What are the design elements in the B-2 bomber than the video says reduces its radio signature?

Manufacturer: Northrop Grumman Corp.

Power Plant: Four General Electric F118-GE-100 engines

Speed: High subsonic

Range: Intercontinental

Ceiling: 50,000 feet (15,240 meters)

Armament: Conventional or nuclear weapons

Crew: Two pilots

Payload: 40,000 pounds

Explanation:

Designed during the Cold War as the world’s first low-observable or “stealth” strategic bomber, the B-2 Spirit harkens back to the designs of revalutionary engineer Jack Northrop. His “flying wing” design first debuted in 1949 as the YB-49 but was not adopted by the Air Force at the time. The B-2 Spirit is a multi-role bomber capable of delivering both conventional and nuclear munitions. The bomber represents a major milestone in the U.S. bomber modernization program and brings massive firepower to bear anywhere on the globe through previously impenetrable defenses.

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