The B61-12 nuclear gravity bomb the National Nuclear Security Administration (NNSA) is building will work with the Boeing [BA]-built F-15E Strike Eagle, the Sandia National Laboratories said last week.

“Sandia National Laboratories and the Air Force conducted the full-weapon system demonstration under a full end-to-end test scenario, demonstrating operational crews, representative carriage, release conditions and weapon functionality,” Steven Samuels, a manager with Sandia’s B61-12 system team, said in Thursday’s release. “We were able to test the B61-12 through all operational phases, and we have extremely high confidence the B61-12 is compatible with the F-15E Strike Eagle.”

Eventually, in the U.S., anyway, the B-2 bomber, F-35A Block IV fighter, and later the B-21 Raider will also carry the B61-12, which will be a homogenized version of the four active versions of the B61 bomb: the oldest deployed U.S. nuclear weapon. 

The B-52H no longer carries gravity bombs, instead using the nuclear-armed AGM-86B Air-Launched Cruise Missile. Later, the B-52H will carry the planned Long-Range Standoff cruise missile Raytheon [RTN] is building to replace the current airborne cruise missile.

The NNSA aims to finish the first production unit of the B61-12 bomb in the first quarter of 2022: between one and two years later than hoped, as recently as 2018. Last year, the agency disclosed the B61-12 and W88 Alt-370 submarine-launched ballistic missile warhead would be delayed because commercial capacitors intended for the weapons could not perform to specification during the lengthy deployments planned for both refurbished weapons.