Reusable Rocket : McDonnell Prototype Would Land Feet First

In science fiction, rockets that venture into space always return to Earth by descending upright with their engines spewing out fire, but the world’s rocket scientists never latched on to that notion.

Now McDonnell Douglas is completing a prototype of the first rocket that will land by a dramatic vertical descent--after which it can be refueled and used again.

The 40-foot-tall McDonnell rocket, sporting four liquid hydrogen engines, will be rolled out of its hangar Saturday morning at the firm’s space systems unit in Huntington Beach and will begin flight testing in a few months at the Army’s White Sands range in New Mexico.

McDonnell is hoping the technology will revolutionize space transportation, cutting launch costs to about a tenth of current tabs. Eventually, the firm believes, it could build a full-size rocket to reach orbit on a single stage and return intact.

Flights would cost $10 million and possibly as little as $1 million, thanks to fully reusable engines, fuel tanks and electronics that would require just eight hours of servicing between flights, the firm’s engineers proclaimed at a technical conference last year.

But critics abound, asserting that the ambitious project is making claims not unlike those made of the space shuttle program in the 1970s--which proved to be grossly inaccurate. A National Research Council report last year concluded that, while the goal of reaching orbit with a single-stage rocket might be met, better alternatives exist in the near term.

The issue comes at a critical juncture in the U.S. space program. The government has started and stopped a number of developments to update its aging launch system, even while European and Asian nations are closing the gap in space technology. The French Ariane rocket now handles more than 50% of all commercial launches.

“We have a serious problem with the space program, because it is old,” said Rep. George E. Brown Jr. (D-Colton), chairman of the House Space Science and Technology Committee. “All the facilities are aging and the bureaucracy that supports it is in need of some reconfiguration.”

Unlike past government boondoggles, the experimental McDonnell rocket, called the Delta Clipper, was built in 18 months for $60 million--on schedule and within budget. By contrast, the recently completed toilet for the space shuttle cost $23 million.

McDonnell adopted a management system modeled after the Lockheed Skunk Works to build a prototype quickly. The McDonnell prototype rocket was funded by the Pentagon’s Star Wars office, circumventing both NASA’s and the Air Force’s space bureaucracy.

Costs were held in check by using hand-me-downs--a guidance system from an F-15 jet fighter and some leftover fuel tanks from another program. Noted aircraft designer Burt Rutan of Mojave, Calif., made the rocket’s external composite shell, said Paul Klevatt, McDonnell’s chief engineer for the project.

McDonnell designed the rocket to be loaded, flown, serviced and refueled like an airplane. It dispatched a crew of aircraft engineers from its Douglas Aircraft unit to work with the rocket designers.

The firm also gave the program senior management attention, assigning moon-walking astronaut Pete Conrad, a company vice president, to an electronic-equipment trailer in Huntington Beach to help with work on launch procedures.

“I haven’t had this much fun in 25 years,” Conrad said.

The prototype rocket will be used only for suborbital testing. By the end of this year, it is supposed to ascend to a maximum altitude of 20,000 feet, arc ground-ward and then execute a difficult rotation maneuver at 16,000 feet for a vertical descent, according to Klevatt.

Future phases of the program will be far more demanding. McDonnell must persuade either the Air Force or NASA to fund the full-scale orbital rocket--at a cost of at least $2 billion.

No rocket has ever reached orbital speed of 17,000 m.p.h. on a single stage. In the past, rockets have used two or three stages, jettisoning empty tanks and spent engines along the trajectory to reduce weight. In a single-stage rocket, each extra pound of weight reduces the payload by an equal amount.

To make orbit on a single stage will require an extremely lightweight structure, in which the liquid hydrogen and oxygen fuel represents nearly 90% of the vehicle’s weight--the so-called mass fraction--according to McDonnell estimates. Also, the engines will require highly efficient fuel combustion--rivaling the space shuttle engines but operating at half the internal pressures.

The eventual full-scale orbital rocket envisioned by McDonnell would be 130 feet tall and 40 feet wide with eight engines, allowing the ship to reach orbit in an emergency with one engine off. It would loft 20,000 pounds into low Earth orbit.

Artur Mager, a recognized aerospace expert, examined the Delta Clipper proposal for the National Research Council last year and concluded that with innovative new materials--such as lithium aluminum alloys and new forms of graphite epoxy--the company could achieve its advertised performance.

Nonetheless, the research council recommended that McDonnell needed a better understanding of the new materials and the adequacy of heat protection systems. The report concluded that the single-stage-to-orbit technology would not be ready in the next decade and that attention should instead be focused on a new expendable launch vehicle.

“I have spoken to McDonnell people many times and they claim they have all the technology they need, but I sort of doubt it,” Mager said.

Still, he gives the McDonnell rocket a far better chance of success than the National Aero Space Plane, the government’s $12-billion effort at Rockwell International to build a plane capable of flying into orbit using supersonic ramjet engines. That program was recently scaled back amid cost and technical concerns.

Other rocket experts take an even tougher view. Eberhardt Rechtin, a USC professor and former Aerospace Corp. president, said single-stage rockets have been studied since the 1960s.

The McDonnell project “defies the best principles of launching payload into space and it would be astonishing if it pays off,” he said. Rechtin also criticized the Strategic Defense Initiative Organization’s sponsorship of the program, because it has nothing to do with the agency’s mission.

Rocco Petrone, a retired rocket scientist who was launch director of the Apollo moon project, expressed concerns about the fuel efficiency of a rocket-powered landing and the problem of storing liquid hydrogen during the heat of re-entry into Earth’s atmosphere.

“It may look good on paper, but making the hardware work is another story,” he said.

Conrad said he has heard all the criticism before and brushes it aside, saying McDonnell has solved the major problems using existing technology.

“If people wonder why we can’t fly into space, it’s because it costs too much,” Conrad said. “This is designed to do for space flight what the DC-3 did for aviation.”