Aviation Week & Space Technology, 09/26/2005, page 22

Frank Morring, Jr., Washington

In 1962, President John F. Kennedy rallied Americans to back his goal of putting a man on the Moon before the end of the decade, and they did. Whether citizens and Washington lawmakers will support a proposed return is questionable in an era of competing domestic programs, a costly war on terrorism and ballooning federal deficits. A detailed, inside look at NASA's ambitious plan is described in "Moon-Bound, Again." Articles on propulsion technology that could be employed in the new Moon mission (p. 24) and the challenge for contractors competing to replace the space shuttle (p. 26) follow, as does a thought-provoking guest commentary (p. 28) and editorial (p. 70). Artist concepts of mission elements are from NASA/John Frassanito & Associates.

Mars may be the ultimate target, but continued strong U.S. leadership in human spaceflight is the stated goal of NASA's tightly focused new plan for lunar exploration.

A rigorous scrubbing over the summer held the cost of a return to the Moon as a first step to the Red Planet to what NASA says is 55% of the cost of the Apollo program in inflation-adjusted dollars.

Still, despite making lavish use of hardware developed during the past 45 years, it will cost an estimated $104 billion to keep the U.S. in the critical path back to the Moon by 2020.

That's a breathtaking number, even when spread out over two decades. And the "go as you pay" approach set by the Exploration Space Architecture Study (ESAS) outlined last week also leaves plenty of room for international and commercial players to add their money in the years ahead.

The plan has already been targeted by conservative Republicans looking to pay the massive hurricane recovery bill coming due. NASA Administrator Michael D. Griffin defends the price tag as the cost of maintaining the "strategic" U.S. ability to send humans into space after the shuttle is retired at the end of 2010.

"The House passed by a very wide margin a bill that said we want to go ahead and do this, and the Senate presumably will pass a bill relatively soon that will do the same," says David Goldston, chief of staff of the House Science Committee. ". . . At this point I haven't seen Congress say 'oh, we shouldn't be doing this because we've got these other expenses.'"

NASA's expenses will be spent on Earth, at its field centers and traditional contractors with long-standing support on Capitol Hill. The plan also includes seed money for a complete new commercial space industry. Griffin says the space agency will launch a procurement "this fall" to stimulate commercial resupply and ultimately crew delivery to the International Space Station (ISS), drawing on a $500-million wedge in NASA's funding proposal for the purpose (AW&ST Sept. 5, p. 31).

The new approach also invites international partners to follow the ISS model in developing hardware and support for human exploration of the Moon and ultimately Mars. While the ISS partnership remains roiled by the potential impact of the Columbia accident on the ultimate station configuration, would-be partners certainly don't want to shut the door on the new opportunity to explore. Indeed, Europe's EADS and Alenia are already working on the planned Crew Exploration Vehicle (CEV) as members of competing U.S.-led contractor teams (AW&ST Jan. 31, p. 28; Feb. 7, p. 30).

"We respect that in the critical path to space, NASA and the U.S. want to be autonomous," says Gerhard Thiele, head of the European Space Agency astronauts and operations unit in Cologne, Germany. "It is too early to tell [but] once the dust settles. . . . I'm sure we in Europe, where we have great strength in scientific endeavors, will find opportunities to cooperate on the Moon program."

The lunar launch vehicle Griffin is pushing--actually two versions of the same concept--is based to a large extent on propulsion technology developed for the space shuttle (see p. 24). It was chosen to hold down costs in meeting President Bush's space policy by making maximum use of existing technology and infrastructure.

While the near-term focus of the ESAS plan aims at reaching the Moon by the summer of 2018, an integral part of the space transportation architecture to get there is a new methane-fueled rocket engine that was included solely with Mars exploration in mind, according to Douglas Stanley, a member of the aerospace engineering research faculty at Georgia Tech brought in by Griffin to lead the ESAS team of exploration experts.

Basically the architecture can be divided into three parts--a near-term effort to replace the space shuttle in the existing space infrastructure; expansion of that infrastructure to the lunar surface, and an eventual push on to Mars that is so undefined that there isn't even a date for a Mars mission.

"We've not gotten out that far in our planning," Griffin says.

In the near term, NASA expects to award a contract by April 2006 for a CEV capable of carrying as many as six astronauts to the ISS and four to the Moon. Dubbed "Apollo on steroids" by Griffin, the solar-powered CEV will include a crew capsule, a service module carrying the new methane engine and a solid-fuel pull-off tower for crew rescue. Two contractor teams--one led by Lockheed Martin and the other by a Northrop Grumman/Boeing combination--have been working on the project since July 11, and will refine their original CEV proposals to meet a "call for improvements" set for release next month that will incorporate the ESAS results (see p. 26).

