Orbital ATK [OA] has once again delayed a hot fire test of its re-engined Antares launch vehicle, this time to May 27 at 5 p.m. EDT, a company source tells Defense Daily.
This is the second time Orbital ATK has delayed this hot fire test, a critical step toward Antares returning to flight. The company originally set a March test date based on an earlier set of test requirements, but later revised those test requirements with its NASA customer, who coordinates and approves such test requirements. Orbital ATK then set an early May deadline, which has been pushed back to the end of the month.

Antares is being re-engined with new Russian-developed RD-181 engines after a launch failure in the fall of 2014 severely damaged its launch pad at the Mid-Atlantic Regional Spaceport (MARS), located at NASA Wallops Flight Facility, Va. The vehicle has been out of service since the launch failure. The launch failure was powered by Aerojet Rocketdyne [AJRD]-refurbished engines called AJ-26s. Orbital ATK originally planned to get off those engines, but the launch failure accelerated those plans.
Orbital ATK officials said in December the company planned to have Antares return to flight in the May-June timeframe for a NASA Commercial Resupply Services (CRS) mission to the International Space Station (ISS) called OA-5. Orbital ATK purchased Atlas V launches from United Launch Alliance (ULA) to bridge the gap until Antares could return to flight. In addition to the next Antares CRS mission, Orbital ATK has two more Antares missions at Wallops Island as part of its original CRS contract: One in October and another in 2017.
Orbital ATK and NASA officials did not return requests for comment by press time. ULA is a joint venture of Lockheed Martin [LMT] and Boeing [BA].