Andrew Yee
July 13th 05, 03:05 AM
United States Air Force
Air Force Materiel Command
Directorate of Public Affairs
Arnold Engineering Development Center
Arnold AFB, Tennessee
NEWS RELEASE: July 7, 2005
Writer: Compiled by Janae' Daniels
Release: 2005-216
Tennessee playing a role in shuttle Return to Flight
ARNOLD AIR FORCE BASE, TENN -- The United States Air Force's Arnold
Engineering Development Center (AEDC), located at Arnold Air Force Base in
Tennessee, played an important role in supporting NASA's Space Shuttle
Return to Flight program will culminate with the launch of Space Shuttle
Discovery as early as July 13.
Following the break up of Columbia during re-entry in February 2003, AEDC
facilities and personnel experienced in manned space program testing
responded to help NASA return to manned space flight. Return to Flight
tests were conducted in five of AEDC's 58 testing facilities.
Here is a synopsis of the tests conducted at AEDC.
Wind Tunnel Testing
The first of three series of wind tunnel tests occurred in June 2003 in
AEDC's Tunnel A. These tests demonstrated the aerodynamic capabilities of
some of the Space Shuttle redesign initiatives and provided valuable data
on the aerodynamic heating caused by the new design during ascent.
Mounting an AEDC-designed and fabricated 100-percent scale metal model of
the bipod ramp that connects the space shuttle to the main external fuel
tank near the shuttle's nose in the tunnel, test personnel generated an
environment similar to that encountered at various launches to orbit to
observe the aerodynamic flow conditions.
The second series of tests began in the center's 4-foot transonic wind
tunnel in August 2003. There, test crews measured the air pressure on
models of the same bipod, ramp and a redesigned bipod area by placing
pressure sensors in the models.
Embedded heaters on the insulation foam models prevented ice formation on
the exposed metal components during tests and allowed the predicted flight
structural thermal profile to be very accurately simulated.
AEDC fabricated a new wind tunnel side wall that integrated model features
with the test facility to more closely match the flight airflow conditions
in the bipod area.
Another series of tests were conducted in the center's hypersonic Tunnel
C. During this series, an AEDC-designed and fabricated 30-percent scale
redesigned bipod model was used to collect the heating rates and pressure
measurements from locations distributed around the redesigned bipod
attachment fitting and surrounding insulation foam.
Foam Impact Testing
Engineers and test operators in AEDC's S-3 Ballistic Impact Range launched
hundreds of block-shaped projectiles made of the insulating foam material
used on the shuttle's external tank. These "shots" simulated pieces of
external tank foam breaking away from the tank during flight, as happened
to Columbia, and striking various parts of the space shuttle such as the
solid rocket booster (SRB).
Test operators launched the blocks at various velocities and angles to
simulate the different ways in which foam might strike the SRBs. These
tests helped determine the effects of foam impact and provided information
on the rocket booster's ability to withstand those impacts.
During each shot, high-pressure helium gas launched the foam projectiles
at speeds from 150 to 2,255 feet per second down a 86-foot-long
rectangular barrel.
The targets included the struts connecting the solid rocket booster and
external fuel tank, core panels representative of the thermal protection
system materials and cover material for the range safety system antennae
that would be used to abort a mission if sufficient damage occurred to the
shuttle.
High-speed video cameras operating at speeds up to 20,000 frames per
second documented the impacts and provided a means for measuring the
velocity of the projectiles. In instrumentation on the target's panels
acquired data at 50,000 samples per second to provide information on the
stresses the targets sustained during the impact.
"Full stack" testing
AEDC completed a week of testing on a three-percent scale "full stack"
model in the center's 16-foot transonic wind tunnel in October 2004. The
"full stack" model represents a space shuttle configuration similar to the
vehicle at launch, with the external fuel tanks attached.
The objective of the test was to perform detailed pressure and force
measurements, and flow visualization on the shuttle model, particularly in
the bipod area. The model was subjected to speeds ranging from those
encountered just after takeoff to Mach 1.5.
