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Fact sheet number: FS-2001-11-187-MSFC
Release date: 11/01

Expedition Four

Mission: Growth Chamber Number 2 up on Expedition Four, ISS Flight UF-1, STS-108 Space Shuttle Flight and down on Expedition Four, ISS Flight 8A, STS-110 Space Shuttle Flight

Experiment Location on ISS: Expedite the Process of Experiments to Space Station (EXPRESS) Rack 4

Principal Investigators: Tad Theno and Eric Brunsell, chief program scientists for Space Explorers Inc., and Dr. Weijia Zhou, Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison

Co-Principle Investigator: Dr. Bratislav Stankovic, WCSAR

NASA Commercial Space Center Director: Dr. Weijia Zhou, WCSAR

NASA Commercial Space Center Manager: Annie Matisak, Space Product Development Program, NASA Marshall Space Flight Center, Huntsville, Ala.

The ADVANCED ASTROCULTURE ™ is the first facility being used to grow plants on the Space Station. Its technology is based on the ASTROCULTURE™ plant growth unit, flown on NASA's Space Shuttle and the Mir Russian Space Station. Potatoes were grown during a 1995 Shuttle mission. The plant growth unit was designed and built by the Wisconsin Center for Space Automation and Robotics (WCSAR).
The ADVANCED ASTROCULTURE ™ is the first facility being used to grow plants on the Space Station. Its technology is based on the ASTROCULTURE™ plant growth unit, flown on NASA's Space Shuttle and the Mir Russian Space Station. Potatoes were grown during a 1995 Shuttle mission. The plant growth unit was designed and built by the Wisconsin Center for Space Automation and Robotics (WCSAR). (NASA/MSFC)


How can industry take advantage of growing plants in the unique microgravity environment created as the International Space Station orbits Earth? The Wisconsin Center for Space Automation and Robotics at the University of Wisconsin-Madison -- a NASA Commercial Space Center with partners in industry and academia -- is dedicated to helping industry explore the possibilities.

With the help of NASA's Space Product Development Program at the Marshall Space Flight Center in Huntsville, Ala., the Wisconsin Center for Space Automation and Robotics has developed a series of plant growth units dedicated to conducting plant biotechnology research sponsored by commercial companies. The plant growth units are designed especially to operate in the microgravity or low-gravity environment created as the Space Station orbits Earth.

The ADVANCED ASTROCULTURE™, consists of a plant growth chamber and life support systems, which fills two single middeck lockers. It builds on proven ASTROCULTURETM technologies flown on seven previous space flights on the Space Shuttle and one flight on Space Station Mir.

The first ADVANCED ASTROCULTURE™ plant growth unit was used successfully to grow plants during Space Station Expedition Two. These plants were returned to investigators on Earth on the STS-104 Space Shuttle mission in July 2001.

During their stay on the Station during Expedition Two, the plants went through seed germination, plant growth and development, seed formation, and seed maturation -- completing an entire lifecycle. In general, the plants grown in ADVASC were healthy, and were growing well when the experiment was completed and powered down. Seedpods, called siliques, containing mature seeds were produced in flight and were later harvested after the plants were returned to scientists on the ground. No abnormalities in the plants' physiology were discovered. The hardware performed very well, especially considering that Expedition Two was its first flight.

Of the 91 Arabidopsis seeds that were launched, about 90 percent germinated in space; and about 70 percent of the seeds grew to produce siliques that contained mature seeds. An average of 24 siliques per plant were produced, each containing an average of 36 seeds. The majority of siliques were rated as mature, while the remainder were moderately mature.

The objectives of the Expedition Two ADVANCED ASTROCULTURE™ experiment were (1) to evaluate the performance of plant life support technologies/systems for long-term operation in microgravity; (2) to determine whether Arabidopsis thaliana, a member of the Brassica plant family that includes species such as cabbage and radishes, can complete its seed-to-seed life cycle in microgravity; and (3) to compare the phytochemistry of the seeds produced in space with seeds harvested on Earth.

