PHOTOSYNTHESIS EXPERIMENT AND SYSTEM TESTING AND OPERATION (PESTO)
Research Area: Plant Biology
Expedition(s): 4
Principal Investigator(s): ● Gary W. Stutte, PhD, Dynamic Corporation, Cape Canaveral,
Florida
RESEARCH OBJECTIVES
Photosynthesis Experiment and System Testing and Operation (PESTO) studies the
photosynthetic response of plant tissues grown in microgravity. Results can lead to the
development of regenerative life support systems on future missions to the moon or Mars.
EARTH BENEFITS
As less fertile land becomes available
to grow food, alternative agricultural
systems that efficiently produce
greater quantities of high-quality
crops are increasingly important.
Data from the operation of the PESTO
can advance greenhouse and
controlled-environment agricultural
systems and help farmers produce
better, healthier crops in a small
space using the optimum amount of
nutrients.
SPACE BENEFITS
The amount of food necessary to
sustain a crew during a long-duration
mission to Mars would prohibitively increase the mass of spacecraft and the overall cost of the
mission. A possibility to alleviate this problem could be the use of plant systems as food sources
or for regenerative life support systems. The biomass production systems may also be used as a
filtration system for water and atmospheric gases.
RESULTS
During International Space Station (ISS) Expedition 4, PESTO grew 32 plants for 73 days inside
the plant growth chambers of the Biomass Production System (BPS). Following return to Earth,
these plants were compared to ground controls that were grown in BPS plant growth chambers
on Earth.
The PESTO investigation had 3 dimensions that resulted in a more complete picture of
microgravity influences on photosynthesis: gas exchange, partitioning, and metabolism. Carbon
dioxide and light response curves allowed researchers to establish whether canopy
photosynthetic responses were affected by space conditions. This is noteworthy since plants
can be used to regenerate the atmosphere in space conditions through removal of carbon
ISS004E10138 – Close-up view of Apogee Wheat Plants with a
scale as backdrop to exhibit the growth of the plants grown as part
of the Photosynthesis Experiment and System Testing and
Operation on ISS Expedition 4.