Pressure sensitive paint flow visualization was used to determine pressure
data over the entire surface of the shuttle model as it was tested. This
specialized paint fluoresces or glows under certain lighting, with
brighter areas indicating lower pressure and dimmer areas indicating
higher pressure. The paint is applied to the model, which is then imaged
with digital cameras while the wind tunnel is operating. The images are
processed through a program in a supercomputer to show the varying
pressures in different colors. The team acquired pressure data on the two
versions of external tanks including the newer super lightweight tank and
the older standard weight tank that dates to the late 1970s, to compare
aerodynamic performance.
During the force phase of the test, parts of the liquid oxygen fuel system
were installed onto small balances. Forces on these components were
measured over a range of simulated flight conditions and model attitudes,
including the roll maneuver that occurs shortly after take-off. NASA used
the AEDC PSP flow visualization data to validate the computational fluid
dynamics data it generated in testing at NASA facilities.
The people of AEDC are proud of the important role they played in
returning the shuttle to flight.
AEDC has a long history of supporting the nation's manned space programs.
AEDC played a key role in the development of projects Mercury, Gemini and
Apollo. The center also provided critical testing to the development of
the space shuttle.
Editorial Note:
Arnold Engineering Development Center is the nation's largest complex of
flight simulation test facilities. The center was dedicated in June 1951
by President Harry Truman and named after 5-star General of the Air Force
Henry 'Hap' Arnold, visionary leader of the Army Air Forces in World War
II and the only Airman to hold 5-star rank. Today, this $7.8 billion
complex has 58 aerospace test facilities located at Arnold Air Force Base,
Tenn., and the center's remote operating location Hypervelocity Tunnel 9
in White Oak, Md. The test facilities simulate flight from subsonic to
hypersonic speeds at altitudes from sea level to space. Every high
performance flight system in use by the Department of Defense today and
all NASA manned spacecraft have been tested in AEDC's facilities. Today
the center is testing the next generation of aircraft and space systems.
For more information on AEDC visit the center's Web site at
http://www.arnold.af.mil
IMAGE CAPTIONS:
[Image 1:
http://www.arnold.af.mil/aedc/returntoflight/d0408565.jpg (739KB)]
Machinist Larry Phipps at the Air Force's Arnold Engineering Development
Center loads a foam projectile into an 86-foot-long rectangular barrel
used to conduct impact testing for the Space Shuttle Return to Flight
program. (AEDC photo)
[Image 2:
http://www.arnold.af.mil/aedc/returntoflight/d0507010.jpg (366KB)]
Pressure sensitive paint flow visualization data from a threepercent model
of the space shuttle tested at the Air Force's Arnold Engineering
Development Center's long transonic wind tunnel was used to validate
computational fluid dynamics data generated by NASA. (AEDC photo)
[Image 3:
http://www.arnold.af.mil/aedc/returntoflight/d0410516.jpg (1.9MB)]
A "blue light" photo of the "full stack" space shuttle model in 16-foot
transonic wind tunnel at the Air Force's Arnold Engineering Development
Center. (AEDC photo)
[Image 4:
http://www.arnold.af.mil/aedc/returntoflight/d0410474.jpg (529KB)]
Jim Greathouse, computational fluid dynamics (CFD) analyst, left to right,
Darby Vicker, CFD analyst, and Bob Ess, program manager, all from NASA
Johnson Space Center, examine the shuttle model during a model change at
in the16-foot transonic wind tunnel at the Air Force's Arnold Engineering
Development Center. (AEDC photo)
[Image 5:
http://www.arnold.af.mil/aedc/returntoflight/d0507020.tif (160KB)]
Still photo of a space shuttle block foam impact test on the shuttle's
bipod area at speeds up to 2,255 feet per second was performed at the Air
Force's Arnold Engineering Development Center's Ballistic Impact Range
S-3. (AEDC photo)
Air Force Materiel Command
Directorate of Public Affairs
Arnold Engineering Development Center
Arnold AFB, Tennessee
NEWS RELEASE: July 7, 2005
Writer: Compiled by Janae' Daniels
Release: 2005-216
Tennessee playing a role in shuttle Return to Flight
ARNOLD AIR FORCE BASE, TENN -- The United States Air Force's Arnold
Engineering Development Center (AEDC), located at Arnold Air Force Base in
Tennessee, played an important role in supporting NASA's Space Shuttle
Return to Flight program will culminate with the launch of Space Shuttle
Discovery as early as July 13.
