Andrew Yee
March 14th 05, 07:13 AM
Public Affairs
U.S. Air Force Academy
March 1, 2005
Release #044
CADET RESEARCH HELPS NASA RETURN SHUTTLES TO SPACE
U.S. AIR FORCE ACADEMY, Colo. -- Cadet research is helping NASA shuttles
return to space.
The shuttle program has been land-locked since the Feb. 1, 2003, loss of
the Space Shuttle Columbia. This academic year, the Air Force Academy is
assisting NASA's Return to Flight program by utilizing the skills of
instructors and cadets, and putting a model of the space shuttle through
its paces in the wind tunnels of the Department of Aeronautics.
"Mainly we're looking at its stability characteristics -- both
longitudinal and lateral-directional -- and aerodynamic characteristics
such as lift, drag, and lift-to-drag ratio, which is a big indicator of
glide range," said Cadet 1st Class David Schmitt.
That research includes the impact of leading edge damage on the shuttle's
wings, added Cadet 2nd Class Matt Karmondy. "The objective was to see if
leading edge damage would adversely affect, lift, drag, and stability of
the shuttle after reentry. It turned out certain damage configurations did
raise some concern, and further investigation will be conducted to see if
the shuttle has the capability to overcome stability issues caused by wing
leading edge damage."
The research is being accomplished in the Academy's Aeronautics Research
Center. This 5,100 square meter facility houses world-class experimental
and computational facilities, including five wind tunnels. NASA provided a
1.67 percent scale aluminum polymer model of the shuttle, for use in the
Academy's subsonic wind tunnel. This tunnel simulates speeds of 50 to 600
feet per second.
Last semester's research started with a baseline evaluation of the shuttle
model. Once the baseline data was collected, several different leading
edges were fitted on to the model. These changes simulate damage at
different locations, allowing researchers to evaluate the resulting
changes in pitch, roll, yaw, stabilization and other aerodynamic
characteristics of a damaged shuttle.
This semester's efforts expand the research into the wing structure
itself, said Dr. Thomas Yechout, Aeronautics department professor and
research advisor for the project.
"NASA is in the process of having a new wing for our model fabricated,"
said Yechout. "It will also have a variety of damage configurations along
the left wing. It differs from the first model wing since it will include
a cavity inside the wings' leading edge, with pressure taps inside the
cavity at various locations to measure pressure loads in the vicinity of
the damaged structure changes."
According to The Columbia Accident Investigation Board, the loss of the
space shuttle was caused by a piece of insulating foam which separated
from the external tank at 81.7 seconds after launch, and struck the left
wing's leading edge. Upon re-entry, this breach allowed superheated air to
penetrate the leading edge insulation and progressively melt the aluminum
structure of the wing. This weakened the wing until the increasing
aerodynamic forces of reentry caused loss of control and failure of the
wing. The Columbia broke up at an altitude of 203,000 feet while traveling
at Mach 18, just 15 minutes prior to its scheduled landing at Kennedy
Space Center, Fla., killing all on board.
NASA is utilizing the research capabilities of several organizations as
part of its Return to Flight program, including the Air Force Academy's
Department of Aeronautics. The Academy's been involved with NASA research
for the past 8 years, dealing with several past, current and future
spacecraft.
The Return to Flight research is one of approximately 300 undergraduate
research projects currently underway at the Air Force Academy.
U.S. Air Force Academy
March 1, 2005
Release #044
CADET RESEARCH HELPS NASA RETURN SHUTTLES TO SPACE
U.S. AIR FORCE ACADEMY, Colo. -- Cadet research is helping NASA shuttles
return to space.
The shuttle program has been land-locked since the Feb. 1, 2003, loss of
the Space Shuttle Columbia. This academic year, the Air Force Academy is
assisting NASA's Return to Flight program by utilizing the skills of
instructors and cadets, and putting a model of the space shuttle through
its paces in the wind tunnels of the Department of Aeronautics.
"Mainly we're looking at its stability characteristics -- both
longitudinal and lateral-directional -- and aerodynamic characteristics
such as lift, drag, and lift-to-drag ratio, which is a big indicator of
glide range," said Cadet 1st Class David Schmitt.
That research includes the impact of leading edge damage on the shuttle's
wings, added Cadet 2nd Class Matt Karmondy. "The objective was to see if
leading edge damage would adversely affect, lift, drag, and stability of
the shuttle after reentry. It turned out certain damage configurations did
raise some concern, and further investigation will be conducted to see if
the shuttle has the capability to overcome stability issues caused by wing
leading edge damage."
The research is being accomplished in the Academy's Aeronautics Research
Center. This 5,100 square meter facility houses world-class experimental
and computational facilities, including five wind tunnels. NASA provided a
1.67 percent scale aluminum polymer model of the shuttle, for use in the
Academy's subsonic wind tunnel. This tunnel simulates speeds of 50 to 600
feet per second.
Last semester's research started with a baseline evaluation of the shuttle
model. Once the baseline data was collected, several different leading
edges were fitted on to the model. These changes simulate damage at
different locations, allowing researchers to evaluate the resulting
changes in pitch, roll, yaw, stabilization and other aerodynamic
characteristics of a damaged shuttle.
This semester's efforts expand the research into the wing structure
itself, said Dr. Thomas Yechout, Aeronautics department professor and
research advisor for the project.
"NASA is in the process of having a new wing for our model fabricated,"
said Yechout. "It will also have a variety of damage configurations along
the left wing. It differs from the first model wing since it will include
a cavity inside the wings' leading edge, with pressure taps inside the
cavity at various locations to measure pressure loads in the vicinity of
the damaged structure changes."
According to The Columbia Accident Investigation Board, the loss of the
space shuttle was caused by a piece of insulating foam which separated
from the external tank at 81.7 seconds after launch, and struck the left
wing's leading edge. Upon re-entry, this breach allowed superheated air to
penetrate the leading edge insulation and progressively melt the aluminum
structure of the wing. This weakened the wing until the increasing
aerodynamic forces of reentry caused loss of control and failure of the
wing. The Columbia broke up at an altitude of 203,000 feet while traveling
at Mach 18, just 15 minutes prior to its scheduled landing at Kennedy
Space Center, Fla., killing all on board.
NASA is utilizing the research capabilities of several organizations as
part of its Return to Flight program, including the Air Force Academy's
Department of Aeronautics. The Academy's been involved with NASA research
for the past 8 years, dealing with several past, current and future
spacecraft.
The Return to Flight research is one of approximately 300 undergraduate
research projects currently underway at the Air Force Academy.