Launch vehicle engineers here believe a shuttle-derived vehicle built around the space shuttle main engine (SSME) is probably the fastest route to a heavy-lift launch vehicle. Some kind of heavy lifter is emerging as a centerpiece of the compromise space policy being worked out between Congress and the White House.
But that is only a rough call in a close race with vehicles based on the Pratt &amp; Whitney Rocketdyne (PWR) RS-68 or a kerosene-fueled engine NASA may develop in collaboration with the U.S. Air Force. The internal study of families of heavy-lift launch vehicles based on the three engines is helping NASA managers catalog the capabilities they control as they try to find ways to fit them into the next phase of U.S. space exploration, whatever that turns out to be.
That involves throwing out the carefully crafted approach to what then-Administrator Michael Griffin called the agency’s biggest challenge—managing the transition from the space shuttle to the follow-on Ares I and its Orion crew exploration vehicle—and finding the best way forward in today’s make-it-up-as-you-go-along space-policy environment.
“I try not to react too fast,” says one senior engineer here. “I’ve learned to let it damp out a little first.”
Still, the management at this propulsion center expects to have a role in the long-awaited heavy-lift launch vehicle that seems destined to be the result of the congressional/White House compromise (AW&amp;ST July 19, p. 48). No matter what final details emerge from the push for accelerated development of a heavy-lift launch vehicle, which is being spearheaded by Sen. Bill Nelson (D-Fla.), senior Marshall managers believe a lot of the work logically would be done using some of the same launch-vehicle expertise and facilities that developed the Saturn V, space shuttle main engine and the stillborn Ares I.
One key is the J-2X engine under development here for the Ares I upper stage. Vetting of the J-2X, which is considered by many to be the long pole in the tent for development of the new rocket, continues at Test Stand 116 here because Congress has forbidden the use of Fiscal 2010 funds to shutdown the Constellation project. The injector for the Saturn V upper-stage engine derivative was put through its paces at stand 116, and engineers are wrapping up tests of design changes in its gas generator made to address combustion instability issues. The first full-up engine can be ready for tests at Stennis Space Center by year-end.
Regardless of the first-stage engine selected for a heavy-lift launch vehicle, the 294-lbf. J-2X hits the “sweet spot” for a heavy-lift upper stage, according to J-2X deputy project manager Tom Byrd. The less-powerful RL-10 would have to be clustered to meet that performance, while the RS-68 weighs about three times the 5,000-lb. J-2X and—at 700,000 lbf.—is more powerful than necessary.
Near-term families of heavy-lift boosters identified at Marshall revolve around three basic configurations: an RS-68-powered first stage with a 33-ft.-dia. tank; a throwaway derivative of the reusable SSME already in the concept stage at PWR; and a heavy-lift hydrocarbon engine that would build on work completed by the Air Force Research Laboratory. The SSME-based vehicle would carry a 27.5-ft.-dia. tank (equal to the space shuttle external tank), while the hydrocarbon-fueled stage would use either 27.5- or 33-ft. dia. tanks.
Although an SSME-based vehicle that exchanges the weight of the orbiter for heavy-lift payload capacity probably would be the quickest way to replace the shuttle’s heavy-lift capability, a vehicle using the RS-68 would not be far behind, engineers here have found. The critical question is when the work would start.
“The agency is grappling with what we need right now, depending upon what the budget is,” says Gene Goldman, the deputy center director. “We’re in this period where, as we move forward, if we implement the president’s budget request and his technology development, then it will be some period of time before we need certain skill sets. That begs the question: ‘What do you do and how do you maintain those skill sets in the interim.’”
The skill set is already dwindling. After realizing that the $2.5 billion set aside in the Fiscal 2011 NASA budget request to handle its own costs for shutting down the back-to-the-Moon Constellation program would not begin to cover the termination liabilities faced by the program’s prime contractors, Administrator Charles Bolden estimated that 2,500-5000 jobs would have to be cut this fiscal year to make up the shortfall (AW&amp;ST June 14/21, p. 25).
At Marshall some 500 contractor personnel have been laid off, in part to cover an estimated $144 million termination-liability shortfall in the Fiscal 2010 operating plan for Ares I. Hardest hit in the launch vehicle effort were Ares I upper-stage software development, vehicle integration and other support activities that saw contractors working next to NASA civil servants on design teams.
