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-40A 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.