The first of three hypersonic (X-43A) research vehicles started the
final preparations toward a flight in early summer, as the second
vehicle arrived on January 31, 2001, at NASA’s Dryden Flight Research
Center, Edwards, Calif.

After successful completion of electrical and mechanical checks, mating
of the X-43A to the Pegasus( rocket booster was accomplished on January
10, 2001. Pegasus( is built by Orbital Sciences Corp, Dulles, Va. The
Orbital and Dryden team members performed several mission simulations
to validate the Hyper-X vehicle system operations.

“The Project team is excited about this milestone. Everyone is anxious
to fly,” said Joel Sitz, Dryden X-43 project manager. “We have worked
extremely hard on improving the chances for Hyper-X mission success.
All the organizations at Dryden were involved and very helpful.

Sitz added that, “the X-43A flight project engages the best of what
flight research stands for and the upcoming first flight of an
integrated-airframe scramjet is an aerospace milestone all of us can be
proud of.”

The Hyper-X program is aimed at flight-validating airframe-integrated,
air-breathing propulsion system designs, which so far have only been
tested in ground facilities, such as wind tunnels. A major goal of the
program is the demonstration of a scramjet engine.

A ramjet operates by subsonic combustion of fuel in a stream of air
compressed by the forward speed of the aircraft itself, as opposed to a
jet engine where fan blades compress the air. The scramjet is a ramjet
engine in which the airflow through the whole engine remains
supersonic. The fuel for the X-43A is hydrogen.

Unlike a rocket that must carry its own oxygen for combustion, an
air-breathing aircraft scoops air from the atmosphere. An air-breathing
vehicle can carry more payload than a rocket-powered propulsion
vehicle. The X-43 will use the body of the aircraft to form critical
elements of the engine with the forebody acting as the intake for the
airflow and using the aft section as the nozzle.

The X-43A is a 12-foot, unpiloted research vehicle manufactured by
MicroCraft Inc., Tullahoma, Tenn. A captive-carry flight, where the
B-52 and X-43A “stack” remain mated to test flight systems and practice
procedures, will precede a free flight set for early summer. The
booster accelerates until the X-43A separates at a predetermined
altitude and velocity to fly a pre-programmed trajectory. Three
research flights are planned–two flights at Mach 7 and one at Mach 10.
The X-43A will conduct aerodynamic and propulsion experiments until it
impacts into the Pacific Ocean.

NASA Langley Research Center, Hampton, Va., has overall management of
the program and leads the technology effort. Dryden is the lead for
the flight tests. Dryden engineers are working closely with their
colleagues from Langley and industry.


Still photos are available from the Dryden Public Affairs Office to
support this release. Check for availability of video. For photo
prints or video dubs, please call (661) 276-3449. Photos are also
available on the Internet under NASA Dryden Flight Research Center
Aircraft Photo Gallery, URL: