The chart below displays the number of scenes visible to all users on EarthExplorer as of June 30, 2015.
In addition to the current Landsat 8 and Landsat 7 missions that are constantly increasing the data in the USGS archive, the Landsat Global Archive Consolidation (LGAC) effort is returning unique Landsat 1-5 MSS and TM data originally downlinked to International Ground Stations into the USGS archive, making even more data available to all users.
The files on the USGS Landsat Global Archive webpage (http://landsat.usgs.gov/USGSLandsatGlobalArchive.php) provide a view of the data added to the USGS archive per satellite, per year.
This scene is just one of over 118,000 that were downloaded during the month of June 2015.
Landsat 8 Path 39 Row 37
Acquired June 22, 2015
This image shows the Salton Sea, an inland saline lake in southeastern California. It is bordered on the south by the rich agricultural areas of the Imperial Valley.
The Landsat archive became available to all users at no charge in December of 2008. As of June 4, 2015, over 26 million scenes have been downloaded by users worldwide.
This graph shows the top ten Landsat data uses from October 1, 2014 through June 30, 2015.