Orbital ATK Completes Antares Hot Fire Test

Orbital ATK conducted a “hot fire” test of its re-engined Antares rocket today at the Mid-Atlantic Regional Spaceport (MARS) at Wallops Island, VA.   The company is preparing to return Antares to flight status after an October 2014 failure.

The version of Antares that failed in 2014 used Russian NK-33 engines, built four decades ago, refurbished by Aerojet Rocketdyne, and redesignated AJ26.   Each Antares launch used one AJ26 engine.   On October 28, 2014, the engine fired, but exploded 15 seconds later.  Orbital ATK and Aerojet Rocketdyne disagreed over the root cause, which was tied to foreign object debris in the engine, but Aerojet Rocketdyne ultimately paid Orbital ATK $50 million.  The details of the investigation are proprietary.

Orbital ATK decided to switch to newer Russian RD-181 engines.  Two of those are needed for each launch.  Today’s test was of an RD-181 engine pair integrated into an Antares rocket.  During a hot fire test, the engines are fired as though a launch was going to take place, but the hold down clamps are not released so the rocket stays on the pad.  A number of modifications were needed to Antares to accommodate the new engines, including a new thrust adapter structure, modified first stage propellant tanks and engine control avionics, and new propellant feedlines.

Antares is launched from Pad OA at MARS, which is located at NASA’s Wallops Flight Facility at Wallops Island, VA on the DELMARVA (Delaware-Maryland-Virginia) peninsula.  MARS is owned by the Commonwealth of Virginia and operated by the Virginia Commercial Space Flight Authority.

Orbital ATK said in a tweet at 6:19 pm ET that the test was complete.

#Antares hot fire test completed at @NASA_Wallops. Team reviewing data now. pic.twitter.com/zwdUxda0Xs

— Orbital ATK (@OrbitalATK) May 31, 2016

In a later press release, Mike Pinkston, General Manager and Vice President, Antares Program, said “early indications are that the upgraded propulsion system, core stage, and launch complex all worked together as planned.”  The test lasted for 30 seconds. The video is on YouTube.

Antares is used for launching Orbital ATK Cygnus cargo spacecraft to the International Space Station (ISS).  The failed launch took place before Orbital Sciences Corporation merged with ATK and was designated Orb-3, the third operational Orbital Sciences launch to ISS.  The missions now are referred to as “OA” for Orbital ATK.

The company has launched two Cygnus spacecraft to ISS using United Launch Alliance (ULA) Atlas V rockets in the meantime.  The first, OA-4, was launched in December 2015 and the second, OA-6, in March 2016.   A firm date for Antares to launch the next in the series, OA-5, has not been finalized, but is currently planned for July 6.  (The numbers are out of sequence because OA-5 on Antares was supposed to launch in the spring.  The fixes to Antares took longer than planned, so OA-6, on Atlas V, was moved up.  The company decided to keep the mission numbers with their rockets, even though the sequence changed.)

The rocket tested today will not be used for the OA-5 mission, but for OA-7 later in the year.   The OA-5 rocket is in the final stages of integration, systems testing and check-out, Pinkston said.

Orbital ATK intends to keep open the option of launching Cygnuses on Atlas V rockets in the future.  It recently won a new set of cargo launches to ISS under the second Commercial Resupply Services (CRS) contract, CRS2.  Orbital ATK Space Systems President Frank Culbertson said in March that the ability to launch on either rocket offers flexibility so both were offered in the contract.

Note: This story was updated with the comments from Pinkston and other information in the press release.