Delta 4 rocket
Delta 4 rocket. Credit: Lockheed Martin

There is a considerable amount of press these days about how the Russians are withholding the sale of the RD-180 rocket engine for the Atlas 5 launch vehicle, which reduces our defense space launch capability. This is absolutely wrong. 

The Delta 4/Evolved Expendable Launch Vehicles always had the capability to launch all defense space missions from the first day of the EELV. The Atlas 5 never had that total capability because the Atlas program did not bid the heavy vehicle and necessary launch capability out of Vandenberg Air Force Base, California, and Cape Canaveral Air Force Station, Florida. 

It is worthwhile to briefly revisit the background of the EELV procurement that began in the late 1990s.

The original EELV procurement was a winner-take-all competition to replace the then-existing payload launch capability of the Delta 2, the Atlas 2 and the Titan 4. As part of the U.S. Air Force procurement requirements, any major foreign component, such as the RD-180, had to be produced in the U.S. within a specified time period after the award. During this time, the commercial satellite market was robust with many satellite providers and operators bullish on the expansion of the commercial market for communication satellites, especially in low Earth orbit. Iridium was in orbit and Teledesic was planning an 800-satellite low Earth orbit constellation. McDonnell Douglas, now Boeing, and Lockheed were pursuing that market. McDonnell Douglas was pursuing the commercial market independent of the EELV.

The Delta 4 program initially considered using existing Russian engines, both liquid oxygen (LOX)/RP-1 and LOX/hydrogen. However, the Air Force requirement of having to bring manufacturing into the U.S. was a cost and International Traffic in Arms Regulations issue. Overall, the internal launch vehicle trade studies didn’t differ significantly between the LOX/RP launch vehicle and the LOX/hydrogen vehicles. Consequently, the Delta 4 opted for a new, U.S.-built engine utilizing a low-cost gas generator cycle, which satisfied the Air Force domestic production requirement and kept the defense space launch capability within the U.S. 

Rocketdyne was selected to build the 650,000-pound-thrust LOX/hydrogen RS-68 engine. The engine gave a significant performance advantage over LOX/RP with a specific impulse of 410 seconds versus 335 seconds for a LOX/RP engine. Although the Delta 4 program bore the development cost of the engine, which had to be amortized into the recurring cost of the vehicle, the large number of anticipated commercial launches made it competitive. 

Second, the cost of a Russian engine would significantly increase when production in the U.S. was factored in, primarily because Russian pricing is not market-based. Bringing the RD-180 production into the U.S. would also impact the Atlas 5 recurring cost. 

There was some question at the time whether the Russians would release all of the technology related to materials and coatings for the oxidizer cooled, staged combustion engine. Also, stage combustion engines are more complicated than gas generator engines and would be more expensive when built in the U.S.

The Air Force decided to change its procurement approach to the EELV based on the contractors pursuing their commercial launch vehicle families. The service modified its new strategy to include “Assured Access to Space,” meaning using two contractors with significantly different launch systems. This strategy would protect the launch capability if one launch system were inoperable. Rather than have a winner-take-all procurement, it changed to a shared procurement, and the Air Force would become an investor in both contractors’ launch systems. 

The service would invest $500 million in each launch system, a small percentage of the overall development cost. In return, each contractor would provide a launch system that could launch the Air Force total mission model including a heavy-launch capability with launch pads at both Cape Canaveral and Vandenberg. 

After the awards were announced, the Delta 4/EELV met all requirements to meet the Air Force mission model and the Atlas 5 did not.

The robust commercial market started to fade as satellite operators were rethinking the viability of the market partially caused by the bankruptcy of Iridium and the increased capabilities of the cellular system. Soon, the business models of both contractors were in trouble as was the EELV program and Assured Access to Space. 

The Air Force supported the formation of the United Launch Alliance Boeing-Lockheed joint venture and subsidized the large recurring costs incurred by both contractors brought about by the reduced commercial market size. The service relaxed the requirement to bring the RD-180 production into the U.S., which left the Atlas 5 with a large cost advantage, but one dependent on Russian suppliers.

Since the Atlas 5 family cannot launch the full national mission model, the source of the RD-180 does not jeopardize the Air Force’s capability to launch all missions. The Delta 4 can launch all missions, although it would be more expensive because of the U.S.-produced RS-68. If the RD-180 or equivalent is produced in the U.S., it too will become more expensive and the cost differential between the two launch systems will diminish. 

Also, a different engine integrated into the Atlas 5 would incur vehicle and infrastructure development costs to modify and qualify the launch vehicles to the new engine. Although estimates vary, a new, staged combustion engine development program would take about six years and $1.5 billion to $2 billion. Bringing the RD-180 manufacturing into the U.S. would not significantly change those numbers and the engine would have to be requalified. The RS-68 engine development cost about $500 million and took a little less than five years to develop 15 years ago. It is a less-complex engine than the more-complicated staged combustion engine cycle. 

The Atlas 5 RD-180 stockpile is reported to be 15 engines. That should allow time for the transition of more launches to the Delta 4 over a two-year period as production is ramped up. 

A new engine development would not solve the RD-180 problem in a timely manner because of the six-year lead time. Also, stage and launch pad modifications may have to be made. 

It seems probable that since the U.S. is not harmed by the Russians’ refusal to sell the RD-180, they might reconsider the ban and continue a good business for them. The Russians might also think that providing the RD-180 could stop the U.S. from developing a new engine. However, if the Cold War attitude returns and the RD-180 engine is withheld from the U.S., then the impact will be greatest on the Atlas 5 and not on the U.S. defense space launch capability.

The U.S. has let its rocket engine propulsion capability deteriorate by not supporting new engine development, and as a result three major rocket engine companies have now merged into one. The RS-68 is the last major, high-performance engine development and was funded by Boeing’s Delta 4 program, not the government. If the U.S. were to pursue a new engine development, it should not be a 20-year-old RD-180. It should be a new, modern engine designed for today’s manufacturing capability. Because of the timing of a new engine development, and the potential modifications to existing launch vehicle and infrastructure, perhaps a new launch system should be considered.

One conclusion is obvious from the threat of the Russians to stop selling the RD-180 to the U.S.: The Air Force’s strategy of Assured Access to Space to provide two independent launch systems has worked. The loss of the RD-180 does not impede our government’s ability to full access to space because of the Delta 4/EELV capability to meet all Air Force mission requirements.

Dave Schweikle was the Delta 4/EELV program manager at McDonnell Douglas and then Boeing.