baalke@mars.jpl.nasa.gov (Ron Baalke) (01/19/90)
RELEASE: 90-8
RESEARCH EXPERIMENTS TO MONITOR COLUMBIA RE-ENTRY
During Columbia's fiery re-entry through Earth's atmosphere
at mission end, two experiments will measure the orbiter's
aerodynamic and thermodynamic characteristics to acquire data for
future space transportation systems.
STS-32 is the third flight of the Shuttle Infrared Leeside
Temperature Sensing (SILTS) and the Shuttle Entry Air Data System
(SEADS) experiments, developed by Langley Research Center,
Hampton, Va., in NASA's Orbiter Experiments (OEX) program.
The OEX program conducts atmospheric entry research during
the Shuttle orbiter's return from space. OEX experiments are
placed within the orbiter structure for data collection, leaving
the payload bay free to support the flight's primary payloads.
SILTS and SEADS previously flew on STS-61C in January 1986 and on
STS-28 in August 1989.
On STS-32, SILTS will gather additional data to predict
thermal protection requirements for the upper surfaces of
advanced entry vehicles. As Columbia slows from orbital speed
down to about Mach 8 (eight times the speed of sound), an
infrared camera located in a pod at the tip of the orbiter's
vertical tail will gather high-resolution infrared imagery of the
upper (leeward) left wing. Researchers will use the data to
produce detailed thermal maps showing the magnitude and
distribution of aerodynamic heating.
On STS-28, SILTS images revealed increased temperatures just
behind the leading edge of the wing and in an area between the
inboard and outboard elevons flight control surfaces which
reached around 1,100 degrees Fahrenheit.
Prior to the experiment's next flight on the STS-35 mission
scheduled for April 1990, the experiment will be reconfigured to
monitor Columbia's upper fuselage.
The SILTS results are vital to the design of advanced winged
spacecraft because each pound of unnecessary thermal protection
that can be eliminated allows another pound of payload to be
carried for the same launch cost. Moreover, SILTS collects data
under flight conditions that can not be duplicated in ground-
based facilities.
SEADS is housed in Columbia's nosecap. The experiment
incorporates 14 penetration assemblies distributed about the
nosecap surface, each containing a small port through which local
surface air pressure is measured.
Measurement of air pressure distribution allows precise
post-flight determination of "air data" such as angle of attack,
angle of sideslip, free stream dynamic pressure and Mach
number. Accurate information on these factors, coupled with
vehicle motion information measured by a separate experiment, are
required to determine the orbiter's aerodynamic flight
characteristics. SEADS provides accurate data during ascent from
liftoff to about 56 miles and from that altitude through landing
during re-entry.
The principal technologists for SILTS are David A.
Throckmorton and E. Vincent Zoby of Langley's Space Systems
Division. Paul M. Siemers III of the Space Systems Division is
the principal technologist for SEADS.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |