When the Space Shuttle
Discovery (STS-114) returns to flight next month, it will have a
special escort, but the pair of NASA WB-57 chase jets won't just be
along for the ride.
Thanks to an engineering team that includes NASA's Marshall
Space Flight Center in Huntsville, Ala. and key industry partners,
these high-flying chase planes will provide NASA with extra "eyes
in the sky" to watch Discovery's flight and help safeguard its
crew.
The jets will carry innovative, on-board video imaging systems,
dubbed the
WB-57 Ascent Video Experiment, or WAVE project. The system will
capture detailed images of how the Space Shuttle behaves as it
climbs toward orbit.
During the launch, the jets will keep pace with Discovery,
flying at a distance of 15 to 20 miles. The WAVE systems will track
the Shuttle for approximately 150 seconds, from liftoff to
separation of the Solid Rocket Boosters, the power systems that
provide the main thrust to lift Discovery off the pad.
After determining a piece of insulating foam from the External
Tank damaged the Space Shuttle Columbia just after liftoff, the
Columbia Accident Investigation Board recommended NASA improve
imagery during Orbiter ascent.
The chase-plane imagery is part of NASA's response to the
recommendation.
"Shuttle video captured by the chase vehicles will help us see
the launch in greater clarity than ever before," said project
manager Bob Page, who leads NASA's Inter-Center Photography Working
Group at the agency's Johnson Space Center in Houston. "Along with
cameras on the ground, and in and on the Shuttle itself, this
imaging system will provide an unprecedented look at Shuttle
liftoff and atmospheric flight," he said.
NASA video technicians built and tested the high-definition
imaging system earlier this year. They called in optics specialists
from Marshall's Space Optics Manufacturing and Technology Center to
design the telescopic optics to simultaneously record the Shuttle
in visible light and infrared.
Mechanical engineers from the Marshall Center and the University
of Alabama in Huntsville, Ala., designed the housing. Marshall's
Mission Operations Laboratory helped develop software to control
the infrared camera and recorder. Huntsville engineers working for
San Diego-based SAIC, a NASA contractor, helped integrate the
cameras and recording system.
"This was the very definition of a team effort," said Marshall
engineer John West of the Space Optics Manufacturing and Technology
Center. "In June 2004, we were looking at nothing more than a
concept on a drawing board. In nine months, we built two complete
imaging systems."
Just one issue remained: how to get the complex, bulky WAVE
systems airborne. Each system had to be mounted in the nosecone of
the chase planes, using a large gimbal, a stabilizing anchor to
keep the cameras focused on the Shuttle, even if turbulence caused
the plane to dip or drift. The WAVE team turned to Southern
Research Institute in Birmingham, Ala., for the solution: a gimbal
system similar to ones the firm built to support U.S. Army missile
tests.
According to John Collier, senior program manager for SRI, the
company designed and built a new gimbal to suit NASA's needs by
using a lightweight, carbon-graphite epoxy. In March, the firm
integrated the WAVE systems with the gimbals. The systems will be
shipped this month to Ellington Airfield near Houston, where they
will be mounted on the jets.
"Across the Agency, we're all working to make the Space Shuttle
safer," said Marshall project lead Rodney Grubbs. "This was our
opportunity to contribute, and we're excited about what our imagery
might mean for the safety of our astronauts."
Managed by JSC, the WB-57s are former U.S. Air Force planes
designed to study weather conditions at high altitudes. When the
Air Force phased out its WB-57s in the 1970s, it transferred two of
the jets to NASA. NASA's are the last two WB-57s still flying.