The Outer Limits

On Independence Day, the Pathfinder spacecraft landed in an ancient flood plain and introduced earthlings to the rocky red surface of Mars.

The $250-million interplanetary project also served to introduce Americans to a new NASA--a space agency concerned not only with the Big Bang but also with getting the biggest bang for its buck.

But that was old news to the folks at Dryden Flight Research Center, where engineers are designing and testing some of the country’s most cutting-edge flying machines. This outpost of the National Aeronautics and Space Administration on the southwestern edge of the Mojave Desert is thriving on the kinds of “faster-better-cheaper” projects championed by NASA administrator Dan Goldin.

Although NASA’s budget has shrunk nearly 10% since 1991, Dryden is the only one of the agency’s nine centers experiencing substantial growth. With a comparatively trim annual budget of $154 million, Dryden’s corps of engineers is carrying out nearly 30 projects, many of them in cooperation with private companies. In fact, the goal is for much of the technology being tested here to reach fruition as part of the commercial aerospace industry.

In its 51 years, Dryden has made a name for itself by pioneering supersonic flight, creating the first planes with voice-activated controls and developing the digital fly-by-wire flight control systems that now substitute for mechanical controls in most military planes and some commercial aircraft.

Today, even though it behaves more like a business and less like a government lab, Dryden is still churning out high-tech airplanes and spaceships. This month it will begin preliminary flight tests on a vehicle known as the X-38, designed to return astronauts to Earth from the International Space Station--which will begin to take shape in orbit next year--in the event of an emergency.

The windowless fiberglass vehicle--which, with its white paint and black heat-absorbing tiles, bears a strong resemblance to famed killer whale Shamu--can hold six astronauts and ferry them to land on autopilot in about eight hours.

“They get in, close the hatch and separate from the station,” said Chris Nagy, Dryden’s chief engineer on the project. “Then the computer takes over and guides them into orbit.”

The X-38 will circle the Earth once or twice before using a rocket to turn around, slow down and sink into the atmosphere. The computer system that runs the vehicle will use data from global-positioning satellites to guide it to one of six designated landing sites.

A series of parachutes will slow the X-38’s descent to about 35 miles per hour and allow the computer to steer it to a runway. The 14,000-pound craft will slide to a stop on three ski-like skids. Eventually, the computer will be accurate enough to land the X-38 on a football field, Nagy said.

NASA economized on the X-38 by using the shape of an experimental vehicle from the early 1970s that had already endured detailed aerodynamic and heating tests. Although NASA provided the specs for the X-38’s shape and main flight systems, the agency left it to engineers at Scaled Composites of Mojave to design the mechanical systems that control the vehicle’s parachutes.

The specialized design work was done while the vehicles were under construction, allowing Scaled Composites to complete the project in only eight months, said Chuck Richey, the company’s X-38 project engineer. With a budget in the neighborhood of $80 million over four years, the X-38’s cost was “very little by aerospace standards,” said Bob Williams, Scaled Composites’ X-38 program manager.

“This was a milestone for working with a government agency as far as flexibility and the ability to make decisions and get the job done,” Richey said.

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Another example of Dryden’s combination of high technology and down-to-earth business sense is the Hyper-X, an unmanned, wingless plane that will test the boundaries of supersonic flight 100,000 feet up. Paul Reukauf, chief engineer for the Hyper-X project at Dryden, envisions supersonic planes as big as Boeing 747s that can carry passengers on trans-global flights in just a few hours, as well as smaller, more maneuverable military models.

As part of the five-year, $155-million program, Dryden will test four Hyper-X planes built to fly between five and 10 times the speed of sound--about 3,375 to 6,750 mph, depending on atmospheric conditions. By comparison, the Air Force’s super-fast SR-71 Blackbird cruises at a mere 2,000 mph.

Hypersonic airplanes have been on drawing boards since the 1960s, but the technology required to propel them has come of age only recently. Aircraft engines normally burn a mixture of fuel and oxygen in much the same way a typical automobile engine does. But at altitudes of 100,000 feet, the atmosphere is so thin that oxygen is hard to come by.

Military planes get around this problem by carrying an oxidizer (a component that mixes with fuel to make it combustible), but the extra weight is a hindrance. NASA engineers expect the Hyper-X to get the oxygen it needs from the thin air of the upper atmosphere. If the plane flies fast enough, they figure, it will pass through enough air to collect the needed amount of oxygen.

The Hyper-X will compress that oxygen by harnessing the power of the shock waves that are a byproduct of breaking the sound barrier. The underbelly of the plane--a sleek, aluminum structure that resembles a surfboard with twin tail fins--was designed with a series of precise curves to compress air to about 95 times its original density.

The rectangular copper alloy engine beneath the Hyper-X’s midsection will run on pure hydrogen, the most potent fuel around. After the hydrogen mixes with the compressed oxygen and burns, the pressure from the expanding gas will propel the plane forward.

To reach its cruising altitude, the Hyper-X will be attached to a rocket booster and ferried at least 18,000 feet high under the wing of a B-52. Then the rocket will be released to carry the Hyper-X nearly 20 miles above ground.

Much of the Hyper-X’s design was taken from designs for the National Aerospace Plane, a 1980s project to build an aircraft that could take off on a runway and fly all the way into orbit. The project fizzled a few years ago after consuming more than $12.5 billion, but NASA is profiting from it now.

“This is a very refreshing program,” said Lowell Keel, Hyper-X project manager at Micro Craft, the company that will build the models in Ontario and at the company’s headquarters in Tullahoma, Tenn. “They have created a program that’s doable and affordable.”

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Keel said construction of the first Hyper-X model will begin in a few months, and three more planes are to follow. Boeing Co.’s advanced programs group in Seal Beach is working on the plane’s overall design and its flight control and thermal protection systems. The first Hyper-X is expected to arrive at Dryden in April, with its first flight scheduled for January 1999.

After that, Thad Sandford, vice president for research engineering and advanced programs at Boeing, expects the Hyper-X will evolve into an unmanned supersonic platform for communications, spy missions and military weapons. Fifteen years hence, larger versions of the Hyper-X could be used for high-speed cargo delivery, commercial travel and delivering satellites into orbit, he said.

“This will be a breakthrough technology that changes the way we think about flying vehicles,” Sandford said.

Karen Kaplan can be reached at karen.kaplan@latimes.com

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Less is More

Falling budgets have forced NASA to rework itself into an agency that conducts “faster-better-cheaper” missions. Dryden Flight Research Center has taken that message to heart by conducting research in cooperation with a host of private companies.

NASA Total Budget

1998*: $13.5 (in billions)

* requested; final decision has not yet been made.

Dryden Total Budget

1997: $154.2 (in millions)

Number of Dryden Missions

1997: 27