G Norris, NASA steps up rotating detonation rocket power tests, Aviation Week & Space Technology; 18 September-1 October 2023, p 61

In US, NASA and several universities are applying the rotating detonation concept to rocket propulsion, increasing the specific impulse by 10%, the prime focus being on the durability of the copper alloy GRCop-42 used in construction. Although 4000 lbf of thrust was developed with Loxmethane, 10 000 lbf is the target. Earlier work with gaseous methane and oxygen has been conducted in Japan.