AFGSC chief Gen. Timothy Ray told Air Force Magazine, in an interview that will appear in the May issue, that the Air Force has already retired 17 B-1 airframes from the fleet. The remaining B-1s will likely be modernized, some with the ability to carry hypersonic missiles, Ray added.

"My goal would be to bring on at least a squadron's worth of airplanes modified with external pylons on the B-1, to carry the ARRW hypersonic cruise missile," he said.

He said some B-1s "will need significant structural work" to prepare them to air-launch hypersonic missiles. "We can do smart things, and we've got support from Congress to do this. This is a thing that we're working to get ourselves through. We've had a very good dialog," he added.

Modification programs for the B-1s have yet to be added to the fiscal 2021 military budget, Ray said, but it's "a project we're working on. There are several versions that we could contemplate, but we believe the easiest, fastest, and probably most effective in the short term will be to go with the external pylons."

Besides the ARRW, the Air Force is working on other types of hypersonic missiles, such as the Hypersonic Air-breathing weapon Concept. Ray said the B-1 would likely be outfitted with ARRWs, and with external hardpoints, each plane could carry upwards of 31 missiles.

Ray also said the Boeing B-52 Stratofortress bomber would be modernized with new engines, radar, communications, and weapons. There will be external hardpoints on the wings that will allow for hypersonic missiles to be air-launched. He said the combination of the B-1 and B-52 bombers deploying with hypersonic weapons would prepare America for the modern battlefield.