The biggest opportunity in nearly two decades appears tantalizingly close for a U.S. liquid-fuel propulsion industry that for a generation has seen nothing but contraction.
Amid Russian threats to limit access to the RD-180 engine that powers one of the U.S. Defense Department’s two main workhorse rockets,’s Atlas 5, Congress is pushing to fund work on a domestically built alternative starting next year. recently said it has awarded contracts to multiple U.S. companies to develop new engine concepts, with an eye toward a first launch in 2019.
Although ULA declined to identify the contract recipients,seems all but certain to be among them. Created one year ago via Aerojet’s acquisition of rival Pratt & Whitney Rocketdyne, the company is the last player standing following the post-Cold War consolidation of the traditional liquid-fuel propulsion industry.
Aerojet Rocketdyne has a fairly well developed concept in mind: the liquid-oxygen (LOX)-kerosene-fueled AR-1, which will generate 500,000 pounds of thrust, about half that of the Russian-built RD-180. Julie Van Kleeck says the engine concept was developed with some government study funding and internal investment, which she declined to quantify.
Although Aerojet Rocketdyne is an obvious front-runner, Van Kleeck said there are other companies that could credibly compete for a new engine development contract should it ultimately materialize — still a big if. Among them is Space Exploration Technologies Corp., which builds the kerosene-fueled engines for its Falcon 9 rocket in house.
Van Kleeck spoke recently with SpaceNews Editor Warren Ferster.
How soon and at what cost could Aerojet Rocketdyne complete development of the AR-1?
We believe we can qualify an engine within four years and be ready to fly by 2019. Our latest assessments are between $800 million and $900 million to do that. It depends on customer requirements and things like that, but that’s a pretty good ballpark.
Why do an engine with only half the thrust of the RD-180?
We’ve done a lot of studies on this over the past several years looking at today’s launch market as well as the future launch market. And that’s how we arrived at the 500,000-pound-thrust engine — we felt that would service the most markets. We have a modular approach, so you use 500,000 pounds for a smaller launch vehicle, you’d use two in a twin set for 1 million pounds, and you can scale this up to larger missions such as the advanced booster that NASA might have in the future. We believe the 500,000-pound-thrust engine is the most cost-effective way to solve those problems.
Could you scale up to 1 million pounds with this engine?
If the requirement was for a million pounds thrust we have a design concept that can do that. The cost is a little bit higher and the time — it’s a little more challenging to test a million-pound-thrust engine as opposed to a 500,000-pound-thrust engine, but the technologies would be similar.
What is the heritage of the AR-1?
We started with an Aerojet design and then with the Rocketdyne acquisition we’ve incorporated what we believe are the best technologies — both in materials and advanced processes — from both companies.
Why do you suppose the government is focused on a LOX-hydrocarbon fuel, either kerosene or methane, as opposed to LOX-hydrogen?
LOX-hydrogen definitely has its place in the market, particularly in the area of upper stages and many of the human-rated systems that we’ve put together because of the legacy. With expendable launch vehicles, and particularly as we have focused on affordability, kerosene is a simpler propellant to handle. You also end up with a smaller launch vehicle because it’s a higher-density fuel. All those things translate to a lower cost.
Gen. William Shelton, commander of Air Force Space Command, recently suggested methane is the way to go. What do you think?
Methane’s been evaluated for at least 50 years as far as I know and typically, for boosters, it doesn’t trade any better than kerosene.
Are you capable of doing a LOX-methane engine?
We have a lot of methane capability and products in the technology development stage, but our customers have never desired that technology. Our trade studies indicate that it has an advantage of slightly higher performance, but it’s less dense. That means that you need larger tanks, which typically is a little more expensive — the larger the launch vehicle, the more expensive. If that’s the direction that a prime contractor or our government wants to go, we can certainly supply methane engines. But it’s just not compelling.
Why do you suppose the government seems so interested in methane?
It’s difficult for me to see why.
Should the government pursue a new engine, will it need a new rocket to go with it?
There are always interfaces that have to be considered and adapted to and there’s always some form of certification with any change. With the type of architecture we’re talking about with the 500,000-pound-thrust AR-1, we believe that’s fairly minimal for it to be adapted to the Atlas vehicle. We understand that interface very well, as well as the launch vehicle.