Following the break up of Columbia during re-entry in February 2003, AEDC
facilities and personnel experienced in manned space program testing
responded to help NASA return to manned space flight. Return to Flight
tests were conducted in five of AEDC's 58 testing facilities.
Here is a synopsis of the tests conducted at AEDC.
Wind Tunnel Testing
The first of three series of wind tunnel tests occurred in June 2003 in
AEDC's Tunnel A. These tests demonstrated the aerodynamic capabilities of
some of the Space Shuttle redesign initiatives and provided valuable data
on the aerodynamic heating caused by the new design during ascent.
Mounting an AEDC-designed and fabricated 100-percent scale metal model of
the bipod ramp that connects the space shuttle to the main external fuel
tank near the shuttle's nose in the tunnel, test personnel generated an
environment similar to that encountered at various launches to orbit to
observe the aerodynamic flow conditions.
The second series of tests began in the center's 4-foot transonic wind
tunnel in August 2003. There, test crews measured the air pressure on
models of the same bipod, ramp and a redesigned bipod area by placing
pressure sensors in the models.
Embedded heaters on the insulation foam models prevented ice formation on
the exposed metal components during tests and allowed the predicted flight
structural thermal profile to be very accurately simulated.
AEDC fabricated a new wind tunnel side wall that integrated model features
with the test facility to more closely match the flight airflow conditions
in the bipod area.
Another series of tests were conducted in the center's hypersonic Tunnel
C. During this series, an AEDC-designed and fabricated 30-percent scale
redesigned bipod model was used to collect the heating rates and pressure
measurements from locations distributed around the redesigned bipod
attachment fitting and surrounding insulation foam.
Foam Impact Testing
Engineers and test operators in AEDC's S-3 Ballistic Impact Range launched
hundreds of block-shaped projectiles made of the insulating foam material
used on the shuttle's external tank. These "shots" simulated pieces of
external tank foam breaking away from the tank during flight, as happened
to Columbia, and striking various parts of the space shuttle such as the
solid rocket booster (SRB).
Test operators launched the blocks at various velocities and angles to
simulate the different ways in which foam might strike the SRBs. These
tests helped determine the effects of foam impact and provided information
on the rocket booster's ability to withstand those impacts.
During each shot, high-pressure helium gas launched the foam projectiles
at speeds from 150 to 2,255 feet per second down a 86-foot-long
rectangular barrel.
The targets included the struts connecting the solid rocket booster and
external fuel tank, core panels representative of the thermal protection
system materials and cover material for the range safety system antennae
that would be used to abort a mission if sufficient damage occurred to the
shuttle.
High-speed video cameras operating at speeds up to 20,000 frames per
second documented the impacts and provided a means for measuring the
velocity of the projectiles. In instrumentation on the target's panels
acquired data at 50,000 samples per second to provide information on the
stresses the targets sustained during the impact.
"Full stack" testing
AEDC completed a week of testing on a three-percent scale "full stack"
model in the center's 16-foot transonic wind tunnel in October 2004. The
"full stack" model represents a space shuttle configuration similar to the
vehicle at launch, with the external fuel tanks attached.
The objective of the test was to perform detailed pressure and force
measurements, and flow visualization on the shuttle model, particularly in
the bipod area. The model was subjected to speeds ranging from those
encountered just after takeoff to Mach 1.5.
