By Sandra I. Erwin
Gen. William Shelton
Administration officials, lawmakers from both parties and space experts stand together on the issue: The U.S. military should no longer rely on a Russian rocket engine for critical space launches.
How to go about replacing the RD-180 rocket engine, though, is now the subject of much study and debate within the U.S. government. And it is becoming increasingly apparent that the effort will take more time and money than politicians in Washington expected. Among the concerns are the timeline and potential cost of producing a substitute engine, as well as the technical challenges of integrating it with existing launch vehicles.
Although deliveries of RD-180 engines still continue as scheduled, the Defense Department and NASA are contemplating a menu of “mitigating strategies” to cope with a potential disruption if the current crisis over Ukraine continues to escalate.
“This is a real concern to us,” said U.S. Air Force Gen. William Shelton, chief of U.S. Space Command.
The RD-180 powers the Atlas V family of space launch vehicles made by the United Launch Alliance, a joint venture of Boeing and Lockheed Martin. ULA has 15 engines on hand. Two more are scheduled to be delivered in August and three in October. Six more would be ordered next year. The engine deal dates back to 1997, when Lockheed Martin inked an agreement with NPO Energomash, Russia’s top manufacturer of liquid propellant rocket engines, to acquire engines for the Atlas launch vehicles. The Pentagon not only depends on Russia for the engine but also for engineering and technical support.
So far, it’s “business as usual,” Shelton said July 22 at a Pentagon news conference.
Other than off-the-cuff threats by Russian Deputy Prime Minister Dmitry Rogozin, there is no factual indication that supplies are being cut off, he said.
If the situation deteriorates, the Pentagon is preparing contingency plans to deal with engine shortages, said Shelton. If and when engine supplies might be disrupted is still unknown. “How are we going to proceed in our relationship with Russia at this point? This is a question for the nation’s leadership,” he said. “The events of the past two weeks certainly aren’t confidence builders.”
The current supply of RD-180s would last about two years if every launch in the government’s manifest is executed, said Shelton. Among the available options if supplies were cut off is to stockpile the engines and delay some launches. The engines have to be shared with NASA and the National Reconnaissance Office, so a high-level decision would be needed to allocate them. If satellites have to be parked indefinitely as they wait for launch availability, the cost of storing and maintaining sensitive spacecraft on the ground could range from $1.5 billion to $5 billion.
Another option is to ramp up production of the more expensive Delta IV rocket engines, which are manufactured domestically. Shelton estimated that would cost about $1.5 billion. The addition of newcomer SpaceX as a provider of military space launches also could help fill the gap, but the company’s rockets are not expected to be certified to fly military payloads until next year. The possibility of developing an engine comparable to the RD-180 in the United States also is on the table.
“This is a hydra headed monster,” Shelton said of the task the Defense Department faces.
Shelton said he would like to see the United States build a rocket engine comparable to the RD-180, but cautioned that it would be a tall order. The U.S. government and industry have lagged in liquid rocket propulsion research and manufacturing, said Shelton. “I don’t think we build the world’s best rocket engine.” The RD-180 is the best in advanced materials, performance and thrust-to-weight ratio, he said. “I would love for us as a nation to regain the lead in liquid rocket propulsion.”
Whether the effort would be led by the government or the private sector, or both, is part of the ongoing discussion.
“We’ll know more in the next couple of months,” said Shelton. “We still have in the United States some expertise in liquid rocket engines.” But no new rocket engine has been built domestically since the early 2000s. “That doesn’t bring in the new talent,” he said.
The Senate Armed Services Committee approved $120 million, and House Armed Services $220 million, to begin the development of a new engine. But many more billions would be needed to bring it to fruition, experts said last week at a joint hearing of the Senate Armed Services and Commerce, Science and Transportation committees.
Shelton and other space officials offered lawmakers a sobering reality check.
“We could develop an engine with sufficient time and money,” said Daniel Dumbacher, professor of practice at Purdue University Department of Aeronautics and Aerospace Engineering. “There are development risks. ... There are technical issues to be addressed. I think we can overcome those but it's a matter of time and money required to do that.”
Principal Deputy Defense Undersecretary for Acquisition, Technology and Logistics Alan Estevez said it would take up to eight years and $2 billion to develop a new engine. “We're looking at this as a whole-of-government issue,” said Estevez. “We would look at what NASA capabilities are, as well as what we have inside the Department of Defense, and what the commercial sector is also doing,” he said. “We haven't decided what the best way forward is.”
Retired Air Force Maj. Gen. Howard “Mitch” Mitchell recently offered several recommendations for how to tackle the engine shortage, including major investments in research and development and a deeper examination of the technologies available in the commercial space industry.
“There are some risk reduction activities to bring the technology levels up in hydrocarbon engines that need to be invested in,” he said. “That will take a year-and-a-half or so, or two years to bring those technologies up. ... The risks have to do with the materials, they have to do with the modeling of the combustion instability, and some of the parts of the engine itself, injectors and other components that need to be matured.”
Mitchell’s study concluded that a disruption of RD-180 deliveries would have a significant impact on the U.S. ability to launch on Atlas V through 2020. “Neither the Delta IV nor new entrants can help mitigate that impact until 2017 and beyond,” he said. In the 2022-2023 timeframe, with “appropriate near-term funding for technology maturation, the nation could have new launch capabilities based on liquid oxygen/hydrogen engine technology that do not rely on foreign sources.”
Even if a new engine were designed successfully, its integration into existing launch vehicles could be a daunting challenge, said Robert Lightfoot, NASA associate administrator. “We have to look at the impacts on not just building an engine and having an engine to use but the impacts on the launch, the infrastructure that goes around that,” he said. “Can we do it? I'm sure we can, with the right resources ... but I think we have to make sure we understand the other pieces that come with that as we go forward.”
Dumbacher warned that the U.S. government’s spotty track record with space programs could result in further delays and rising costs as this technology quest moves along. He suggested greater private sector involvement and competition to keep pressure on costs.
“The U.S. leads the world in these propulsion systems. However, we need to reduce the costs of these systems,” he said. “In my opinion, the United States should build upon its long investment in solid and liquid oxygen/liquid hydrogen propulsion systems, and allow the marketplace to provide viable choices for use by NASA and the Department of Defense,” he said. “Competition will incentivize industry to develop efficient management models, use the new technologies that will reduce costs, and continue to search for and develop technologies necessary to reduce development and operations costs.”
The Government Accountability Office estimated that defense and civilian government agencies expect to require nearly $44 billion for the next five years for launch activities. GAO analyst Cristina Chaplain cautioned that programs could benefit from greater efficiency. “Our past work has found that launch acquisitions and activities have not always been well-coordinated, though the Defense Department and NASA have made progress on that front,” she said.
A new Air Force study scheduled to be completed in September will recommend the most “affordable — within a time frame — course” for a new engine, said Estevez. It will consider public-private partnerships, internal government development and commercial outsourcing.
Shelton said a domestic engine program would be a boon for the industry. “I think we can certainly help our liquid rocket engine industrial base by moving into such a program. I think we need to study the requirements. I think we need to look at what kinds of technologies we need to develop.”
The Mitchell review concluded that nobody in the public or private sector has all the necessary technology ready to start a full-scale development program. “We think that that's going to take some investment and time to get the technologies up to where you could actually do a full-scale development and commit to actually procuring a new engine.”
As to who ultimately will decide when to move from the RD-180 to another engine, that also is unclear, Shelton noted. “I would speculate that what would happen is the executive branch would bring a proposal to the Congress, and then the Congress ultimately has to decide whether or not to spend the money.”
Photo Credit: Air Force