Nuosiluopu·gelumen B-2 Invisible Strategic Bomber(English: Northrop Grumman B-2 Stealth and Strategy Bomber) nicknamed "Spirit"(English: Spirit) was developed by Northrop and Boeing in conjunction with MIT for the United States Air Force Implementation Strategic Nucleum/Conventional Strike Mission Low detectability flying wing bomber. The B-2 is the only stealth strategic bomber in the world today. The main feature is low detectability, which is commonly known as stealth. It can make it safe to attack through a tight air defense system. The stealth of the B-2 is not limited to the radar detection level, but also includes the reduction of different signals such as infrared, visible light and noise, so that the possibility of detection and locking is minimized. In the absence of refueling in the air, the B-2 can reach 12,000 kilometers in combat and 18,000 kilometers in air refueling. The air time for each mission is generally not less than 10 hours. The U.S. Air Force claims that it has "global arrival.