The International Space Station will become a better place to take pictures
of Earth with the addition of a new Earth observatory manufactured and
tested at NASA’s Marshall Space Flight Center in Huntsville, Ala.
The Window Observational Research Facility, or WORF, will help Space Station
crews take some of the best photographs ever snapped from an orbiting
spacecraft by eliminating glare and allowing researchers to control their
cameras and other equipment from the ground.
The WORF — manufactured and tested at NASA’s Marshall Space Flight Center
in Huntsville, Ala. — was shipped May 8 from the Marshall Center to NASA’s
Kennedy Space Center in Florida for pre-launch preparations. It is
scheduled for launch aboard the STS-114 Space Shuttle mission in January
2003.
“WORF is designed to make the best possible use of the high-quality research
window in the Space Station’s U.S. lab – the Destiny laboratory module,”
said Rick Turner, WORF project manager at the Marshall Center. “Once Space
Station engineers developed the window, they needed a hardware system to
mountpayloads in front of it to make observations of Earth for a variety of
research. They originally thought of a simple, portable frame, but they
decided they needed more things – like power and computers — than a simple
frame could provide.”
Engineers at the Marshall Center proposed a derivative of the EXPRESS
experiment rack already used on the Space Station and were given the
go-ahead. Designed and manufactured at Marshall, the EXPRESS rack can hold
a wide variety of experiments and provide them with power, communications,
data, cooling, fluids and other utilities – all the things that
Earth-observing experiments would need. WORF will supply payloads with
power, data, cooling, video downlink and stable, standardized interfaces for
mounting imaging instruments.
The refrigerator-sized rack can accommodate payloads up to the size of the
largest aerial photography film camera, with maximum dimensions of 21 inches
(53.2 centimeters) wide by 20 inches (50.8 centimeters) deep and 30 inches
(76.2 centimeters) long. Similar to specialized orbital observatories, the
interior of the rack is sealed against light and coated with a special
low-reflectance black paint, so payloads will be able to observe
low-light-level subjects such as the faint glow of auroras, for example the
Northern Lights around Earth’s poles.
Cameras and remote sensing instruments in WORF can be pre-programmed,
controlled from the ground, or operated by a Station crewmember by using a
flexible shroud designed to cinch tightly around a crew member’s waist.
Consisting of four panes of glass, the lab window is the highest quality
spacecraft window ever flown. The Space Station is an excellent platform
for conducting Earth science. It flies over roughly 75 percent of the
inhabited land surface of Earth, and about 95 percent of the world’s
population. The presence of trained Station crews improves data collected
by WORF experiments. The Space Shuttle’s ability to re-supply the Station
several times a year means WORF payloads can be deployed, recovered
periodically for calibration, repair or maintenance and then re-deployed.
“The window quality is a benefit, but in order to use it to its fullest
extent, you need to be able to mount large optics on a very stable platform
so you don’t lose what you gained in window quality by having your
instrument jumping around,” said Dean Eppler, WORF science manager at NASA’s
Johnson Space Center in Houston. “The WORF represents the part of the
observational system that provides stable mounting capability for even
larger optics than Station crews can use now, as well as the electronics
that will enable an investigator to run their payload from a ground location
without needing extensive crew involvement. It also provides a restricted
enclosure that eliminates glare on the window and provides a good ergonomic
platform for crews to take pictures.”
Space Station crews to date have taken more than 13,000 pictures of our
planet. Results published earlier this year in a peer-reviewed science
journal concluded that the images were achieving 20-foot (6-meter)-
resolution, compared to 10- to 25-meter resolution for higher-altitude
commercial imaging satellites. The improvement is roughly equivalent to
being able to see vehicles on a street from space instead of just buildings.
The WORF was designed and built by the Boeing Co. at the Space Station
Manufacturing Building at the Marshall Center. The specially designed
900-pound (408 kilograms) rack has a payload shelf with 181 mounting holes
and four tracks on each side for attaching payloads. It also includes a
roll-down bump shield to protect the lab window during equipment setup, and
an environmental system to prevent condensation on the window.
Marshall engineers from the Flight Projects Directorate subjected the rack
and its materials to numerous tests to qualify it for flight, including
light-leak, flammability, airflow mapping, electromagnetic interference, and
human interface testing, as well as a vibration analysis.
“These tests ensured that the rack is safe, that it won’t interfere with any
other equipment onboard, and that the rack will enable the crew to take the
best possible photographs,” said Bryan Barley, WORF lead systems engineer at
Marshall.
Kennedy Space Center engineers will do final testing and install the WORF in
the Space Shuttle for launch to the Space Station. Once installed in the
Destiny module, the WORF rack will host a variety of experiments.
The first will be the Earth Knowledge Acquired by Middle School Students
(EarthKAM), an experiment with student participants in schools across
America. EarthKAM allows them to control the camera from their classrooms
on Earth and take pictures from the Space Station. Within hours, students
receive – via the Internet — the pictures they snapped in space.
Earth observation experiments with the WORF and all other science research
operations on the Space Station are managed by the Payload Operations Center
at Marshall. The Marshall Center is one of the primary Space Station
manufacturing facilities, responsible for design and construction of
critical Space Station components, such as the WORF.
The WORF/Lab Window Team earlier this year won one of five Stellar Team
Awards presented by the Rotary National Award for Space Achievement
Foundation. The awards were established to recognize outstanding
individuals and teams from industry and government who have made significant
contributions to the future of the nation’s space program.