Pressure sensitive paint flow visualization was used to determine pressure
data over the entire surface of the shuttle model as it was tested. This
specialized paint fluoresces or glows under certain lighting, with
brighter areas indicating lower pressure and dimmer areas indicating
higher pressure. The paint is applied to the model, which is then imaged
with digital cameras while the wind tunnel is operating. The images are
processed through a program in a supercomputer to show the varying
pressures in different colors. The team acquired pressure data on the two
versions of external tanks including the newer super lightweight tank and
the older standard weight tank that dates to the late 1970s, to compare
aerodynamic performance.
During the force phase of the test, parts of the liquid oxygen fuel system
were installed onto small balances. Forces on these components were
measured over a range of simulated flight conditions and model attitudes,
including the roll maneuver that occurs shortly after take-off. NASA used
the AEDC PSP flow visualization data to validate the computational fluid
dynamics data it generated in testing at NASA facilities.
The people of AEDC are proud of the important role they played in
returning the shuttle to flight.
AEDC has a long history of supporting the nation's manned space programs.
AEDC played a key role in the development of projects Mercury, Gemini and
Apollo. The center also provided critical testing to the development of
the space shuttle.
Editorial Note:
Arnold Engineering Development Center is the nation's largest complex of
flight simulation test facilities. The center was dedicated in June 1951
by President Harry Truman and named after 5-star General of the Air Force
Henry 'Hap' Arnold, visionary leader of the Army Air Forces in World War
II and the only Airman to hold 5-star rank. Today, this $7.8 billion
complex has 58 aerospace test facilities located at Arnold Air Force Base,
Tenn., and the center's remote operating location Hypervelocity Tunnel 9
in White Oak, Md. The test facilities simulate flight from subsonic to
hypersonic speeds at altitudes from sea level to space. Every high
performance flight system in use by the Department of Defense today and
all NASA manned spacecraft have been tested in AEDC's facilities. Today
the center is testing the next generation of aircraft and space systems.
For more information on AEDC visit the center's Web site at
http://www.arnold.af.mil
IMAGE CAPTIONS:
[Image 1:
http://www.arnold.af.mil/aedc/returntoflight/d0408565.jpg (739KB)]
Machinist Larry Phipps at the Air Force's Arnold Engineering Development
Center loads a foam projectile into an 86-foot-long rectangular barrel
used to conduct impact testing for the Space Shuttle Return to Flight
program. (AEDC photo)
[Image 2:
http://www.arnold.af.mil/aedc/returntoflight/d0507010.jpg (366KB)]
Pressure sensitive paint flow visualization data from a threepercent model
of the space shuttle tested at the Air Force's Arnold Engineering
Development Center's long transonic wind tunnel was used to validate
computational fluid dynamics data generated by NASA. (AEDC photo)
[Image 3:
http://www.arnold.af.mil/aedc/returntoflight/d0410516.jpg (1.9MB)]
A "blue light" photo of the "full stack" space shuttle model in 16-foot
transonic wind tunnel at the Air Force's Arnold Engineering Development
Center. (AEDC photo)
[Image 4:
http://www.arnold.af.mil/aedc/returntoflight/d0410474.jpg (529KB)]
Jim Greathouse, computational fluid dynamics (CFD) analyst, left to right,
Darby Vicker, CFD analyst, and Bob Ess, program manager, all from NASA
Johnson Space Center, examine the shuttle model during a model change at
in the16-foot transonic wind tunnel at the Air Force's Arnold Engineering
Development Center. (AEDC photo)
[Image 5:
http://www.arnold.af.mil/aedc/returntoflight/d0507020.tif (160KB)]
Still photo of a space shuttle block foam impact test on the shuttle's
bipod area at speeds up to 2,255 feet per second was performed at the Air
Force's Arnold Engineering Development Center's Ballistic Impact Range
S-3. (AEDC photo)