Orbital Aborts Test Fire of Antares Rocket

Photo Credit: NASA

Commercial space firm Orbital Sciences Corporation attempted a static test fire of the company’s Antares rocket’s first stage on Wednesday, March 13, but was forced to abort the test. The “hot fire” had been scheduled to take place the day prior, but was postponed. According to a statement appearing on the company’s website, the test was “halted in the final seconds of the countdown by the rocket’s flight computer, which detected an anomalous condition.” 

Orbital is currently looking into the nature of the problem.

During this test, Antares was held in place as the launch vehicle’s engines were ignited. The “hot fire” was conducted at Pad 0A at the Mid-Atlantic Regional Spaceport, or “MARS,” located on Wallops Island, Va.

The test had been slated to last for about 29 seconds. So far, no new date for a full “hot fire” has been announced; experts have deemed it unlikely that the test can be conducted before sometime next week. After a review of the data, Orbital released the following information regarding the anomaly:

After a preliminary overnight review of the data from the hot fire test attempt on February 13, Orbital’s Antares team has identified low pressurization levels of a “nitrogen purge” of the aft engine compartment as the reason the Antares flight computer, acting as designed, aborted the test with about 1.5 seconds left in the countdown. All other aspects of the countdown procedure, from the ground fueling system of the MARS launch complex to the Stage 1 test article, performed nominally. Orbital’s Antares team expects to perform another test before the end of February, with an exact date for the test still to be determined.

The “hot fire” test is conducted to check out the launch pad’s fueling systems and to determine if the Antares’ first stage systems are working as advertised. Technicians and flight controllers use the test to verify these systems in as close to real-world conditions as possible—without actually launching the rocket. The “hot fire” is the last milestone that Orbital must complete prior to launch.

Orbital has scheduled the first flight of Antares to take place sometime next month; it is unclear if that will happen now. When launched, it will carry Orbital’s Cygnus spacecraft into orbit on its inaugural flight.

Cygnus has been developed to deliver cargo to the International Space Station under NASA’s Commercial Orbital Transportation Services (COTS) contract.  However, Cygnus is not the only payload that Antares has been built to hoist into orbit. The new rocket was also designed to launch satellites.

Antares uses two AJ26 rocket engines in its first stage. These are, in actuality, NK-33 engines designed and developed in Russia. Aerojet purchased the rights to produce them and has redubbed them AJ26.

In 2008, Orbital succeeded in winning a $171 million award under NASA’s Commercial Orbital Transportation Services (COTS) contract. Under this agreement the NewSpace firm would demonstrate the viability of Antares and Cygnus. The other firm that competed in COTS was SpaceX, who has already accomplished all of the objectives under the contract and has moved on to the Commercial Resupply Services (CRS) contract. SpaceX currently plans to launch the second mission under that agreement March 1.

* It should be noted that there was a third awardee under COTS—Rocketplane Kistler. However, the NewSpace firm was unable to complete its objectives and was only awarded approximately $32 million. Eventually the company filed under chapter 7 bankruptcy protection and went out of business.