NASA X-38 TEAM FLIES LARGEST PARAFOIL PARACHUTE IN HISTORY
February 4, 2000
James Hartsfield
Johnson Space Center, Houston, TX
(281) 483-5111
Release: J00-9
NASA X-38 Team Flies Largest Parafoil
Parachute in History
A team developing a prototype International Space Station "lifeboat"
called the X-38 Crew Return Vehicle successfully flew the largest
parafoil parachute in history last week at the U.S. Army’s Yuma
Proving Ground, Arizona, as they released a parachute with an area
almost one and a half times as big as the wings of a Boeing 747 jumbo
jet.
The unmanned Jan. 19 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 X-38 may become the first new U.S.
human spacecraft to fly to and from space in more than 20 years. The
parafoil recently tested in Arizona has a span of 143 feet and a
total surface area of 7,500 square feet, making it the largest
parafoil in the world.
“I think this is a world's record for a parafoil and it is a
significant milestone and accomplishment for NASA," said John
Muratore, who is leading the X-38 Crew Return Vehicle Project. "It
puts us a major step closer toward our goal of providing the space
station with the most flexible crew return option. This parafoil has
the size and all the features to enable it to be used for returning
humans from space.”
For the test, an 18,000-pound pallet, simulating the actual X-38, was
dropped from the back of a C-130 aircraft at an altitude of 21,500
feet. A 28-foot diameter extraction parachute pulled the test
platform from the aircraft at an air speed of 130 miles per hour to
begin the flight test. Once out of the aircraft, a newly designed
80-foot diameter drogue parachute stabilized and slowed the platform
to a vertical airspeed of 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 eight miles per hour. -MORE- -2-
“This parafoil is so big there is no way that it can all deploy
at once,” said Brian Anderson, X-38 Project Manager.
“Because of its size, the dynamic forces on the
parachute’s structure are phenomenal.” 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. The parafoil was stitched together at Pioneer Aerospace's
facility in Columbia, MS. 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 strength and quality of this parafoil is a real testimony to the
skill and dedication of the men and women who built it,”
Muratore said.
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 using a
smaller 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 the
Johnson Space Center will be released in orbit by the Space Shuttle
to fly back to Earth.
The X-38's design is called a lifting body. Unlike the space shuttle,
it does not have any wings. All of the lift necessary to maneuver and
fly the X-38 comes from the lift generated by the flow of air over
the body of the spacecraft and its fins. Lifting body configurations
were studied extensively in the 1960s and 1970s as space entry
vehicles. These vehicles all had very high landing speeds that proved
difficult to control. The combination of the lifting body for the
high speed part of entry followed by the parafoil for the final
landing have proven to be a winner in the X-38 project. The
large-scale drops of the parafoil were supplemented with well over
300 subscale drops.
“The subscale drops gave us the opportunity to test and refine
techniques and gain the experience we needed for the large-scale
drops at a much lower cost,” said Jenny Stein, Project lead for
the X-38 parachute systems. The 7,500 square-foot 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. *** NOTE: NASA photographs 7663-17, 7664-15 and 7665-15 can be
downloaded from the internet to illustrate this release. They, along
with other X-38 photos, are available at
http://spaceflight.nasa.gov/gallery/images/station/crvx38/ndxpage1.html Video to accompany this release will air on NASA-TV’s Videofile at 11 a.m., 2 p.m., 5 p.m. and 8 p.m. CST today or can be obtained by contacting the Johnson Space Center Media Resource Center at (281) 483-4231. NASA-TV can be accessed through GE2, transponder 9C. The frequency is 3880 Mhz with an orbital position of 85 degrees West Longitude, with audio at 6.8 MHz.
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