On April 14, 1981, more than 300,000 aerospace aficionados
assembled on the barren east shore of Rogers Dry Lake at Edwards Air
Force Base to witness a first in aerospace history. Some seven miles
away, on the ramp at NASA’s Dryden Flight Research Center, another 20,000
distinguished visitors and NASA employees gathered to behold
the same event.

They were rewarded that sunny spring morning, as the
double-crack of a powerful sonic boom resounded across the desert,
heralding the coming conclusion of the first Space Shuttle orbital
mission. Moments later, astronauts John Young and Robert Crippen
guided the shuttle Columbia onto lakebed runway 23, proving beyond
shadow of doubt that a spacecraft could return to Earth safely with a
powerless but controlled airplane-style landing.

But NASA’s flight research outpost in Southern California’s high
desert had made numerous contributions to the Space Shuttle program
before that historic first landing, and has made many more since.
Even today, 20 years after that epochal event, the Dryden Flight
Research Center plays a significant though often overlooked role in
America’s space flight program. Dryden’s major past and present
contributions to the Space Shuttle program include:

  • 1960s: Development of space-rated control, environmental and
    navigation systems – The X-15 hypersonic rocket plane program
    contributed directly to the Space Shuttle program through its
    pioneering development of reaction control systems for attitude
    control in space, including transition from aerodynamic controls to
    reaction controls and back again. Other X-15 contributions to the
    Shuttle program included the first practical full-pressure suit for
    pilot protection in space, inertial flight data systems in a high
    dynamic pressure space environment, demonstration of a pilot’s
    ability to function in a weightless environment, and development of
    improved high-temperature seals and lubricants.

  • 1960s-1970s: Energy Management Techniques for Re-entry and Landing
    – The X-15 rocket plane and the lifting bodies flown at Dryden made a
    major contribution to the development of energy management and
    unpowered landing techniques for the Space Shuttles. The X-15 and the
    wingless lifting bodies demonstrated that it was feasible for an
    aerospace vehicle with a low lift-to-drag ratio to make a safe,
    controlled landing without power.

  • 1970s: The F-8 Digital Fly-By-Wire program – Another Dryden
    contribution to shuttle development was in the testing of the flight
    control computers later used on the shuttles. The IBM AP-101
    computers were flight-validated during the second phase of the F-8
    Digital Fly-By-Wire (DFBW) research program before they were used on
    the shuttles.

  • 1970s: Shuttle Carrier Aircraft — Once the decision had been made
    to eliminate jet engines for the shuttles’ approach and landing at
    Edwards, a means of ferrying the shuttles back to the launch site had
    to be devised. Dryden engineers proposed a variation of the
    tried-and-true “mothership” concept that had been used for lifting the X-1
    through X-15 and the lifting bodies to launch altitude; the modified Boeing747
    Shuttle Carrier Aircraft evolved from their recommendation.

  • 1970s: YF-12 High-Speed Research – During the high-speed,
    high-altitude flight research program conducted with the Lockheed
    YF-12, Dryden engineers developed a central airborne performance
    analyzer which monitored various aircraft systems, detected problems
    and provided that data to the pilot, as well as to engineers and
    maintenance personnel on the ground. The analyzer became the
    forerunner of vehicle health monitoring systems used on the space
    shuttles and a variety of today’s aircraft.

  • 1977: Shuttle Approach and Landing Tests — Dryden hosted and
    helped conduct the Approach and Landing Tests (ALT) of the prototype
    shuttle orbiter Enterprise at Edwards AFB in 1977. The ALT validated
    the concept of carrying the shuttle on the 747 Shuttle Carrier
    Aircraft during captive-carry flights and of landing the shuttle
    without power during five free flights.

  • 1977: Resolving Pilot-Induced Oscillation problem — On the final
    ALT flight, the pilot overcontrolled the Enterprise and it entered a
    dangerous pilot induced oscillation (PIO)-a frequent phenomenon with
    new digital fight control systems-just at touchdown on Edwards’ main
    concrete runway. Subsequent flights with the F-8 DFBW and other
    aircraft demonstrated that the problem with the shuttle flight
    control system lay in a time delay that stimulated pilots to
    over-control because their inputs to the flight control computer were
    taking too long to go into effect. With their experience with digital
    flight controls from the F-8 DFBW, Dryden engineers designed a PIO
    suppression filter that solved the problem and was incorporated into
    the shuttles’ flight control computers.

  • 1977-78, 1983-85: Booster Recovery System – Dryden’s NB-52B
    mothership made 31 test flights in a two-phase project to validate
    the performance and reliability of the shuttle’s solid rocket booster
    parachute recovery system. The parachutes are used to slow the
    descent of the solid rocket booster casings once they have completed
    their boost phase and separated from the shuttles’ external fuel

  • 1979-80: Structural Loads and Orbiter Handling Analysis – At
    Johnson Space Center’s request, Dryden engineers conducted an
    independent analysis of the shuttle design related to
    aerothermal-induced structural loads and handling qualities prior to
    its first space flight. Dryden’s analysis found the shuttle’s control
    system was capable of compensating for uncertainties in the shuttle’s
    flight characteristics, and verified the overall adequacy of the
    design to accomplish re-entry from orbit and a safe landing on

  • 1980s: Thermal Protection System Testing – Dryden research pilots
    flew 60 missions in Dryden’s F-104 and F-15 aircraft to test space
    shuttle thermal protection tiles under various aerodynamic load
    conditions. The tests led to several changes to improve techniques
    for bonding the tiles to the shuttles’ surfaces.

  • 1990: Shuttle Drag Parachute Tests – NASA Dryden’s venerable NB-52B
    was used to help develop the drag parachute deployment system now
    used during space shuttle landings. During a series of eight flight
    tests in 1990, the modified bomber validated the initiation,
    deployment, inflation and overall operation of the parachutes. The
    drag chutes are deployed from the shuttles moments after touchdown,
    reducing tire and brake wear and shortening the rollout distance on
    the runway.

  • 1993-1995: Shuttle Tire and Brake Tests — NASA Dryden modified a
    Convair 990 into a Landing Systems Research Aircraft in the mid-1990s
    to test the shuttles’ tires and braking systems on a variety of
    runway surfaces. These tests led to improvements in both the tires
    and brakes, an increasing in the allowable crosswind landing limits
    and resurfacing of the runway at the Kennedy Space Center’s Shuttle
    Landing Facility which reduced shuttle tire wear by half.

  • 1981-Today: Primary/Alternate Landing Site – Dryden and the Edwards
    complex was the primary space shuttle landing site for the first 12
    years of the program, and has served as the backup alternate landing
    site since then. Out of 102 shuttle missions completed to date, 47
    have landed at Edwards, 54 at the Kennedy Space Center, and one at
    the White Sands Missile Range in New Mexico. The most recent mission
    to land at Edwards was STS-98, which saw the shuttle Atlantis land
    here on Feb. 20, 2001.

  • 1981-Today: Shuttle Post-Flight Processing Capability — Dryden
    maintains a full complement of equipment to support Space Shuttle
    landing, recovery, post-flight processing and turnaround operations
    to prepare the shuttles for their ferry flights back to the Florida
    launch site when landings occur at Edwards AFB. One of NASA’s two
    modified Boeing 747 Shuttle Carrier Aircraft is maintained on-site
    for this purpose.