“We had to replan to accommodate that lesser budget,” says Teresa Vanhooser, who heads up Ares development here. “So we focused on the hardware. Some of the support and integration activities we had to put as a lesser priority so we could keep our hardware moving.”
Compared to the job losses pending at Kennedy Space Center (AW&amp;ST June 7, p. 23), Marshall has gotten off relatively easily so far. Like Kennedy, the layoff numbers here probably will go up when the shuttle program shuts down for good. In its current form the compromise between the White House and Capitol Hill would maintain existing contracts and workforce from the shuttle and Constellation programs “to the extent practicable,” but specifics remain to be negotiated among congressional committees, NASA and the White House.
Even though the total $19-billion request for NASA is holding up on Capitol Hill so far, there is little hope here that the heavy-lift vehicle can support employment at the same level as the shuttle and Constellation projects conducted at Marshall. Many of the jobs here are specifically related to Ares I, such as the friction stir welding facility that is pushing the state of the art in the advanced welding technology while serving as a pathfinder for Ares I production facilities at the Michoud Assembly Facility in New Orleans.
The same holds true for the new seven-axis machine milling facility, which can handle parts as large as 27.5 ft. on its 20-ft. turntable. A lot of the advanced manufacturing capabilities built up for Ares I may be applicable to a heavy-lift rocket, but until its design is started there is no way to be sure.
While not identified as a science center, Marshall has a long history of managing scientific projects that may help it as Congress and the White House try to rebalance the NASA portfolio between robotic and human spacecraft. The Chandra orbiting X-ray telescope was developed here, and the unique vacuum chamber built to test its grazing-incidence mirrors has been modified to handle direct-incidence light gathering as well.
That, and its 20K cryogenic capability, have made the facility invaluable in testing the 18 1.5-meter beryllium mirror segments being crafted for the James Webb Space Telescope. Managers expect that the X-ray and Cryogenic Facility will be maintained for use on future applications, as will other science capabilities scattered across this sprawling field center. Unfortunately for Marshall managers, if not for the nearby city of Huntsville, Ala., the facility is housed on the U.S. Army’s Redstone Arsenal, which is gaining jobs under the Base Realignment and Closure (BRAC) process.
“The Defense Department, Missile Defense Agency and others here in town are going through a process where they’re actually pulling more work in-house, so we have lost a few people to them,” says Dan Dumbacher, head of Marshall’s engineering directorate. “We have also lost people, not necessarily Defense Department civil service jobs, but [some employees] have left NASA to go work for or start up their own companies because of all the BRAC business coming into town. We’ve lost some of our mid-career folks who have experience and a few years ahead of them, and obviously they have motivation. So we have lost good people.”
Some of the authorization language making its way through Congress might help keep those skilled workers on the NASA side of the street at Redstone, directing NASA to make its facilities available to the commercial companies that the White House hopes can take over the job of transporting astronauts to orbit some day.
Jeff Greason, who argued strongly against the Constellation program as a member of the outside review panel headed by former Lockheed Martin CEO Norman Augustine, used the 55-year-old 14-in. transonic wind tunnel here last month to help develop his XCOR Aerospace’s Lynx suborbital spaceplane. The private vehicle, and his entrepreneurial-outsider approach to creating it, epitomizes the commercial “new space” approach to human spaceflight that lies at the core of the Obama space policy.
A senior member of the coterie of NASA critics centered on the airfield at Mojave, Calif., that includes Ansari X-prize winner Burt Rutan of Scaled Composites, Greason even has something sort of nice to say about the government’s civilian space agency, praising the transonic wind-tunnel facility and its staff for helping him to get the data he needs “very rapidly.” That will be the key to future support for NASA, Greason says.
“For NASA to maintain even a constant budget, it has to both serve and be seen to serve stakeholders beyond NASA,” he says.
But Marshall was built by space pioneer Wernher von Braun on the “arsenal model” he first encountered as a young engineer for the Wehrmacht in Nazi Germany. That engineering-heavy approach may not stand up against the Washington policy wonks who believe the commercial approach can be faster, cheaper and just as safe for human spaceflight, leaving more resources for technology development and science.
“The bottom line is going to be that the center is going to be in a little-bit-smaller operating position than it was under the previous budget construct,” Dumbacher says.
By Frank Morring, Jr.
Marshall Space Flight Center