Advanced Propulsion Systems

The Defense Advanced Research Projects Agency has shut down its three-year effort to build the Liberty Lifter, a heavy-lift seaplane that would skim above waves on a cushion of air. According to industry sources, the agency notified performers on July 12 that work had officially ended after internal reviews found no clear path to an affordable prototype within the 2028 schedule.

The Defense Advanced Research Projects Agency has closed the books on its Demonstration Rocket for Agile Cislunar Operations program. Defense officials confirm the termination order went out late Monday. The move ends a five-year push to field a nuclear-thermal upper stage able to sprint between Earth and the Moon. According to industry sources, the agency pulled remaining funds into other space access lines once it judged the return on investment had vanished.