Area 51 providers (including Russian providers and the IKONOS) are commercially available. These show the runway markings, base facilities, aircraft, and vehicles. When documents that mention the Nevada Test Site (NTS) and operations at Groom are declassified, mentions of Area 51 and Groom Lake are routinely redacted. One exception is a 1967 memo from CIA director Richard Helms regarding the deployment of three OXCART aircraft from Groom to Kadena Air Base to perform reconnaissance over North Vietnam. Although most mentions of OXCART's home base are redacted in this document, as is a map showing the aircraft's route from there to Okinawa, the
Area 51 aerospace magazine "The Space Review" titled "Astronauts and Area 51: the Skylab Incident". The article was based on a memo written in 1974 to CIA director William Colby by an unknown CIA official. The memo reported that astronauts on board Skylab 4 had, as part of a larger program, inadvertently photographed a location of which the memo said: Although the name of the location was obscured, the context led Day to believe that the subject was Groom Lake. As Day noted: The memo details debate between federal agencies regarding whether the images should be classified, with Department of Defense agencies