The B-2 Spirit is a multi-role bomber capable of delivering both conventional and nuclear munitions. Along with the B-52 and B-1B, the B-2 provides the penetrating flexibility and effectiveness inherent in manned bombers. Its low-observable, or "stealth" characteristics give it a unique ability to penetrate an enemy's most sophisticated defenses and threaten its most valued, and heavily defended, targets. Its capability to penetrate air defenses and threaten effective retaliation was expected provide an effective deterrent and combat force well into the 21st century.
The blending of low-observable technologies with high aerodynamic efficiency and large payload gave the B-2 important advantages over existing bombers. Its low-observability provides freedom of action at high altitudes, thus increasing its range and a better field of view for the aircraft's sensors.
Four General Electric F118-GE-100 non-afterburning turbofan engines (each delivering approximately 19,000 lbs. of thrust) drive the airplane to a maximum speed described as "high subsonic," and to altitudes near 50,000 ft. They also provide an unrefueled range of approximately 6,000 nautical miles. A single aerial refueling extends this to some 10,000 miles and multiple visits to air tankers stretches the range indefinitely.
The B-2's low observability is derived from a combination of reduced infrared, acoustic, electromagnetic, visual and radar signatures. These signatures make it difficult for sophisticated defensive systems to detect, track and engage the B-2. Many aspects of the low-observability process remain classified. However, the B-2's composite materials, special coatings and flying-wing design all contribute to its "stealthiness."
The B-2 has a crew of two pilots, an aircraft commander in the left seat and mission commander in the right, compared to the B-1B's crew of four and the B-52's crew of five.
The B-2 was designed to to deliver gravity nuclear and conventional weapons, including precision-guided standoff weapons. An interim, precision-guided bomb capability called Global Positioning System (GPS) Aided Targeting System/GPS Aided Munition (GATS/GAM) was tested and evaluated. Initially the bomber's principal weapon was the 2,000-pound Joint Direct Attack Munition (JDAM, GBU-31). The basic aircraft continued to undergo multiple modifications, some of which were aimed at correcting deficiencies in the original aircraft design, while others were intended to enhance capability and improve the aircraft's operational effectiveness and suitability. Planned modifications for FY04 and beyond included the addition of an extremely high frequency satellite communication system, upgrades to the DMS, advances in LO materials, Link-16 integration, weapon integration, and periodic software upgrades. Weapons being added included the Enhanced GBU-28 (EGBU-28), the Joint Air-to-Surface Stand-off Missile (JASSM), and the 500-pound JDAM (GBU-38).
The B-2 radar requires an upgrade called the Radar Modernization Program (RMP) to move the radar to a new operating frequency. This upgrade is necessitated to avoid interference with primary authorized users of the current B-2 radar frequency. The RMP as designed will feature an active electronically scanned array and was scheduled to undergo IOT&E in FY07. The B-2 was employed in combat operations during Operation Allied Force (March through May 1999), Operation Enduring Freedom (October 2001), and Operation Iraqi Freedom (March through April 2003).
B-2s, in a conventional role, staging from Whiteman AFB, Missouri, Diego Garcia, and Guam can cover the entire world with just one refueling. Six B-2s could execute an operation similar to the 1986 Libya raid, but launch from the continental US rather than Europe with a much smaller, more lethal, and more survivable force. Using the rotary launcher assembly, all B-2s are capable of employing 16 Mk 84 based JDAMs, 16 JSOWs, or 8 GBU-37/BLU-113s (intended to be replaced by EGBU-28).
Modifications would allow each B-2 to carry 80 500-pound GBU-38 JDAMs. The B-2 can also carry eight of the massive 5,000-pound GBU-37 bunker-buster bombs, and was intended to carry a pair of the 30,000-pound Massive Ordnance Penetrators. Proponents claimed that by 2007 the B-2 could carry 216 [some accounts say as many as 324] of the 250-pound Small Diameter Bombs (SDBs). Each BRU-61/A smart pneumatic carriage holds four SDB weapons, the rack weighs 320 pounds (145 kg) empty, and 1,460 pounds (664 kg) loaded with four 285 pound (130 kg) bombs. In principle, the B-2 has a total of 80 attach points for the 500-lb Mk 82 based GBU-30 JDAM, each of which could accommodate a single BRU-61/A rack, for a total of 320 SDB weapons. In practice, the resulting 117,000 lbs (53,000 kg) weight would exceed the B-2's nominal 40,000 pound (18,000 kilogram) payload by some wide margin. The bomber could of course trade up for somewhat more payload by trading off against fuel and un-refueled range. The widely cited 216 SDB carriage would result in 54 BRU-61/A racks, 27 in each bomb bay, for a total 78,800 pound (35,800 kilogram) payload, roughly double the nominal value.
On 23 February 2008, two air force pilots ejected from their B-2 Stealth Bomber before it crashed on the island of Guam. The crash occurred as the B-2 Stealth bomber was taking off from Andersen Air Force base on Guam, a US territory that lies south of Japan. This is the first crash of a B-2, a $1.2 billion aircraft. At the time the United States had 21 of the bombers (before the crash).