X-38: Crew Return
Vehicle
X-38 Team Successfully
Flies Largest Parafoil Parachute in History
Released Feb. 4, 2000
The
X-38 program has been discontinued. The following article is for
historical use.
 | | The
X-38 prototype of the Crew Return Vehicle is suspended under
its giant 7,500-square-foot parafoil during its eighth free
flight on Dec. 13, 2001. |
A team developing a prototype
International Space Station "lifeboat" called the X-38 Crew Return
Vehicle successfully flew the largest parafoil parachute in history
in January at the U.S. Army's Yuma Proving Ground in Arizona as
they released a parachute with an area almost 1.5 times as big as
the wings of a Boeing 747 jumbo jet.
The unmanned Jan. 19, 20002,
parafoil test was part of the development of a re-entry system for
the X-38 spacecraft. With an innovative combination of old and new
technology and a streamlined development, the goal of the X-38 team
is to develop a new human spacecraft for a fraction of the cost
of any past program. Plans are to develop and build four operational
X-38-based International Space Station Crew Return Vehicles for
less than half of what it cost to manufacture a single space shuttle
orbiter.
The new parafoil tested
in Arizona has a span of 43.6 meters (143 feet) and a total surface
area of 696.8 square meters (7,500 square feet).
For the test, an 8,164.8-kilogram
(18,000-pound) pallet, simulating the actual X-38, was dropped from
the back of a C-130 aircraft at an altitude of 6,555 meters (21,500
feet). An 8.5-meter-diameter (28-foot-diameter) extraction parachute
pulled the test platform from the aircraft at an air speed of 209
kilometers (130 miles) per hour to begin the flight test. Once out
of the aircraft, a newly designed 24.4-meter-diameter (80-foot-diameter)
drogue parachute stabilized and slowed the platform to a vertical
airspeed of 99.8 kilometers (62 miles) per hour and enabled the
parafoil to begin a five-stage deployment process. During its 11-minute
long flight, the parafoil slowed the test pallet to a gentle vertical
landing speed of less than 12.9 kilometers (eight miles) per hour.
Looking like a giant air mattress, the world's largest parafoil
slowly deflates seconds after it carried the X-38 prototype to a
landing on Rogers Dry Lake adjacent to NASA's Dryden Flight Research
Center at Edwards, California, at the end of its first free flight,
Nov. 2, 2000.
The size of the parafoil
posed technical challenges for the X-38 team. One problem encountered
in past tests has been to ensure that the parachute opens evenly.
To solve this and make certain that the parachute opens symmetrically
and rapidly, the team developed a revolutionary self-sealing floor
vent system on the parafoil's underside. During the recent test,
the parafoil opened to its full size in only 30 seconds.
 | |
X-38
Crew Return Vehicle on lakebed after landing on second free
flight.
|
The parafoil was stitched
together at Pioneer Aerospace's facility in Columbia, Miss. Because
of its unprecedented size and strength, personnel at Pioneer nicknamed
the parafoil "Sampson." A unique ripstop nylon material, customized
stitching and other safety devices incorporated into the parafoil
make the parachute not only the world's largest but also among the
strongest.
The test was the 30th large-scale
flight test conducted to support development of the parafoil, although
this was the largest and most comprehensive test to date. In addition
to tests at Yuma, four large-scale atmospheric flight tests of prototype
X-38 vehicles have been completed at NASA's Dryden Flight Research
Center in California using a smaller 511-square-meter (5,500-square-foot)
parafoil. For those tests, increasingly complex X-38 vehicles have
been launched from a B-52 carrier aircraft at increasingly higher
altitudes. More such tests are planned during the next year and
a half, leading up to a space flight test of the X-38 in 2002, when
an unmanned vehicle now under construction at NASA's Johnson Space Center will be released in orbit by the space shuttle to fly back
to Earth.
The record-setting parafoil
will be tested at Yuma again this spring and will then be integrated
with one of the X-38 vehicles at Dryden for a test flight there
late this year.
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