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 the judge, the land that overlooked the base was taken to address security and safety concerns connected with their training and testing. The amount of information the United States government has been willing to provide regarding Area 51 has generally been minimal. The area surrounding the lake is permanently off-limits to both civilian and normal military air traffic. Security clearances are checked regularly; cameras and weaponry are not allowed. Even military pilots training in the NAFR risk disciplinary action if they stray into the exclusionary "box" surrounding Groom's airspace. Surveillance is supplemented using buried motion sensors. Area 51 is a