NASHVILLE, Tenn. — The U.S. must overcome the growing challenges of rising launch costs and aging propulsion systems if it is to gain much needed efficiencies and maintain its global lead, warns Gen. William Shelton, commander of Air Force Space Command.

Making the case for urgent action in the face of severe budget cuts, Shelton argues strongly in favor of the development of new main and upper-stage engines, which he believes are pivotal to the future of U.S launch capability. Speaking at the American Institute of Aeronautics and Astronautics New Horizon Forum here, Shelton says “to get better in space launch we need newer, more efficient engines to enable much more robust access to space.”

Although the past 81 consecutive national security launches mark “an unprecedented record” for U.S. space launch, Shelton says “we pay a huge financial premium for that success.” Alternatives must be found to offset these costs, he adds. “Don’t get me wrong. I’m not suggesting we want to do launch on the cheap, but there are places we can look to reduce costs without affecting our sterling record of success,” he says.

Speaking specifically about the RS-68 and RL10 engines that form the propulsion backbone of the current Evolved Expendable Launch Vehicle (EELV) launcher fleet, Shelton says “the RS-68 was designed about 20 years ago and the RL10 was originally designed back in the 1950s — for technology that’s pretty doggone old.” And the upper-stage engines are “red-lined on just about every launch we do, running at 25% over the originally designed chamber pressure,” he adds. “I’ve said for years that the person or company or person who finds a breakthrough in space propulsion will become very wealthy. It’s got to happen because it’s just too expensive to get hardware and people to orbit.”

Shelton says the knock-on effect of more efficient, less costly engines will affect the entire launch cost equation. “Now imagine what design trades we could make if it was an order of magnitude less costly to get to orbit. We’d have less complex, smaller satellites and hence smaller launch vehicles,” he says.

Although engine performance is currently adequate, Shelton believes the real benefits could be found in improving manufacturing processes, which he adds “leave a lot to be desired.” Citing the Pratt & Whitney Rocketdyne RL10, he says each engine “requires more than 8,000 man touch hours — more than a hand-built Lamborghini if you can believe that.”

Although the requirements for the Air Force’s ongoing new-upper stage engine are yet to be fully defined, Shelton says “I expect it will be much easier to manufacture to significantly reduce our costs and it should also have increased performance so we can operate at reasonable margin. Increased reliability also reduces mission assurance concerns.”

In the meantime, Shelton says other cost-savings continue to be developed, including the new block-buy strategy for EELV. The Air Force also is “working with [EELV manufacturer United Launch Alliance] to identify other savings and is in the midst of due diligence to reduce launch costs with our current launch vehicles.” One such move includes launching multiple payloads per vehicle. “We recently decided we’ll launch future GPS satellites two at a time where it makes sense, and it’s a great way to save on overall launch costs,” he says.