In parallel with the CEV development, NASA intends to start work on the first of two shuttle-derived launch vehicles that have been widely discussed in concept. The Crew Launch Vehicle (CLV) would carry the CEV toward orbit atop a single shuttle booster consisting of four segments as in the shuttle stack. A new upper stage, to be competitively developed beginning early next year, would use one space shuttle main engine (SSME) to finish the ascent.

Beginning as early as 2012, the CEV/CLV stack would begin flying from the existing shuttle launch pads at Cape Canaveral, taking crew to and from the ISS. The CEV would also be able to carry as much as 7,000 lb. of pressurized cargo to the station or 25 metric tons of unpressurized cargo to a "station-compatible orbit" in automatic mode.

As the CLV development starts wrapping up in mid-2010, the new plan calls for NASA to begin developing the three additional spacecraft it will need to send humans back to the Moon. Again, shuttle hardware will be critical, starting with the SSME. Selected for its relatively light weight and high performance compared to other engines available, a cluster of five SSMEs would propel a 125-ton-class lunar heavy lifter that will get lunar mission infrastructure into orbit.

The engines would ride at the bottom of an extended version of the shuttle external tank, and two five-segment versions of the shuttle solid boosters would provide added lift. Plans call for both the CLV upper stage and the lunar heavy lifter to be built at the Michoud Assembly Facility on the outskirts of New Orleans, where the shuttle external tanks are built today.

THE EARTH-DEPARTURE stage would be powered by two simplified versions of the J-2 LOX/hydrogen engine that powered the upper stages of the Saturn V moon rocket during the Apollo program. It would serve both as an upper stage on ascent, and be restarted to begin the three-day trip to the Moon.

If all the developments come together on schedule, by the summer of 2018 NASA would be ready to launch four astronauts on the first lunar landing mission since December 1972. The "one-and-a-half launch" concept would see the heavy lifter put the lunar lander and Earth-departure stage in orbit, followed within 30 days by the CEV/CLV with the crew. The CEV would dock to the top of the lander, and the departure-stage engines would be reignited to send the crew on the way to the Moon, riding backward.

Once in lunar orbit the entire crew would descend to the surface in the lander, leaving the CEV in orbit. Unlike Apollo, which was restricted to the lunar equatorial regions, the new lander would be able to reach any point on the Moon's surface, including the poles where water ice may lie hidden in deep craters. The first surface stay would last seven days, although the CEV could remain in lunar orbit for as long as six months while its crew worked below.

At the end of surface operations the crew would fire the methane engine and return to a lunar-orbit rendezvous with the CEV. The notional plan calls for leaving airlocks and other hardware and consumables on the descent portion of the lander that could later be used to build up a human-tended lunar base.

In orbit the crew would dock with the CEV, discard the lander for eventual impact on the surface, and fire the service module methane engine for the return to Earth.

NASA has specified a parachute recovery after the ballistic CEV capsule reenters the Earth's atmosphere, but the agency will leave it up to the contractors to propose how to handle touchdown on dry land, probably at a military range in the West. The vehicle must also be able to handle a water landing.

In addition to the human return to the Moon, NASA envisions a parallel program of robotic lunar exploration that will include the Lunar Reconnaissance Orbiter already underway and at least one robotic lander after that. While NASA would retain ownership over all hardware needed to get humans to the Moon and back, the ESAS plan envisions international participation along the lines established in the ISS program.

Those include sharing data from robotic lunar surveys; cooperation on developing surface habitats, rovers and equipment for power, logistics and science.

THAT SAME MODEL would apply for an eventual mission to Mars. NASA's initial idea is to use a 100-metric-ton-class heavy lifter like the shuttle-derived lunar heavy lifter to send four or five assembly flights to low Earth orbit. It would also be used to start pre-positioned habitat, power, communications and an ascent/descent vehicle on their way to the planet.

Six crewmembers would make the 180-day round trip in a dedicated crew transit vehicle, and spend 500 days on the surface exploring, conducting scientific investigations and extracting oxygen, water and methane from the environment. The CEV now under development would still be around, held in Earth orbit to return the crew to the surface at the end of their mission.

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World News & Analysis

Aviation Week & Space Technology, 09/26/2005, page 24

Frank Morring, Jr., Washington

Shuttle main engine, solid boosters baselined in Moon plan, along with new methane rocket

Rocket engines from across the history of the U.S. space program would power NASA's new exploration plan, along with a new development that could draw its fuel from the atmosphere of Mars.

Planners on the Exploration Systems Architecture Study (ESAS), released last week, chose the Pratt & Whitney Rocketdyne space shuttle main engine (SSME) and the ATK reusable solid rocket motor (RSRM) to do the heavy lifting on the way back to the Moon. The idea was to save the time and money of new development.

