Orbital Sciences to replace AJ-26 engines

Orbital Sciences has said that one of the Aerojet Rocketdyne built AJ-26 engines was probably to blame for the failure of the Antares rocket last week at Wallops Island. David Thompson, the CEO said that the Russian built engines have a reliability issue, and would be replaced by an unspecified engine.

Preliminary evidence is that one of the engines failed 15 seconds after ignition, despite having passed a hot fire acceptance test. Last May another AJ-26 failed when the oxygen turbopump failed explosively. The evidence is pointing to the same failure point in this engine as well apparently.

Orbital Sciences Corp. plans to re-engine its Antares launch vehicle and use one or two alternate launch vehicles initially to meet its International Space Station resupply commitments to NASA after last week’s launch failure with an Antares powered by two Aerojet Rocketdyne AJ-26 engines.

David Thompson, Orbital chairman and CEO, told analysts Wednesday the surplus Russian-built engines have a "fundamental reliability issue" and probably were responsible for the Oct. 28 mishap, which destroyed an Orbital Cygnus cargo vehicle loaded with 4,883 lb. of consumables, hardware and science equipment for the ISS.

However, he declined to specify which engine will replace the AJ-26, repeating an earlier statement that Antares remains in contention for "a number of new launch contracts" that may ride on the engine choice. Russian news outlets have identified the new RD-193, kerosene-fueled engine as Orbital’s pick, and other possibilities include a single Russian RD-180, a solid-fuel rocket motor proposed by ATK, and even restarting production of the Russian NK-33 that is the basis for the AJ-26.

aviationweek.com...

Not a surprising finding, given the previous test-stand failures. More interesting, to me, at least, is that Cygnus will, apparently, be getting a couple rides to the ISS with another launch provider. From the Aviation Week article Zaphod linked to above:

Thompson said Orbital is in discussions with three launch services providers for one or two flights next year with the upgraded Cygnus that was already in preparation for the company’s next mission to the ISS. While he declined to identify those companies, they apparently are SpaceX, United Launch Alliance (ULA) and Arianespace, based on Thompson’s description of them as two U.S. companies and one in Europe.

Given the rapidity with which Orbital is looking to changed the LV it will use for the next couple Cygnus missions, I'm not sure they'll be able to get a spot on SpaceX's manifest for next year; even if they were, I don't know that it would be a wise move to have all of the US's ISS resupply missions riding uphill on the same LV. ULA means either Atlas V or Delta IV, either of which will be VERY expensive.

Arianespace would mean riding on a Ariane V or Soyuz out of Kourou. Given that ESA's contributions to ISS operations are coming to an end with the end of the ATV program, maybe they're in a position to cut Orbital a deal on launch costs in exchange for counting those costs as their contributions to future ISS operations?

a reply to: Zaphod58

Wait...So Aerojet Rocketdyne (a U.S. company) sells refurbished/rebranded Russian-built engines?

I know Aerojet Rocketdyne also has their own engines that they designed and built, such as the RS-25 used for the Space Shuttle main engines and the J-2 engines used for the Apollo program, so I would think that Rocketdyne would have the capability to design and develop their own version of an engine that fits the niche of the AJ-26/NK-33.

a reply to: Box of Rain

The Russian government can't sell them directly to US companies, so they have to have an American partner on board that does the actual selling. Aerojet Rocketdyne didn't have a motor that could be put into use quick enough that Orbital and the other private companies could use it in time to get their programs up and running, so they bought Russian engines.