NASA’s X-40A, a prototype of a space-return vehicle,
successfully completed its seventh and final test flight,
gathering information and clearing the way for future flights
of its larger brother, the X-37.

The unpiloted X-40A, an 85-percent scale model of the X-37, 22
feet long and about 2,600 pounds, was released from an Army
helicopter above NASA’s Dryden Flight Research Center,
Edwards, CA. The series of two-minute descents provided
valuable information for development and testing of the full-
scale X-37 orbital and re-entry vehicle.

“Every X-40A free-flight test met or exceeded our
expectations,” said Susan Turner, X-37 program manager at
NASA’s Marshall Space Flight Center, Huntsville, AL. “The most
significant thing we learned is that our predictions for X-37
are right on target.”

The X-37 experimental space plane is designed to demonstrate
technologies in the orbital and reentry environments for next-
generation reusable launch vehicles that should increase both
safety and reliability, while reducing costs by tenfold.

Guidance, navigation and control systems of the smaller X-40A
are similar to those planned for the X-37. They were tested
through complex maneuvers such as pitch, roll and yaw
adjustments when the nose is raised, rotated and moved side to
side during flight. The vehicle was also released off-
centerline, not directly over the landing site, testing the
flight computer’s ability to maneuver the vehicle to a
straight approach towards the landing site.

The Boeing Company, NASA’s partner in X-37, made major
modifications to the X-40A, on loan from the U.S. Air Force,
which also participates in the X-37 program. The free-flight
tests were conducted by Dryden with the cooperation of Edwards
Air Force Base.

“We successfully performed seven flights, each time pushing
the limits,” added Turner. “These tests are helping us
identify our safety parameters for tests to be performed on
the X-37.”

On average, the X-40A free flights lasted approximately 75
seconds from release to landing, with the vehicle reaching
speeds of more than 300 miles per hour.

Unpowered flights of the X-37, when the vehicle will be
attached to NASA’s B-52 carrier aircraft then released to
glide to Earth, could begin as early as 2002, with orbital
missions beginning in 2004.

The X-37 government team is led by Marshall, the Air Force
Flight Test Center at Edwards Air Force Base in Edwards, CA,
and the Space and Missile Systems Center and the Air Force
Research Laboratory in Albuquerque, NM. The X-37 industry team
is led by Boeing, Seal Beach, CA.