The B-21 bomber program, the progress of which remains largely secret, has passed yet another preliminary design review, this one ordered by Congress, an Air Force spokesman said. Last week, Air Force vice chief of staff Gen. Stephen Wilson told the House Armed Services Committee that the bomber had recently passed a PDR, but USAF officials had previously stated that the bomber concepts offered by both Boeing/Lockheed Martin and the eventual winner of the bomber contest, Northrop Grumman, had passed PDRs as a prerequisite to bidding. Explaining the discrepancy, the spokesman said, “During the Technology Development phase, the program conducted a weapon system PDR with both offerors prior to source selection.” As part of the Engineering and Manufacturing Development (EMD) phase, “and directed by the Congressional Defense Committees, an additional PDR was conducted to provide additional insight and fidelity into the program design since Technology Development.” The spokesman would only say that the second PDR “was conducted earlier this year” and wouldn’t say when the Critical Design Review—the milestone that locks down the design before manufacturing is set up—will take place. “Due to the critical nature of the technology and capability” of the B-21, “specific details are protected by enhanced security measures,” he said. The program is “moving along on schedule as planned,” he added.
NASA, SpaceX, and United Launch Alliance are all preparing to launch their next-gen rockets from Florida’s Space Coast, two of them before the year is out. One is expected to liberate the U.S. launch enterprise from its reliance on Russian-made RD-180 engines, while all three rockets could eventually carry astronaut crews.