NASA Engineering Test May Also Yield Clues to Plant Growth in Space

The engineering test of a plant-growth system to be launched on next week’s
space shuttle mission to the International Space Station also may reveal
important clues about plant development in space.

The Biomass Production System (BPS) is an engineering development unit for
a future International Space Station (ISS) plant habitat capable of
supporting long-term plant growth and botanical experimentation in space.
The STS-110 space shuttle mission, scheduled for launch April 4 from NASA’s
Kennedy Space Center, Fla., will deliver the BPS for in-flight operations
aboard the ISS. The BPS and science samples will return to Earth on the
STS-111 mission, currently scheduled for launch in late May.

“The BPS will allow us to test how best to grow plants in space over
multiple generations,” said Dr. Orlando Santos, chief scientist for the
Space Station Biological Research Project (SSBRP) at NASA Ames Research
Center in California’s Silicon Valley. “The ability to carry out long-term
experiments is a unique characteristic of the ISS facility that is critical
for our understanding of the future of living things in the low-gravity
environments of spacecraft, the moon or Mars.” The BPS is one of several
pieces of science hardware being developed by the SSBRP for use on the ISS.

The primary objective of the BPS is the technology validation test, which
will evaluate hardware performance on orbit in order to select the best
subsystems for design and development of a permanent plant research unit.
Once developed, the plant research unit will be capable of supporting the
continued growth and development of plant specimens and provide the
capabilities necessary to perform scientific investigations for 90 days or
more on orbit. The BPS also will support the Photosynthesis Experiment and
System Testing Operations (PESTO), a study of the effects of microgravity
on photosynthesis and metabolism in wheat plants. Some of the results from
this study also will be used as part of the technology validation test.

The BPS is a powered hardware system that includes four independent plant
growth chambers, a nutrient delivery system, a temperature/humidity control
system, airflow and atmospheric control systems, a video system and a
data-processing system. Each plant growth chamber has a growing area of
about 42 square inches (260 square centimeters) and a height of over 6
inches (15 centimeters). The BPS was developed for NASA by Orbital
Technologies Corp., Madison, Wisc.

The technology validation test will determine the ability of the BPS and
its environmental control subsystems to support plant growth and
development in microgravity. Researchers will study the health and growth
of the plants, facility temperature and humidity controls, nutrient
delivery, lighting, plant manipulation and sample retrieval, video and data
acquisition, and performance of other operations and support systems.

The testing process will use two types of plants — Brassica rapa and
Apogee wheat. Brassica plants include such commonly grown vegetables as
broccoli, cabbage, cauliflower, rutabaga and turnip. Brassica is a dicot, a
plant with two cotyledons, or leaf-like structures, per seed, and exhibits
multiple developmental stages (growth, flowering and seedpod production) in
a short time. The growth of Brassica rapa seedlings will test the ability
of the BPS to support the growth of a developmentally complex plant. Dr.
Robert Morrow, Orbital Technologies Corp., Madison, Wisc., is the principal
investigator.

Four-day-old Apogee wheat seedlings– a monocot plant with one cotyledon,
or leaf-like structure, per seed — also will be exposed to a variety of
temperature and humidity levels to test the ability of the BPS to control
temperature and humidity set points. In addition, water utilization and
plant photosynthesis will be measured. Plant tissue will be harvested and
frozen or fixed when the plants are 21 days old.

PESTO will study the growth, photosynthesis, gas exchange and metabolism of
Apogee wheat in microgravity. This experiment will determine the ability of
wheat seeds to germinate, develop and grow in microgravity conditions,
measure the growth of the seedlings, and determine the effects of
microgravity on photosynthesis and transpiration. The PESTO principal
investigator is Dr. Gary Stutte, Dynamac Corp., Kennedy Space Center, Fla.

Understanding photosynthesis is a critical component of plant-based
atmospheric regeneration systems now under study for possible use in future
long-duration space missions. By generating oxygen, removing carbon dioxide
and purifying water, living plants could help maintain proper spacecraft
atmosphere, and reduce the costs of air and water resupply on long-duration
missions. This research also will have direct application to future
production of crops that the ISS crew could eat, such as radishes, lettuce
or onions.

The BPS testing and research are supported by NASA’s Office of Biological
and Physical Research, which promotes basic and applied research to support
human exploration of space and to take advantage of the space environment
as a laboratory. More information is available at:
http://spaceresearch.nasa.gov/

For information about NASA’s Space Station Biological Research Project, go
to: http://brp.arc.nasa.gov/

Details about the BPS are available at: http://lifesci.arc.nasa.gov/UF1