WASHINGTON — U.S. President Barack Obama has said NASA willspend the next five years studying new technologies and materials beforesettling on a heavy-lift rocket design. But NASA documents and comments fromagency officials suggest the White House already has a design firmly in mind.
On May 3 NASA issued a request for information that givesU.S. aerospace firms roughly three weeks to volunteer ideas for a versatile,liquid-fueled heavy-liftrocket that incorporates a first-stage engine that burns a mixture ofliquid oxygen (LOX) and kerosene to produce at least 1 million pounds ofthrust.
The document also requested industry input on an in-spaceengine demonstration program that would focus on flight testing a newLOX/hydrogen or LOX/methane upper-stage engine that could be used on theheavy-lift rocket.
A few hours later, NASA posted a revised solicitation thateliminated all references to LOX/kerosene or any other specific liquidpropellant and now gives industry the leeway to submit information on a widerrange of heavy-lift architectures that could meet NASA, U.S. Defense Departmentand commercial needs.
Cris Guidi, deputy director for NASA's Constellation SystemsDivision, said the initial request for information — drafted in response toWhite House budget guidance — was posted by mistake. "The guidance that weoriginally received based on the president's budget submit was to focus on alarge LOX-hydrocarbon engine," Guidi told Space News May 7. Sheadded that the White House felt that a LOX/kerosene first-stage engine would bemore affordable than other propulsion capabilities, including the type ofsolid-rocket motors used on the space shuttle and long planned for the Ares Iand Ares V rockets thepresident has marked for cancellation along with the rest of the moon-focusedConstellation program.
But Guidi said after several "meetings and negotiations"with the White House Office of Management and Budget (OMB) and Office ofScience and Technology Policy (OSTP), it was clear the president's primary goalwas to lower the cost of launch. Now, with the modified solicitation in mind,Guidi said NASA intends to evaluate myriad heavy-lift concepts and base itschoice on cost and reliability.
"We're going to go with the most affordable system,"she said. "And OMB and OSTP actually agreed to that."
OMB spokesman Tom Gavin said May 7 "the primary focusfor first-stage propulsion [research and development] under the new effort ison hydrocarbon engines that are likely to play a key role in an affordable andsustainable heavy-lift rocket, as well as potentially in future rockets forcommercial and national security purposes."
Gavin said NASA also will fund "foundational propulsionresearch" that could address a wider range of rocket technologies andpropellants, including solid propellants.
Guidi said studying the spectrum of heavy-lift engineoptions helps NASA remain in compliance with a law passed in December thatrequires the agency to keep working on Constellationuntil Congress explicitly approves a new direction. Lawmakers opposed to abandoningConstellation have accused NASA of slowing work on the program in preparationfor pulling the plug later this year.
"NASA is currently in a very odd position that we arestraddling [fiscal 2010] appropriations as well as what the presidentrecommended for [fiscal 2011], which has not been approved," she said.
In the meantime, Guidi said the broader study of engineoptions leaves the door open for a future heavy-lift architecture thatincorporates solid-rocket motors, an option that should help appease lawmakersseeking to sustain the U.S. solid-rocket-propulsion industrial base.
"Is there a future? Possibly," she said. "Again,it all depends on the vehicle concepts we study, and how they pan out as far asfrom an affordability figure of merit."
Two days after NASA posted and then revised an RFIspecifying a LOX/kerosene engine for the nation's next heavy-lift launcher,Guidi's boss — NASA deputy associate administrator for exploration systemsLaurie Leshin — briefed an industry gathering here on a plan to develop aLOX/kerosene prototype engine by 2016 and field an operational version by 2020.
But Guidi said that plan is likely to change in light ofObama's April 15 call for NASA to finalize a heavy-lift rocket design no laterthan 2015 and then begin to build it.
"The original guidance we got Feb. 1 was purely justengine development," Guidi said, referring to NASA's 2011 budget request.
Guidi said the White House also expects NASA to focus onpropulsion development that could satisfy multiple customers, including theDefense Department, which currently relies on Atlas 5 and Delta 4 rocketsoperated by Denver-based United Launch Alliance.
"The whole reason for that is so that the governmentgets the best price," she said, adding that the Defense Department wouldbe closely involved with NASA's heavy-liftdevelopment plans. "We're going to do this system analysis jointlywhere we're going to determine what's the best approach and does it make senseto have a common upper stage between NASA and Air Force."
Guidi said that if NASA chooses to pursue development of aliquid first-stage engine, the goal would not be to produce a U.S. clone of theRussian-built RD-180 engine currently used to power the Atlas 5.
"Our goal is not to replicate the RD-180, our goal isto build a hydrocarbon engine that both NASA and [the Defense Department] andhopefully commercial can use," she said, adding that NASA and the Pentagonwould study thrust levels and other engine characteristics capable ofsatisfying civil, military and commercial needs. Guidi said NASA is looking foran engine that would exceed the 860,000 pounds of thrust the kerosene-fueledRD-180 delivers.
"We're not Americanizing the RD-180 is the bottom line,but we are building a large hydrocarbon engine," she said.
Guidi said the goal of NASA's heavy-lift research anddevelopment effort — budgeted at $3.1 billion between 2011 and 2015 — is tomake space launch more affordable, not necessarily produce the kind oftechnological breakthroughs called for in other parts of Obama'sspace exploration plan.
"It's to drop the cost of launch, and the propulsionsystem is the predominant cost factor in any launch system," she said. "Butit's more to stabilize the industrial base and maintain the critical skills ofpropulsion-system development in the U.S."
While NASA is not ruling out building a heavy-lift solutionthat incorporates solid-rocket motors, Guidi said affordability, reliability,and the flexibility to serve multiple users are paramount.
"Obviously we don't have the budget to maintain thecurrent course of Constellation," she said, adding that the Ares V design— promising more lift than the Apollo program's Saturn 5 rocket — emphasizedperformance over cost. "Our goal is affordability. Let's not build thatMaserati. Let's make do with maybe a Toyota, as long as we get our missionaccomplished in an affordable, reliable, operable manner. That's our bestapproach rather than having a system that operates on the margins and is veryintricate."
Whether Ares V — or something like it — makes the cutremains to be seen.
"That's not to say that an Ares V may not fall out tobe a more affordable option than" a LOX/kerosene option, she said. "That'swhy we wanted to open up the trade space and say, 'Let's not just focus on[LOX/kerosene]. Let's do the entire spectrum now that we've got a new focus on affordability.'And if we find that some options just continue to be too expensive for us, wejust won't address them."
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