What are B-2 stealth bombers and bunker-buster bombs?

The US B-2 stealth bomber, often described as the most expensive military aircraft ever built, carries a staggering price tag of approximately $2.1 billion (USD) — or around $3.24 billion (AUD) each.

Manufactured by Northrop Grumman, the B-2 is the only aircraft capable of delivering a weapon powerful enough to strike Iran’s heavily fortified Fordow nuclear facility, which lies deep within a mountain.

With a range of about 6,000 nautical miles (9,600 kilometers), the B-2 can reach virtually any target in the world when supported by aerial refueling. Its stealth capabilities make it difficult to detect, giving it a significant advantage in high-risk missions. The aircraft can carry a wide range of both conventional and nuclear weapons.

Each B-2 bomber carries a two-person crew: a pilot and a mission commander, according to the US Air Force. Only 21 units were produced after the original acquisition plan was scaled back.

Designed to preserve its stealth profile, the B-2’s internal weapons bay can house large payloads — including two GBU-57 Massive Ordnance Penetrators (MOP), known as “bunker-buster bombs.”

The MOP is a 30,000-pound (13.6-tonne), precision-guided munition specifically engineered to destroy deeply buried and hardened targets such as tunnels and underground facilities. Measuring about six meters in length, it is the only non-nuclear weapon believed capable of penetrating the Fordow site.

According to a US Department of Defense fact sheet, the MOP is designed to reach depths of up to 60 meters before detonation. However, air power expert Justin Bronk from the Royal United Services Institute notes that a successful strike on Fordow would require multiple bombs to function flawlessly — penetrating the facility and detonating at the exact depth needed to inflict maximum damage.