A B-21 Raider conducts aerial refueling with a KC-135 Stratotanker. (USAF via SWNS)
By Dean Murray
The first jaw-dropping pictures of the United States' nearly $700 million stealth nuclear bomber being refueled in the air have been revealed.
The B-21 Raider is designed to carry a range of conventional weapons and the "secret" AGM-181 LRSO nuclear cruise missile.
The U.S. Air Force said Tuesday (April 14): "The B-21 Raider program continues to accelerate the delivery of long-range strike capability, with aerial refueling via a KC-135 Stratotanker demonstrating the rapid maturation of the weapon system."
Built by Northrop Grumman, the B-21 is set to become a key part of the U.S. Air Force's future bomber fleet and is the most fuel-efficient bomber ever built.
Officials say it will provide long-range strike capability against heavily defended targets.
Air Force Chief of Staff Gen. Ken Wilsbach said: "The B-21's fuel efficiency is one of the core components of its lethality.
A B-21 Raider conducts aerial refueling with a KC-135 Stratotanker. (USAF via SWNS)
"This long-range strike bomber will reduce the demand on our tanker fleet and free up assets to support the joint force."
The U.S. Air Force said: "The ongoing test and evaluation program at Edwards Air Force Base, California, continues to reduce risk and mature the B-21 weapon system, moving it closer to operational service."
It is believed the B-21 will be able to carry the AGM-181A nuclear cruise missile, which is rumored to have an adjustable nuclear yield between 5-150 kilotons, allowing uses ranging from tactical effect to destroying cities.
A yield of 150 kilotons is 10 times more powerful than the bomb dropped on Hiroshima in August 1945.
The missile is set to replace the Cold War-era AGM-86B and will be carried by both the forthcoming B-21 Raider and upgraded B-52 bombers.