NASA Stennis Space Center

NASA has conducted the first of 12 ground-test firings to certify the upgraded Aerojet Rocketdyne RS-25 engine for the Space Launch System rocket.

Rolls-Royce is poised to begin a third phase of ground tests with a pair of dual-podded F130 turbofans for the U.S. Air Force’s B-52J re-engining program.

The rocket-engine-maker mulls next-gen propulsion plans as certification tests of the new-build RS-25 reach the halfway point.

The first all-new RS-25 built in over 15 years incorporates improvements Aerojet introduced into the refurbished former space shuttle RS-25s for SLS flights.

NASA has delayed the planned Feb. 25 full-duration hot fire of the Space Launch System (SLS) core stage due to a faulty valve in the system that supplies liquid oxygen to one of the vehicle’s four Aerojet Rocketdyne RS-25 engines.

NASA did not immediately say why the hot fire was cut off about 67 sec. after ignition.