PWR Offers Shuttle Engine Alternative
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By Joseph C. Anselmo
Pratt & Whitney Rocketdyne (PWR) says it could rapidly stand up an expendable space shuttle main engine (SSME) if the Obama administration decides to use a shuttle-derived throwaway heavy lifter as an alternative to the Ares I crew launch vehicle.
The company has told a White House panel reviewing human spaceflight options that it could have a sufficient number of SSMEs ready within a year using a combination of leftovers from the shuttle program and newly-built engines. It has also proposed developing a modified, lower-cost SSME as a follow-on, PWR President Jim Maser said July 14 at a Space Foundation roundtable in Washington.
Maser stressed that PWR is not advocating any particular launch vehicle architecture to the study panel, which is headed by former Lockheed Martin CEO Norman Augustine. "We're assuming any solution they choose would have some liquid propulsion in it ... We're ready to support any architecture they recommend," he says.
The idea of using an expendable shuttle-derived lifter was raised by shuttle program manager John Shannon at a public meeting of the Augustine commission last month (Aerospace DAILY, June 19). Maser says that if that option were selected, PWR will have 14 leftover SSMEs that are completely flight worthy. "Those 14 are already paid for, so for future budgets they're free," he says. Another engine that has been fully assembled but not tested, plus spare parts, could raise the total to 17.
The company also would manufacture additional engines using the existing SSME design while beginning work on a modified design that incorporates advances in the construction of nozzles and combustion chambers. That would be ready to go into production within 3-4 years. Maser estimates the modified SSME would cost two-thirds to four-fifths of the original model - depending on the number ordered - and would be "a little more expensive" than the company's RS-68 engine "but in that ballpark."
Maser says Rocketdyne also has briefed the Augustine panel on the status of its J-2X upper stage engine, which completed a critical design review last November and remains on schedule. "We could be going even faster, but because of funding restrictions and [other] priorities we've been asked to slow down a little bit and stretch our program out," he says. PWR is recommending that J-2X development continue, but has also told the Augustine panel that it could develop a different-sized upper-stage engine if needed.
The Augustine panel is scheduled to deliver its recommendations by late August. Maser says any hope of getting a boost in funding for human spaceflight rests with the White House, which would have to lead the charge. But he is not optimistic that will happen. "All the indications we're getting from the executive branch is that funding is going to be pretty tight," he says.
But even if that is the case, the Obama administration can help by implementing a long-term space road map that is consistent and predictable so companies can plan for hiring and R&D investments, Maser says. He notes that a push-out of the massive Ares V cargo launch vehicle would open a development gap that will make it difficult for propulsion companies to retain skilled workers and capabilities. "Maintaining the critical skills to continue these developments through peaks and valleys is a real challenge for the industry," he says.
Space shuttle main engine photo: NASA