Based on the success of the first experiment (ADVASC-01), Space Explorers Inc. will again be the commercial partner with the Wisconsin Center for Space Automation and Robotics, conducting an experiment on Space Station Flight UF-1. This is a follow-up to the first experiment. It will allow the growth of a second generation of Arabidopsis thaliana plants, using seeds harvested from plants grown during Expedition Two, and also from new seeds. These experiments are both part of Space Explorers' Orbital Laboratory.

Space Explorers Inc. specializes in producing Internet-based, space education programs. The firm has created and marketed the "Orbital Laboratory" program -- a school kit and Internet multi-media educational program that allows students to design, conduct and analyze the space experiment on the Space Station. Using the kit, students can compare data through an online student experiment database.

After the experiment is completed on the Space Station, students can use actual data from the experiment to recreate the experiment in a virtual environment. The program is the first-ever, student-designed experiment aboard the Station, and the first in a series of commercial payloads used for educational purposes by Space Explorers.

The program is being marketed to kindergarten through high school classes worldwide and already is being used by hundreds of schools. Schools can purchase a kit containing the necessary materials to conduct the plant experiment. They also receive access to the Orbital Laboratory curricula, to plant data from the ADVANCED ASTROCULTURE™ experiment on board the Station and to data from other participating schools. Schools can participate in Web chats with personnel involved in the mission, and have access to many other program features. The product also will be sold retail for home schools and consumers.

As scientific analysis is completed on plants grown on the Space Station, the program will be updated. The students will be able to compare plants they grew on Earth with first-generation plants grown during Expedition Two and second-generation plants grown during Expedition Four.

Experiment Operations

The plant growth chamber to be delivered to the Space Station during Expedition Four will allow plant scientists to continue their long-term plant research in a microgravity environment. Since the best-ever seeds produced in space were harvested after Expedition Two, scientists can study the entire plant life cycle -- from seeds to plants to seeds.

To accomplish this, the ADVANCED ASTROCULTURE™ provides a completely enclosed, environmentally controlled plant growth chamber that was first successfully demonstrated inside the ASTROCULTURE™ during Shuttle and Mir missions. The growth chamber is larger, enabling plants to grow bigger. The ADVANCED ASTROCULTURE™ controls temperature, humidity, light, atmospheric conditions and delivery of nutrients to plants. It requires no power during Shuttle ascent and descent.

Before the flight, scientists plant seeds in a root tray using a dry rooting material called Arcillite, a type of crushed clay. The seed tray is then attached to the ADVANCED ASTROCULTURE™ growth chamber. Reservoirs in the growth unit are loaded with water and nutrient solutions that plants need to live while aboard the Space Station.

The equipment is configured as two single middeck lockers that insert separately into a Space Station EXPRESS Rack. One locker contains the support systems. The other contains the plant growth chamber and ancillary hardware. This arrangement allows the support system to remain on board, while the Shuttle transports plant growth units to and from the Station with different experiments.

For the Expedition Four experiment, the payload has been modified. A hatch was added so the crew can remove plant tissue while the plants are growing on board the Station. The plant samples will be stored in tissue fixation tubes, designed by NASA's Kennedy Space Center in Florida. Then, they will be placed inside the Station's Biotechnology Refrigerator. The plant tissues' RNA genetic information will be preserved, which will allow scientists and the commercial partner to study microgravity impact on plants' gene expression levels after the plants are returned to Earth.

The objectives of the Expedition Four ADVANCED ASTROCULTURE™ experiments are (1) to validate plant life support technologies used in the ADVASC payload; (2) to produce the second generation of seeds in space from the first generation produced during Expedition Two; and (3) to conduct a gene expression analysis to determine whether microgravity may alter plant gene expression levels.

Growth Chamber Number 2 will be delivered to the Space Station on the Space Shuttle Endeavour for the STS-108 mission, scheduled to launch in November 2001. On the ninth day of the mission, the crew will move the growth unit to the U. S. Laboratory Module, Destiny, and install it in EXPRESS Rack No. 4. No later than 17 days after the launch, the crew will activate the experiment by powering up the plant growth unit.

