Hot firing of Orbital ATK’s re-engined Antares rocket with the RD-181. Photo: NASA

[Via Satellite 06-01-2016] Orbital ATK conducted a full-power “hot fire” test of the upgraded first stage propulsion system of its Antares medium-class rocket using new RD-181 main engines on May 31. Initial indications are that 30 second test, which took place at Virginia Space’s Mid-Atlantic Regional Spaceport (MARS) Pad 0A, was fully successful.

The primary goal of the test was to verify the functionality of the integrated first stage, including new engines, modified Stage 1 core, avionics, thrust vector control and pad fueling systems in an operational environment. Orbital ATK accelerated the first stage engine transition from the Aerojet Rocketdyne-supplied AJ-26 to the RD-181 from NPO Energomash. The engine reached a number of operational milestones during the test, including full propellant loading sequence, launch countdown and engine ignition and shut down commands, as well as multiple throttle settings including full engine power. The test also validated the launch pad’s operation, including propellant tanking and the use of the water deluge system to protect the pad from damage and for noise suppression.

The Antares engineering team will review test data over the next several days to confirm that all test parameters were met. Assuming the success of the test is confirmed, it will clear the way for the resumption of Orbital ATK’s cargo logistics missions to the International Space Station (ISS) from Wallops Island, Va., currently scheduled for July.

Each of the new flight RD-181 engines has undergone hot fire acceptance testing at the manufacturer’s facility prior to being shipped to Orbital ATK. In the spring of 2015, a single engine completed seven test firings, accumulating 1,650 seconds of test time and replicating the Antares flight profile, before being disassembled for inspection.

Orbital ATK will now purge and clean the engines of residual propellants and return the first stage used in this test to the Horizontal Integration Facility for full reconditioning prior to use on the OA-7 mission slated for later this year. The Orbital ATK team will continue to prepare the Antares rocket that will launch the OA-5 mission, which is in the final stages of integration, systems testing and check-out in preparation for launch this summer.