Spaceflight Insider

Orbital ATK conducts ‘hot fire’ test of upgraded Antares booster


Photo Credit: Orbital ATK

A “hot fire” test of Orbital ATK’s upgraded “enhanced” Antares rocket was conducted today, May 31, in advance of the booster’s return to flight later this summer. The test occurred at 5:30 p.m. EDT (21:30 GMT) at Virginia Space’s Mid-Atlantic Regional Spaceport (MARS) Pad 0A.

The 30-second test comes a year-and-a-half after the Orb-3 launch explosion, some 10 seconds after liftoff. The explosion destroyed the rocket and Cygnus cargo ship that it carried. After the accident much of the launch pad’s equipment needed to be replaced.


Orbital ATK conducts the Antares “hot fire” in advance of the booster’s return to flight later this summer. Photo Credit: Orbital ATK

Since then, the company redesigned and replaced the Antares Aerojet Rocketdyne AJ26 rocket engines—modified Russian NK-33 engines—with the RD-181 (also Russian-built). It was these new engines that were tested today. By all accounts, the test was a complete success.

“Early indications show the upgraded propulsion system, core stage and launch complex all worked together as planned,” Mike Pinkston, Orbital ATK general manager and vice president of the Antares program, said in a press release. “Congratulations to the combined NASA, Orbital ATK and Virginia Space team on a successful test.”

The main purpose of the test was to verify the performance of everything from the engine to the avionics as well as how the launch pad equipment would function in unison with these systems. The test met a number of milestones including full propellant loading sequence, launch countdown and engine ignition, and shutdown commands. Additionally, multiple throttle settings were tested, including full power.

With the test complete, assuming all the data checks out to be good, Orbital ATK can again send the company’s Cygnus cargo ship to the International Space Station using their own launch vehicle.

In order to maintain a supply flow to the station, and meet their contractual obligations to NASA, the company opted to purchase two flights on United Launch Alliance’s (ULA) Atlas V 401 rockets. One flew in December of 2015 (OA-4), the other in March (OA-6) of this year (2016). The OA-6 Cygnus is still attached to the orbiting outpost and is expected to remain berthed there until June 14.

The next step for the company will be to clean the engines of residual propellants and return the stage to the nearby Horizontal Integration Facility (HIF) for reconditioning before being used on the OA-7 Cygnus flight later this year. The booster being used for the OA-5 launch, scheduled for 12:49 p.m. (16:39 GMT) July 6, is undergoing final stages of integration and checkout.

According to Orbital ATK, each new RD-181 engine has undergone hot-fire acceptance testing at the manufacturer’s facility before being shipped to the company. A certification test was completed in spring of 2015 when a single engine was fired seven times for a total of 1,650 seconds—duplicating the Antares flight profile—before being disassembled for inspection.

“The successful stage test, along with the extensive testing of each new RD-181, gives us further confidence in the first stage propulsion and in moving forward to launch,” Pinkston said, “We are now focused on the OA-5 mission and launching the enhanced Cygnus spacecraft to the International Space Station on our upgraded higher-performing Antares rocket.”

Video courtesy of Orbital ATK


Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.

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