Aerospace Technology Development

 

X-34 Vehicle Reaches Assembly Milestone

This is an artist concept of the X-34 Technology Testbed Demonstrator, the X-34 will demonstrate key vehicle and operational technologies applicable to future low-cost reusable launch vehicles.

NASA's first X-34 has completed its transformation from a structural test vehicle into a flying experimental rocket plane and is ready to begin tests that will lead to its maiden flight. The X-34 is a flying laboratory for technologies and operations applicable to future low-cost reusable launch vehicles. It is one of a family of technology demonstrators aimed at lowering launch costs from $10,000 to $1,000 per pound.

NASA decided in mid-1999 to upgrade the A-1 into a flight vehicle to augment two other flying X-34s—designated A-2 and A-3—now under construction at Orbital Sciences Corporation's Dulles, Virginia facility. With this upgrade comes a new designation. The nonflying X-34 A-1 will now become the A-1A. Assembly of the second (A-2) of NASA's three X-34 rocket research planes also reached a major milestone recently with the attachment of its composite wing to its fuselage at Orbital.

Orbital is building and will operate the three experimental robot planes under contract to NASA's Marshall Space Flight Center in Huntsville, Alabama. Orbital built the A-1 as a structural test article for ground vibration and captive flights while attached to its L-1011 carrier plane. Led by Marshall, a team of engineers and technicians from Orbital, NASA's Dryden Flight Research Center in Edwards, California, and NASA's Kennedy Space Center in Florida added flight computers, electronics, hydraulics, landing gear and other equipment to the A-1A—all needed to ready this first X-34 for unpowered flights at White Sands Missile Range in New Mexico.

"The A-1A is identical to the other flight vehicles except that it lacks the thermal protection system and propulsion system required for high-speed, high-altitude flight," said Jeff Sexton, flight-testing and operations project manager for Marshall's Pathfinder Program, which includes the X-34. “But we've added all the flight mechanisms—avionics and wiring, hydraulics, control surfaces, landing gear mechanism and flight softwareÐneeded for unpowered flight testing.”

The X-34's first tests, likely to have begun by press time, will not leave the ground. Instead, the vehicle will be towed behind a semi-truck for up to 10,000 feet along the desert lakebed at Edwards. Orbital plans to conduct 16 tests. The X-34 will be released at speeds up to 80 miles per hour as a way to prove the craft's guidance and navigation system, nose wheel steering, braking, rudder speed brake and rudder steering. The X-34 will be attached to the tow truck by a specially designed 500-foot rope with electrical connections to provide communications between the X-34 and ground test engineers. After successful ground testing, the A-1A will be attached to Orbital's L-1011 carrier plane, Stargazer, to finish the captive-carry flights required by the Federal Aviation Administration to verify that the combined aircraft are safe to fly.

Following those tests, the X-34 project transitions to White Sands Missile Range for unpowered flights of the A-1A. The L-1011 will carry it to an altitude of about 35,000 feet and release it to make an automated flight and landing at the White Sands Space Harbor. Five unpowered flights are planned using the A-1A. “These glide flights will give us an understanding of how the X-34 separates from the L-1011 and its flight characteristics,” Sexton said. “We will be able to test its control surface effectiveness, [and] validate the flight software that controls guidance, navigation, final approach, touchdown and landing rollout without risking the two fully functional powered flight vehicles.”

The suborbital X-34 is 58.3 feet (17.77 meters) long and 27.7 feet (8.44 meters) wide. It is capable of flying up to eight times the speed of sound and reaching altitudes of approximately 50 miles. It is scheduled to make a total of 27 unpowered and powered flights from government ranges in New Mexico, California and Florida.

The second vehicle, the A-2, is scheduled to make the X-34's first powered flights from Dryden at Edwards Air Force Base, California, this year. After the A-2 vehicle is assembled and tested at Orbital, the wing—manufactured by R-Cubed of West Jordan, Utah—will be removed and shipped to Dryden. The fuselage will be shipped to Holloman Air Force Base in New Mexico. There, integrated with its Fastrac rocket engine, it will undergo propulsion system testing before being shipped to Dryden, where the wing will be reattached for powered flights.

The Fastrac engine was designed and developed by Marshall, which is NASA's Lead Center for Space Transportation System Development. The first X-34 is now at Dryden being modified for unpowered flight testing at White Sands Missile Range. The third X-34, still in early stages of production, will be used to flight-test additional technologies late in the series of 27 planned X-34 missions.