The USGS archive holds data collected by the Landsat suite of satellites, beginning with Landsat 1 in 1972. All Landsat scenes in the USGS EROS archive are available for download at no charge. The Search and Download page describes how to find Landsat data.
The USGS Landsat Global Archive provides a graphic view of the acquisition of Landsat data from 1972 to 2013.
Imagery contained only in the USGS EROS archive is included. Landsat data collected at other USGS International Cooperator (IC) ground stations is available directly from the station that collected the data - http://landsat.usgs.gov/about_ground_stations.php.
Currently, both Landsat 8 and Landsat 7 collect data, each following a near-polar, sun-synchronous orbit on the Worldwide Reference System (WRS-2). Each satellite has a 16-day revisit cycle, and they have an 8-day offset. All acquired scenes are downlinked to the USGS Landsat Ground Station and made available for download with 24 hours of acquisition.
The Landsat Acquisition webpage provides daily capture schedules, acquisition calendars, and pending acquisition reports.
The Landsat 8 satellite was launched on February 11, 2013, and carries two instruments: The Operational Land Imager (OLI) sensor and the Thermal Infrared Sensor (TIRS). The satellite is adding over 500 scenes into the USGS archives each day. Details about Landsat 8 can be found on http://landsat.usgs.gov/landsat8.php.
Landsat 7 collects about 300 scenes per day, even though acquisitions since May 31, 2003 are collected and archived as "SLC-off", due to the Scan Line Corrector failure. This failure caused data loss to approximately 22 percent of each scene. Gaps will be visible the majority of the imagery. (see image below). More details about Landsat 7 data products can be found on http://landsat.usgs.gov/using_Landsat_7_data.php. Landsat 7 data acquired from April 1999 to May 2003 provide complete full-scene data.
All currently acquired and most archived Landsat data is processed through Level 1 Product Generation System (LPGS).
A small number of Landsat 4-5 Thematic Mapper (TM) scenes are processed using the National Land Archive Production System (NLAPS). A listing of NLAPS-processed scenes can be found at L4-5TM_NLAPS.xlsx. Details about the differences between LPGS and NLAPS can be found at http://landsat.usgs.gov/products_IP_LPGSvsNLAPS.php.
The Landsat Processing Details webpage provides more information on the standard parameters used and levels of corrections applied to the data.