Ames plant-growth hardware passes test
Scientists at Ames received the first images of plants growing in the Biomass
Production System (BPS) aboard the International Space Station (ISS) just four
days after the STS-110 space shuttle mission carried it into orbit. They also
acquired the ability to send commands to the orbiting plant-growth system. On
April 18, orbiting astronauts harvested the first wheat from the unit. Astronauts
had transferred the BPS from the space shuttle Atlantis to the ISS not long after
the shuttle docked to the space station.
The Biomass Production System is an engineering development unit for a future
ISS plant habitat capable of supporting longterm plant growth and botanical experimentation
in space. The BPS and science samples will return to Earth on the STS-111 space
shuttle mission, currently scheduled for a late May launch.
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.
"BPS is a versatile piece of hardware, and the team is excited about this
first chance to test its capabilities on orbit in support of current and future
science experiments," said Dr. Randy Berthold, BPS payload manager. The BPS
is one of several pieces of science hardware being developed by Ames Space
Station Biological Research Project (SSBRP) for use on the space station.
"Although the BPS is the third suite of flight hardware Ames has provided
to the ISS, this marks the first time Ames has controlled any of the hardware
from the ground," Berthold said. A 2001 space shuttle mission carried an
autonomous radiation monitoring and recording system to the ISS. Later that year,
the Avian Development Facility was carried on a mission to the ISS, although the
facility remained on board the space shuttle.
Each day, the BPS team sends commands to the unit and retrieves the previous
days data files, seven in all. Pictures of the plants included in these
files help the investigators determine how well the plants are developing. Commands
also can be sent to the BPS to change the timeline for automated activities that
were programmed into the unit preflight.
"The BPS allows us to test how best to grow plants in space over multiple
generations," said Dr. Orlando Santos, former chief scientist for SSBRP.
"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 primary objective of the BPS is the technology validation test, which evaluates
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 supports 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
The testing process uses 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
Four-day-old Apogee wheat seedlings-- a monocot plant with one cotyledon, or
leaflike structure, per seed -- also were 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 was harvested and frozen or fixed when the plants were
21 days old.
PESTO studies 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.
STS-110 ended with the successful landing of Atlantis at Kennedy Space Center
on April 19. In addition to Berthold, Ames personnel who have key roles in supporting
the BPS project include Kristina Lagel, project scientist; Dr. David Heathcote,
project operations lead; Robert Yee, hardware contract monitor; and Dr. Charles
Wade, Code S chief scientist.
The BPS testing and research are supported by NASAs 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.
for more information. To learn more about NASAs Space Station Biological
Research Project, visit http://brp.arc.nasa.gov
By Ann Hutchison, NASA Ames Research Center, Astrogram May 2002
For a printable PDF version of this research visit page 11 of http://amesnews.arc.nasa.gov/astrogram/2002_astrograms/05_02Astrogram.pdf