But one new concept--a methane-fueled rocket--is central to President Bush's January 2004 order to move human exploration out of low Earth orbit (LEO) and use the Moon as a stepping-stone for a trip to Mars. U.S. enginemakers will be asked to build a pressure-fed engine that burns liquid oxygen (LOX) and liquid methane, first to power the Crew Exploration Vehicle (CEV) under development to haul astronauts around the Earth-Moon system (see p. 26) and later to blast them off the surface of the Moon.

Ultimately, NASA hopes to produce methane fuel on Mars to save weight on the outward journey to the red planet. That way, a mature version of the engine originally developed for the CEV and lunar lander could be applied to Mars exploration as well.

"Aerojet's done some stuff with NASA Marshall about 15 years ago, but that was larger thrust and there was more workhorse equipment," says Todd Neill, chief engineer for space exploration at the Sacramento-based propulsion house. "So I think the whole U.S. industry is on a pretty steep learning curve with methane propellant at this point."

ESAS planners would like to see industry develop a dual-use methane engine in the 15,000-lb.-thrust class. The engine could get a thorough shakedown in LEO on CEV missions to the International Space Station starting in 2012 and, if successful, could be considered reliable enough to serve as an ascent engine on the lunar lander beginning in 2018.

As a backup, the exploration plan allows for hypergolic engines in both applications if a workable methane engine isn't available. Although final CEV procurement plans won't be released until next month at the earliest, the two contractor teams already working on the new vehicle--headed by Lockheed Martin and Northrop Grumman/Boeing--are expected to be asked to include a methane engine in their designs for the CEV service module.

The CEV contractors will also need new solid-fuel rocket motors for the escape system that would pull the crew off its launch vehicle and out of the way during an ascent catastrophe. ATK and Aerojet are expected to compete for that work as well, but ATK already has the big solid-fuel exploration element in the bag with the RSRM.

The Crew Launch Vehicle (CLV) for the CEV will consist of a single, four-segment RSRM topped by a new upper stage. Once the CLV is developed, NASA plans to turn its attention to a shuttle-derived heavy lifter that uses two five-segment RSRMs as strap-on boosters. ATK has already tested the five-segment version on the ground (AW&ST Nov. 3, 2003, p. 17).

Power for the CLV upper stage and the core stage of the heavy lifter will be supplied by the SSME. The ESAS team chose a single SSME for the new upper stage, modified for ignition at altitude, and a cluster of five for the heavy lifter. The SSME version for the CLV is essentially already flying on the space shuttle fleet.

"What we will be doing there is basically a test program to validate and verify our new start box, because we'll be starting two minutes into flight," says Steve Cook of Marshall Space Flight Center, who was in charge of launch vehicle planning on the ESAS team. "What we've got to look at there is the engine thermal conditioning, the engine pre-start purging, and what the engine start sequence is. It's been looked at twice in a good bit of detail in about the last 10 or 12 years."

Because it won't be needed until well into the next decade, there will be room for improvements to the SSME used on the heavy-lift vehicle. Coatings needed to protect engine parts over multiple shuttle missions may be eliminated in the throwaway single-use heavy-lifter version, says Byron Wood, president of Pratt & Whitney Rocketdyne; and cost savings can be achieved by using the hot isostatic press (HIP) process developed for the RS-68 engine to craft the combustion chamber and perhaps the nozzles.

"The key thing in all of those proposals will be the tradeoff between what you spend for recurring costs for a throwaway engine versus the nonrecurring costs to recertify a new process," says Wood.

Even without improvements, Wood sees a "significant reduction" in the cost of an SSME when the Canoga Park, Calif., factory begins producing them at the planned rate of six a year. The plant currently produces the equivalent of one a year in spare parts, he says. The exploration program will also save money by using up the almost 30 engines in the shuttle program, either on orbiters or as spares and support hardware.

Two venerable U.S. rocket engines round out the hardware in the ESAS plan. For descending to the lunar surface the team baselined a throttleable RL10-class LOX/hydrogen engine like the RL10A-5 engine used on the DC-X and DC-XA testbeds in the 1990s. And to get to the Moon, the team picked the latest version of the Rocketdyne LOX/ hydrogen J-2 that powered the Saturn V upper stages. Tested on the ground for about 31,000 sec. but never flown, the 265,000-lb.-thrust J-2S was simplified with a tap-off design to eliminate the gas generator on the J-2.

Two J-2S engines would power the Earth-departure stage launched atop the shuttle-derived heavy lifter. They would fire once to complete the ascent to LEO, and later be restarted to push the lunar lander and CEV to lunar orbit.

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