A Year of Significant Milestones at NASA Dryden

As 2004 drew to a close, NASA’s Dryden Flight Research Center at
Edwards Air Force Base looked back on a year of challenge and
accomplishment in its role of NASA’s lead center for atmospheric
flight research. A few of the highlights included:

X-43A / Hyper-X — On March 27, four decades of supersonic-combustion
ramjet propulsion research culminated in a successful flight of the
X-43A hypersonic technology demonstrator, the first time a
scramjet-powered aircraft had flown freely. After being launched by
Dryden’s venerable B-52B mothership off the coast of Southern
California, a modified first-stage Pegasus booster rocketed the X-43A
to 95,000 feet before the X-43A separated and flew under its own
scramjet power at an airspeed of Mach 6.8, or about 5,000 mph, for
about 11 seconds. On Nov. 16, another identical scramjet-powered
X-43A did it again, this time reaching hypersonic speeds above Mach
9.6, or about 6,800 mph, in the final flight of the X-43A project.
Both flights set world airspeed records for an aircraft powered by an
air-breathing engine, and proved that scramjet propulsion is a viable
technology for powering future space-access vehicles and hypersonic
aircraft.

Access 5 — In May, Access 5, the joint government-industry program to
enable use of the national airspace by remotely operated unmanned
aircraft was kicked off. Primarily funded by NASA through the
High-Altitude, Long-Endurance Remotely Operated Aircraft in the
National Airspace project within the Vehicle Systems Program, Access
5 brings NASA, the Federal Aviation Administration, the Department of
Defense and six major industry members together to plan the safe,
orderly and efficient integration of unmanned aircraft into civil
airspace over the next five years. The focus is not only on
development of procedures and standards, but also on technologies
such as command and control, detection and avoidance.

Airborne Science — Advanced technology was used to improve our
understanding of biological and cultural resources and their
sustainable development. The Central and South America AirSAR 2004
mission used an Airborne Synthetic Aperture Radar aboard NASA’s DC-8
flying laboratory. The mission took place during the several weeks in
March over Costa Rica, Chile, Patagonia and the Antarctic Peninsula.
Other major Earth science missions during the year involving the
converted jetliner included the INTEX global air pollution surveys
and an AirSAR mission that captured 3-D images of seven active
Alaskan volcanoes to evaluate volcanic hazards and to improve the
understanding of the eruption process and frequency. NASA Dryden’s
ER-2 high-altitude science aircraft also was kept busy during 2004 on
a variety of atmospheric sampling and imaging missions.

Active Aeroelastic Wing — After a lengthy hiatus, Dryden’s Active
Aeroelastic Wing F/A-18 returned to the skies in mid-December to
begin its second phase of research flights. Following completion of
the first phase that evaluated the flight characteristics of a more
flexible wing, NASA Dryden and Boeing Phantom Works engineers
developed control laws over the past 18 months to enable active
control of wing flexibility for primary maneuvering control. About 35
flights at both subsonic and supersonic speeds are planned in Phase
II of the AAW project before it concludes next spring. Initial data
from the first four research flights indicate that AAW control law
roll rates were higher than predicted. Active Aeroelastic Wing
employs conventional control surfaces such as ailerons and
leading-edge flaps to aerodynamically induce twist. From flight test
and simulation data, the program will develop structural modeling
techniques and tools to help design lighter, more flexible high
aspect-ratio wings for future high-performance aircraft, which could
enable more economical operation or greater payload capability.

B-52B “Mothership” Retirement — After almost 50 years of serving as a
test and research aircraft, NASA’s venerable Boeing B-52B air-launch
“mothership” was retired from service on December 17. With no future
programs needing its capability envisioned in the foreseeable future
and maintainability becoming increasingly difficult for the
one-of-a-kind aircraft, the decision was made to retire the
eight-engine converted bomber to a place of honor on display at the
Edwards Air Force Base north gate. First flown in June 1955, the
B-52B air-launched a variety of exotic research aircraft ranging from
the X-15 rocket plane of the 1960s to the X-43A scramjet of 2004
during its storied career.

In 2005, NASA Dryden will be supporting both the Vision for Space
Exploration and Space Shuttle Return-to-Flight with several
engineering and flight research tasks.

Exploration Systems — NASA’s Exploration Systems Mission Directorate
selected Dryden to participate in two research and technology
development activities. Dryden has been tasked with leading the Aero
Assisted Mars Transfer Vehicle Study, with other NASA centers and
universities supporting the effort. For the second, the Ceramic Aft
Heat Shield Hot Structures Test, Dryden would provide the necessary
thermal and load testing of a candidate aft heat shield design for
the planned Crew Exploration Vehicle. Additionally, the directorate
has tasked Dryden to provide increased support to a number of
engineering disciplines that support the overall exploration vision
via integrated product and design teams.

Space Shuttle Return to Flight — NASA Dryden will support Space
Shuttle Return-to-Flight engineering efforts with a series of flights
by the center’s F-15B Research Testbed aircraft in early 2005. The
flights will obtain data on the shuttle’s external fuel tank
insulating foam debris or “divot” trajectories for computer code
validation. Among several objectives, the flights will help engineers
quantify divot trajectories using high-speed videography and provide
flight verification of debris tracking systems to be used for the
next shuttle launch.

(Editors who want to pursue story topics may call Dryden public
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