The system will automatically deliver fluid and nutrients to the root tray, and the seeds will germinate. The ADVANCED ASTROCULTURE™ will operate autonomously for 50 to 55 days. During the plant growth period, the crew will sample nutrients, gases and plant transpiration inside the plant growth chamber three times -- early, middle and late in the experiment cycle. These samples will be chemically preserved and stored in the Biotechnology Refrigerator. After the flight, investigators can analyze the samples to determine how healthy the plants were during various growth phases.

On a routine basis, the crew will monitor the plants' status by checking displays on the front panel of the support system unit and by observing the plant video. Science telemetry and video from the ADVANCED ASTROCULTURE™ will be transmitted via the Telescience Resource Kit (TReK) system to scientists at their operations center at the University of Wisconsin-Madison.

At 30 days, or about halfway into the experiment, the crew will replenish the nutrient solution by refilling the nutrient reservoir to maintain the desired concentration of nutrients. The experiment will end in about 50 to 55 days when the plants are expected to produce mature seeds. The growth unit, along with the enclosed plants and the collected sample material from the plants, will be returned to Earth during Expedition Four on Space Shuttle Atlantis on the STS-110 mission, ISS Flight 8A, scheduled for March 2002. After landing, all the ADVANCED ASTROCULTURE™ hardware, the plants and plant sample material will be returned to scientists for analysis.

Flight History/Background

The ASTROCULTURE™ plant growth chamber, a precursor to the ADVANCED ASTROCULTURE™, has flown on seven Space Shuttle flights and one long-duration Shuttle/Mir mission. On STS-95 in October/November 1998, a commercial company, International Flavors and Fragrances in New York, sponsored a miniature rose experiment and has used its findings to enhance product development. Other plants that have flown inside the ASTROCULTURE™ include wheat, Brassica rapa plants and potatoes.

Plants were grown and produced seeds inside the ADVANCED ASTROCULTURE™ during its earlier flight on International Space Station Expedition Two.


This will be the first experiment to see if seeds initially grown in space can germinate, grow, and produce more mature seeds in space. This will be the second Space Station experiment in which plants will be grown for a period long enough to prove they can produce seeds. Since the Space Station will remain in orbit for more than a decade, it provides an ideal laboratory for growing plants and studying the influence gravity has played as plants evolved on Earth.

Prior experiments with soybean gene transfer suggest that the Agrobacterium-based transformation technique -- the process of using bacteria as a vector to deliver desirable DNA into soybean cells, such as those that enhance disease resistance to plants -- work more effectively in microgravity.

Scientists recently announced the first mapping of the entire genetic code of a plant. The plant was the Arabidopsis -- the same plant group selected for the Expedition Two flight. Researchers predict this genetic map will make genetic modification of crops more refined, precise, predictable, and thus safer, and more accepted by consumers. The ADVANCED ASTROCULTURE™ experiments explore the benefits of using microgravity to create tailor-made crops that withstand inhospitable climates, resist pestilence, and need less space to grow. These are all qualities that would also benefit future space explorers growing plants on new worlds.

As with any new technology, there are often unexpected technologies that benefit people on Earth. As they built their plant growth chambers, the Wisconsin Center for Space Automation and Robotics needed a light source that would be small but provide enough energy to stimulate plant growth.

Researchers discovered that lights very similar to those designed to grow plants inside ASTROCULTURE™ could be made to emit wavelengths of light that stimulate tumor-killing drugs and heals wounds. NASA is funding research by physicians at the Medical College of Wisconsin in Milwaukee to study how these related light-emitting diodes can provide valuable medical treatments for people on Earth and in space.

More Information

More information on the ADVANCED ASTROCULTURE™ experiment and other experiments is available at:

Steve Roy
Public Affairs Office
(256) 544-0034

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