The B-2 Spirit, also known as the stealth bomber, is a long-range strike aircraft built with radar-absorbing materials that allow it to avoid detection by enemy radar. It can fly 6,000 nautical miles without being refueled and can carry up to 20 tons of nuclear and conventional bombs or missiles.
As of 2014, 20 of the original 21 B-2 Spirit stealth bombers are still operational in the U.S. Air Force. One bomber was lost when it crashed on takeoff from Andersen Air Force Base in Guam. Northrop Grumman, the primary B-2 contractor, is responsible for making sure the stealth bombers receive upgrades and remain fully operational.