NASA’s successful test flight of X-40A vehicle is major accomplishment for its X-37 program

The X-40A glided to the runway at Edwards Air Force Base in
California, its nose wheel set down smoothly, and the test vehicle rolled to
a gentle stop, but no pilot exited the craft, for there was no pilot. The
X-40A flew itself, guided by its on-board systems.

“It was truly a beautiful sight, and cause for celebration,” said
Susan Turner, NASA’s X-37 program manager at Marshall Space Flight Center in
Huntsville, Ala.

The X-40A’s free flight and landing was conducted as part of the
X-37 program, intended to reduce the risk of flight testing the X-37, not
from 15,000 feet (about 4.6 kilometers) like the X-40A, but from low Earth
orbit. The X-37 is an experimental re-entry vehicle that will enable NASA to
test advanced technologies in the harsh environment of space and in
returning through Earth’s atmosphere.

This first successful test of the X-40A by NASA was a big step
forward for the X-37 program. Its primary objective was to validate the
vehicle’s Computed Air Data Systems (CADS), which also will be used in the
flight control system of the X-37.

“Our initial review of the test shows the vehicle’s performance
matched our predictions nearly perfectly,” said Turner.

This flight also demonstrated the kind of teamwork that will be
needed for NASA to develop a second generation reusable launch vehicle
capable of replacing today’s Space Shuttle. The Boeing Company, NASA’s
partner in X-37, made major modifications to the X-40A, which was on loan
from the U.S. Air Force, which also participates in the X-37 program. The
test was conducted by NASA’s Dryden Flight Research Center, Edwards, Calif.,
with the cooperation of Edwards Air Force Base. And the X-37 was lifted
into the sky and released by a U.S. Army Chinook helicopter provided by Fort
Rucker, Alabama.

The X-37 program consists of three phases of flight testing: the
X-40A free flight series is phase one; phase two begins with X-37 unpowered
flights; and phase three will be the orbital test flights.

“Incremental testing is a cost-effective approach to designing an
experimental spacecraft,” said Turner. “By leveraging an existing asset –
the X-40A – we obtain valuable information which enhances the likelihood of
mission success for the X-37.

“Upcoming free flights will push the envelope further. Each time,
we’ll change some of the test variables of the X-40A to check the vehicle’s
controllability and maneuverability in a different flight situation. The
results will help us determine our safety parameters when we fly the X-37.”

A second free flight test of the X-40A is scheduled for early April.
The objectives are the same as the first flight, however, engineers will
modify control variables to see how the vehicle responds.

The X-40A test vehicle was built in 1998 for the Air Force by The
Boeing Company at its Seal Beach, Calif., facility. It has a fuselage length
of 22 feet (about 6.7 meters), a wing span of 12 feet (about 3.65 meters)
and weighs about 2,600 pounds (about 1179 kilograms). It is an 85 percent
scale version of the X-37.

The X-37 government team, led by the Marshall Center, includes
NASA’s Ames Research Center in Mountain View, Calif.; Johnson Space Flight
Center in Houston, Texas; Kennedy Space Center at Cape Canaveral, Fla.;
Goddard Space Flight Center in Greenbelt, Md.; Langley Research Center in
Hampton, Va.; Dryden Flight Research Center and the Air Force Flight Test
Center, both at Edwards Air Force Base in Edwards, Calif.; and the Space and
Missile Systems Center and the Air Force Research Laboratory in Albuquerque,
N.M. The X-37 industry team is led by Boeing at Seal Beach, Calif.