For release: June 14, 1996
Headquarters, Washington, D.C.
Ann C. Gaudreaux
Langley Research Center, Hampton, Va.
RELEASE NO. 96-045
WING-BOX SUCCESSFULLY TESTED FOR RLV PROGRAM
A full-scale segment of a graphite-composite wing designed for a
reusable launch vehicle (RLV)
was successfully "tested to failure" to determine the maximum load
that the wing-box would carry and its mode of failure
Tested at NASA's Langley Research Center, Hampton, Va., the wing
broke at twice the design load limit. "Load" is defined as the
forces that a component of the vehicle experiences during take-off,
landing, and conducting various maneuvers. Design limit load is the
maximum load that a component is expected to experience one time
during the life of the vehicle. Knowing at what load and how a
structural component fails is essential to being able to design a
vehicle that will be safe at all expected flight conditions.
This is the first structural test of a full-scale component
designed and fabricated to validate the use of graphite-composite
primary structure for the RLV. The test results validated the
design, analysis and fabrication procedure with excellent agreement
obtained between the predicted results and the experimental
The wing-box test component, six feet wide by 10 feet long by
three-and-one-half feet deep, was designed and fabricated by a
Rockwell International/Northrop-Grumman industry team using a
high-temperature graphite bismaleimide composite material. The use
of graphite-composites for the primary structure, like the wings,
the thrust structure which connects the engines to the vehicle and
the intertank which connects the fuel tanks of the RLV together, is
essential for a cost-effective launch system that can also meet the
weight requirements for a single-stage-to-orbit vehicle.
Reusable launch vehicles are being tested by NASA as future
spacecraft that can be used in the commercial market as well as for
scientific research. It is hoped that RLVs of the future will be
designed to lower the costs of research and manufacturing in
Structural health monitoring sensors were also installed on the
test component to verify their use for the RLV. A health monitoring
system is one that monitors and records wing-box deflections,
strain, temperature, etc. An effective health monitoring system
would reduce the need for physical inspections of certain critical
components such as the wings or the fuel tanks, and could
significantly reduce operation costs and improve launch
reliability. Langley responded to requests by its industry
partners, Rockwell International/Northrup-Grumman, to accelerate
the tests by four months, advancing the time of testing from 11
months to seven months. Langley researchers at the Hampton, Va.
Center successfully conducted the above tests ahead of schedule so
that the industry partners could include the results in their
reusable launch vehicle Phase II, X-33 proposal.
Three companies are presently bidding on Phase II of NASA's RLV
program. NASA will announce the winner of the RLV Phase II
competition by July 1.
Photos, b-roll and interviews are available. For more
information, please contact Ann Gaudreaux at 864-8150.
text-only version of this release