How closely is the AR-1 based on the NK-33/AJ-26 engine that was built in Russia and refurbished by Aerojet for use on Orbital Sciences Corp.’s Antares rocket?
The AR-1 is an American design, not a Russian design. Our people have gained experience with the oxygen-rich staged combustion cycle (ORSC) — that’s been helpful as we look at the AR-1 as well as other rocket engines. ORSC is a cycle that is used in Russia in many of their launch vehicles. It’s not a cycle we had used in this country prior to Atlas 5.
Is the AJ-26 still in the running for future versions of Antares?
I believe Orbital is planning to make a decision within the next month or two but as far as I know AJ-26 is one of the candidates.
Do you have any information on what caused an AJ-26 to fail recently on a test stand?
We’re still in the middle of that failure investigation so I don’t have anything relevant to that.
You absorbed Pratt & Whitney Rocketdyne a year ago. What is its contribution to the whole that is now Aerojet Rocketdyne?
Pratt & Whitney Rocketdyne had a much larger business base in the area of liquid rocket engines, so that was a large part of the add. There’s also some complementary work in the area of missile defense, and some power system work that’s pretty exciting because we’re marrying that with our electric propulsion — they had some power management capability that is very synergistic with what we’re doing. They also had done a lot more work in the area of additive manufacturing than Aerojet had. Also in the area of hypersonics they had a lot of very good capability and that’s another interesting area for the company going forward.
How strong is your business of building solid rocket motors for Atlas 5?
It’s a good business; we probably supply anywhere from eight to 12 motors per year. It’s an attractive feature of the Atlas family where they can provide incremental payload change just by the addition of the number of solids.
Aerojet Rocketdyne is providing propulsion systems for NASA’s Orion deep-space capsule. What role would you have in a European-built Orion service module?
We’ll be supplying some rocket engines to that module and then as that program goes forward, we’re hoping for a long-term role, wherever it gets built.
Are there differences between your propulsion systems on the Orion test flight slated for later this year and those that will fly on the next mission in 2017?
There are some slight upgrades that would occur to the hardware that we would be qualifying over the next few years.
What are some of the other opportunities on the horizon for Aerojet Rocketdyne?
We’re very pleased to see the emphasis on solar-electric propulsion that NASA is discussing for their future architectures. We provide electric propulsion systems to a number of satellite operators and we’ve worked on the high-powered technology that we think is relevant to these future systems. We’re looking at how we can play a different role in the industry as we marry power and electric propulsion. That’s a higher-value subsystem.
It remains to be seen whether NASA’s solar-electric propulsion initiative will get any real traction with the Congress.
It does, but this technology is relevant for any type of mission that you’re going to be doing in space.
The market for satellites featuring all-electric propulsion hasn’t lived up to the hype so far. What’s your view?
We are seeing more than just talk there. We are seeing satellites actually shift to either all-electric or a combination of electric and chemical propulsion. And since spacecraft propulsion is a core business, we do see that as an opportunity and we’re working that very hard. These things typically take time to get integrated into the next architecture. We’re seeing a lot of interest and we’re in the proposing and developing systems phase at this point.
Aerojet Rocketdyne is part of NASA’s Green Propellant Infusion Mission slated to launch next year. Are hydrazine’s days numbered as a satellite propellant?
I wouldn’t say they’re numbered. I think hydrazine plays a very useful role in our industry but there are a number of entities that don’t want to use hydrazine and want us to be developing systems that are nontoxic.
Can green propellant give you the performance and storability of hydrazine?
Yes, it can.
So why continue to use hydrazine?
Green propellant doesn’t have the experience at this point in time. We don’t have the breadth of product capability.
What is the status of Aerojet Rocketdyne’s effort to develop a lower-cost variant of the shuttle-derived RS-25 engine, which will help power the first stage of NASA’s heavy-lift Space Launch System?
We’ve done some planning work and have had some discussions with NASA, and we’re looking forward to getting under contract this year.
What are some of the elements of that work?
This engine was designed 30 years ago, so we can take advantage of modern machining, modern manufacturing. We’ll also look at how we can bring down the cost of certain higher-value components.
How big a contract will that be?
I don’t know that we quote specific contract values.