The April shuttle flight was cut back to four days because of a faulty fuel cell. "Fortunately, we have had an extra three months to fine-tune our hardware and experiments," said Louis Stodieck, associate director of Bioserve Space Technologies Center, headquartered in CU-Boulder's aerospace engineering sciences department.
The payload -- known as the Plant Generic Bioprocessing Apparatus, or PGBA -- and seven experiments were developed by faculty, students and industry affiliates from the center in collaboration with a team at the NASA-Ames Research Center in Moffett Field, Calif. Researchers are using the low-gravity space environment to develop products and technologies in life science, agriculture and medicine.
The 125-pound, automated plant-growth facility will be used to grow food and pharmaceutical and forest plants in space, said BioServe's Alex Hoehn, who headed up design and development of the television-sized plant chamber.
The plant growth chamber is the largest to be flown on a shuttle that can precisely control specific environmental conditions like temperature, humidity, light and carbon dioxide. It also is the first such device with direct data uplink, downlink and video capabilities, said Stodieck, allowing BioServe faculty and students to control and manipulate experiments from the CU-Boulder campus.
Two BioServe experiments sponsored by a large U.S. pharmaceutical company will test the effects of microgravity on plant species known as sweet wormwood and rosy periwinkle. Both plants naturally produce tiny quantities of pharmaceutically important compounds --one plant makes an anti-malarial drug while the other produces precursors to anticancer agents, he said.
Previous BioServe experiments indicate that significantly less lignin -- a substance in plants that affects their strength and stiffness -- is produced in microgravity. "We are hypothesizing that a decrease in lignin production in space may lead to an enhancement in other plant metabolic pathways which are of commercial benefit," said Gerard Heyenga, a principal science investigator on the study from NASA-Ames. "Increased production of plant secondary compounds could ultimately lower the costs of certain pharmaceuticals or lead to the development of new drugs."
"We are entering a new era in space as plans for the construction of the international space station move ahead," said Stodieck. Because much of the cargo shuttle space will be used to ferry building materials into orbit in the coming years, there will be fewer flight opportunities for scientific experiments like those from BioServe, which has flown experiments on 12 shuttle missions, he said.
"But once the space station is assembled, we expect to have near continuous access to space over the long duration needed to complete many of these experiments," he said. While the upcoming Columbia mission will provide nearly 16 days of microgravity, the space station will be able to provide months or even years that may be required for particular commercial investigations, especially those involving plants.
The plant chamber will occupy the "Express Rack" aboard Columbia. Designed by Marshall Space Flight Center, the novel rack will eventually permit experiments to be quickly transferred from NASA shuttles to the International Space Station. Three of the seven astronauts on Columbia have been trained to use the BioServe plant chamber and will help manipulate experiments during the mission.
In cooperation with Dean Foods Vegetable Co. of Green Bay, Wis., BioServe also will fly spinach plants in the chamber. A better understanding of the effects of low gravity on the structure, tenderness and production of sugars, starch and fatty acids in spinach may help researchers develop more tender varieties for dinner tables and heartier strains of vegetables that can withstand severe weather.
BioServe also will fly loblolly pine seedlings for Georgia Pacific of Atlanta to monitor lignin and wood formation. Low-gravity research could benefit the forest products industry by allowing for the eventual development of superior strains of commercial lumber and paper products, said Heyenga.
Researchers and students from Kansas State University, a joint partner in BioServe, will fly additional experiments in the PGBA. One will test the effects of microgravity on tomato gene expression, while the second will investigate methods of infecting cereal crops with nitrogen-fixing bacteria known as rhizobia that naturally benefit legumes like peas and beans by snaring nitrogen from the atmosphere.
Developing ways of infecting crops like corn and wheat with rhizobium could help reduce the need for fertilizers on Earth, researchers believe.
BioServe is a joint center of CU, KSU and industrial affiliates and one of 11 NASA Centers for Space Commercialization with active space flight programs.