WASHINGTON — Aerojet is in talks with Russian propulsion firms to restart production of the Soviet-era NK-33 rocket engine that the Sacramento, Calif.-based propulsion company is modernizing for use on Orbital Sciences’ Taurus 2 medium-lift rocket.

Aerojet’s vice president of space systems, Julie Van Kleeck, said Aug. 27 that the two companies are weighing the benefits of restarting production of the 1960s engine in Russia, initiating a new line in the United States, or possibly doing both.

“We’re in discussions trying to understand one another’s demand and what the trigger points are and how production might be started in one place or the other,” Van Kleeck told Space News. “It’s a very active situation right now in terms of discussion.”

Orbital Sciences is building the Taurus 2 rocket to launch an unmanned cargo tug called Cygnus that the Dulles, Va.-based company has been working on since early 2008, when it beat a dozen competitors to win a NASA Commercial Orbital Transportation Services (COTS) demonstration contract worth $171 million. In December, Orbital won a Commercial Resupply Services (CRS) contract valued at $1.9 billion to deliver to the international space station a minimum of 20 metric tons of pressurized cargo spread over eight flights between 2010 and 2016. Space Exploration Technologies of Hawthorne, Calif., which has been working on a rival system with NASA’s help since 2006, has a 12-flight cargo-resupply contract worth $1.6 billion.

Slated to make its launch debut in 2010 from NASA’s Wallops Flight Facility on Virginia’s eastern shore, the Taurus 2 will be powered by two modified NK-33 engines. The liquid oxygen and kerosene engines originally designed for Russia’s abandoned Moon program were acquired by Aerojet in the 1990s and more recently redesignated AJ26-62 for use on Taurus 2.

Today, Aerojet has 37 NK-33 engines in the United States, and owns the rights to additional surplus inventory in Russia. Van Kleeck says at this time there are ample NK-33s in the United States and Russia to support Orbital’s planned CRS contract commitment.

“From a U.S. perspective, there are enough engines for CRS to go 10 to 12 years,” she said, adding that a more optimistic view of forecasted U.S. demand would call for starting a new production line within the next three to five years.

The Russians, on the other hand, are looking at more near-term scenarios, she said. Space News was unable to obtain comment from Russian officials by press time, but U.S. industry sources said Russia is interested in restarting NK-33 production to power its Soyuz rockets.

Nikolai Yakushin, the deputy general director of Moscow-based United Engine Corp., wrote Orbital Sciences Chief Executive Officer David W. Thompson in late June to give assurance that Russia will be able to meet Orbital’s demand for the NK-33 engine from existing inventory and a restart of NK-33 production in Russia, according to a U.S. industry source familiar with the letter.

Information posted on Russia’s Samara Space Center Web site says Russia has developed a draft design for a Soyuz 2-3 launch vehicle to include a “gimbaled sustainer engine NK-33-1 with upgraded power capability” for use on the central stage of the rocket.

Van Kleeck said most of Aerojet’s NK-33 modifications are specific to Taurus 2, though Russia may be interested in some modern technologies the company has developed. One U.S. industry source said Russia is eyeing a new gimbal and a number of modern actuators that Aerojet designed for its Americanized NK-33 variants.

“There are a couple of things they are interested in, but we haven’t taken those discussions very far. The specific vehicle mods would not be of interest … it’s more the new hardware that we might be putting in,” Van Kleeck said, adding that any modifications to the original engine would be subject to U.S. licensing requirements for export to Russia.

At this point, Van Kleeck said talks are concentrated on where the new line would be built, though she said Aerojet would prefer a U.S. production line if a sound business case can be made. “The negatives [to restarting a Russian production line] are that you are dealing with purchasing something from another country, and there are just a lot of steps to bringing something like that into this country,” she said, adding that U.S. production would give Aerojet an opportunity to immediately respond to problems that could potentially crop up during manufacturing.

Although the two sides are considering the start of two separate production lines — one U.S., one Russian — Van Kleeck said she is not convinced there is demand for both lines. “There’s a significant investment to put a line like this in place,” she said, adding that regardless, Aerojet is fully prepared to enter production, and has been since the 1990s when the now-defunct Kistler Aerospace designed its K-1 reusable rocket around Aerojet’s modified NK-33.

“We have all the drawings to produce the engines, and have had them translated and are prepared to go into production,” she said. “We need to make sure we have the supply base for various components [we are] buying, and we have some process work to do to replicate things in this country, but we truly don’t see significant risks to do this. It’s not a trivial process to go into production, but we’re fully prepared to do that if it makes economic sense.”

That said, engines produced in Russia likely would cost less than engines produced domestically, she said. In addition, because the NK-33 originates in Russia, it is likely that restarting a production line there could be done more quickly than starting from scratch in the United States, a scenario that could take four or five years.

“We believe there would be a price benefit of being able to purchase the engines from Russia. That might not be true in five years, but that’s the case today,” Van Kleeck said. “Given that uncertainty, we are evaluating both scenarios for U.S. customers, and believe the Russians are doing the same to evaluate their needs.”

At this point, the only clear demand for the NK-33 from Aerojet’s perspective is Orbital and its CRS commitment, which one U.S. industry source said entails two Taurus 2 launches per year. But if the launch rate were to increase, Van Kleeck said there could be a need for new production down the road.

“From a U.S. perspective, in an optimistic sense, you could make the argument that someone needs to start setting up the line three years from now,” she said. “We’re evaluating nominal as well as optimistic cases.”

This fall, Aerojet is planning a long-duration, high-power test firing of the NK-33 in Samara, Russia. Scheduled for late September or early October, the test could raise confidence in the engine. “A successful demonstration will increase the confidence level and allow us to reduce some of the performance margins we’ll be carrying,” Antonio Elias, vice president and general manager of Orbital’s advanced programs group, said Aug. 28. “By performing this ground test, we’ll be able to fly with smaller reserves.”

Van Kleeck said the upcoming test, which Aerojet has been contemplating for more than a year, is not related to discussions about restarting production.

“If, however, these tests result in other future applications, they could become related. If the test is wildly successful, it could lead to future customers and it could drive the need for production sooner,” she said.