The National Nuclear Security Administration (NNSA) on Monday revealed it tested components of the B61-12 gravity bomb it is developing as part of the U.S. nuclear modernization effort.

The two qualification flights took place Aug. 8 at the Tonopah Test Range in Nevada, the NNSA said in a press release published on its website. An Air Force F-15E based at nearby Nellis Air Force Base dropped the non-nuclear test assemblies.

Boeing's F-15 Strike Eagle.  Photo: Boeing
Boeing’s F-15 Strike Eagle was used in recent testing of the B61-12 gravity bomb. Photo: Boeing

It was the second such test of B61-12 flight hardware in 2017. The first took place in March. The qualification program will continue for another three years, the semi-autonomous Energy Department agency said. The NNSA and the Air Force first tested the weapon in 2015 at Tonopah.

The August flight test included hardware designed by the Sandia and Los Alamos national laboratories, which was mated to a tail-kit assembly section designed by the Boeing under contract with the Air Force Nuclear Weapons Center.

The B61-12 program is intended to extend the life of the B61 gravity bomb for 20 years at an estimated cost of $8.1 billion. It will replace four variants of the existing bomb. The first production unit scheduled for delivery by March 2020.