may vary according to the data provider.
Below, the maps show the locations of ground stations operated by USGS International Cooperators (ICs) for the direct downlink and distribution of Landsat 7 (L7) and/or Landsat 5 (L5) image data. The red circles show the approximate area over which each station has the capability for direct reception of Landsat data. The green circles show the components of the U.S. Geological Survey (USGS) ground station network, while the dashed circles show stations with dual status.
Opening the USGS Landsat Archive to the world!
http://landsat.usgs.gov/products_data_at_no_charge.php.
Newly acquired Landsat 7 ETM+ SLC-off and Landsat 5 TM images with less than 40 percent cloud cover are automatically processed and made available for immediate download. Imagery with greater than 40 percent cloud cover can be processed upon request. Once the requested scenes are processed, an email notification is sent to the customer with instructions for downloading. These scenes will then become accessible to all users. Landsat data can be searched, downloaded, or requested from GloVis or EarthExplorer. High demand for this data may result in slow search performance and processing times, which typically range from 1-3 days for Landsat 7 ETM+ and some Landsat 5 TM data and 3-4 weeks for Landsat 1-5 MSS, Landsat 4 TM and some Landsat 5 TM data.