Fascinated with father's steel foundry, NASA scientist now l
by Marshall Space Flight CenterMore articles in People
As a young woman, Sharon Cobb became fascinated with materials when she watched molten metal being formed into huge shapes at a steel foundry in Birmingham, Ala., where her father worked.
Today, she is the lead scientist developing an important facility for studying materials in an out-of-this-world laboratory — the International Space Station.
“Materials science is an integral part of our everyday life,” said Dr. Cobb, a materials scientist at NASA’s Marshall Space Flight Center in Huntsville, Ala. “If you think about the things you use in your daily life, from your coffee cup to the car you drive, you realize that having the right material is a key to how things work. As a materials scientist, I study the chemical and physical make up of materials and use what I learn to make new or improved materials.”
During her 16 years at the Marshall Center, Cobb has participated in several materials science experiments flown on NASA’s Space Shuttle. Cobb is using that experience as lead scientist for the Materials Science Research Rack – soon to be the main facility on the International Space Station for materials science investigations. Astronauts will install the floor-to-ceiling, 40-inch (1-meter) wide rack in the Station’s Destiny Laboratory.
Cobb is working with Marshall Center engineers who are developing the first Materials Science Research Rack and integrating the first two experiment modules that will fit inside the rack. Scientists and engineers completed a critical design review of the research rack in June, which means NASA has approved the design phase and is ready to start building the facility.
Cobb and other scientists will use the rack’s furnaces to melt and solidify many different types of materials. These materials will be processed in orbit, and returned to Earth for characterization.
“Forget science fiction images of huge factories in space,” said Cobb. “Our goal is to use the low-gravity environment created inside a spacecraft – like the Space Station orbiting Earth — to learn how to control the way materials form. Then, scientists can bring that knowledge back to Earth to improve manufacturing processes.”
Manufacturing represents 17 percent — or $1.2 trillion – of the U.S. gross domestic product. That means even modest improvements in materials and their production can have great economic impact. Better materials not only mean better spacecraft, but can also mean better computers, automobiles and buildings.
“The first two fundamental materials science experiments are just getting started on the Station inside the Microgravity Science Glovebox, a new facility that encloses small furnaces and uses gloves to enable the crew to change out samples,” said Cobb. “These initial glovebox experiments will provide data that we can use as we develop more complex experiments in the larger furnaces inside the Materials Science Research Rack. “
The Materials Science Research Rack is scheduled to be delivered to the Station in late 2004. The rack will accommodate two different experiment modules with exchangeable furnace inserts.
“When people ask me why you need different types of furnaces, I explain, that for a simple building project, you usually need several different tools — drill bits, saws and screwdrivers,” said Cobb. “To study materials in space, we need many types of equipment to provide a variety of processing conditions for various types of materials.”
In laboratories at the Marshall Center, Cobb is conducting experiments with materials that may be processed in Space Station furnaces. She works with germanium, a semiconductor used in electronic devices and mercury zinc selenide, a material that has the potential to be a new state-of-the art infrared detector which could be used to map temperature variations in everything from human bodies to rockets.
Engineers are using the Marshall Center Microgravity Development Laboratory to help design, build and test the Materials Science Research Rack and one of its furnace inserts. Marshall engineers are building a flight-like Quench Module Insert Furnace that will be tested at Marshall and then delivered to the European Space Agency, which is responsible for building the Materials Science Laboratory Experiment Module– the systems that will power, cool, and control the furnace.
At the Microgravity Development Laboratory, furnace operations are tested by melting and solidifying pure aluminum samples inside a breadboard model of the furnace to 1652 degrees Fahrenheit (900 degrees Celsius). The flight furnace will operate at temperatures up to 1400 degrees Celsius (2550 degrees Fahrenheit). The furnace is lighter and uses less energy to operate than most of the furnaces flown earlier on Shuttle missions. It weighs 55 pounds (25 kilograms) versus several hundred pounds and it operates with 200 watts of power versus 2500 watts of power.
The other experiment module that will initially be installed in the Materials Science Research Rack is being built by the Consortium for Materials Development in Space at the University of Alabama in Huntsville — one of 15 NASA Commercial Space Centers sponsored by NASA’s Space Product Development Program at the Marshall Center. This experiment module has two exchangeable furnaces that will be available to commercial companies to process semiconductors, optical glass preforms, metals and composites in space. Both furnaces are modular and can be removed for repairs or replacement.
The Telescience Support Center, also located in the Microgravity Development Laboratory, will be used to monitor and control experiments in the Materials Science Research Rack once it has been installed on the Station.
Flight-like training models of the Materials Science Research Rack including its experiment modules will be delivered to the Johnson Space Center in Houston, Texas, for astronaut training. To ensure astronauts know the importance of doing materials science experiments, Cobb teaches an introductory materials science class at the Johnson Center — including hands-on laboratory experiments — to new astronaut candidates.
While a few of the astronaut candidates have advanced degrees in materials science, many are pilots, astrophysicists or from other unrelated fields. To perform these experiments aboard the International Space Station, it is important for the astronauts to understand how and why materials are studied in space.
“I always tell the astronauts that the goal of materials processing in space is to develop a better understanding of how processing affects materials properties and structures, said Cobb. “With this knowledge, we can reliably predict conditions required on Earth to achieve improved materials.
Cobb, a Birmingham native, earned a doctorate degree in materials science and engineering from the University of Florida in Gainesville and bachelor’s and master’s degrees in materials engineering from the University of Alabama at Birmingham.
She has recently been selected to participate in the NASA Professional Development Program. This leadership training program provides participants with an opportunity to broaden their understanding of NASA agency goals and policies, and facilitates communication with other NASA field centers and government agencies.
As a part of this program, she recently was assigned to NASA Headquarters in Washington, DC for one year. The Materials Science Research Rack and its experiments are sponsored by NASA’s Office of Biological and Physical Research.