RESEARCH:
LUNAR CROP PRODUCTION & FAILURE ANALYSIS |
|
|
Loss
of environmental control in controlled environments is far more
common than biological failures from disease and insects or
cultural problems from human error.
Mitigating the effects of power loss with
low temperature and low light.
The most common and most significant environmental failure is
loss of electrical power, which results in prolonged darkness.
We studied lettuce, radish, tomato, and spinach and found that
the effects of prolonged darkness can be mitigated with low
temperature (3 to 12 ºC depending on species) or low light
(5 to 10 μm-2 s-1). |
CLICK ON THESE TITLES TO JUMP TO THE
ABSTRACTS BELOW:
|
|
|
-
Crop
Production on the Lunar Surface: Mitigating the Effects
of Prolonged Darkness with Reduced Temperature and Low Light
Bruce Bugbee, J. Chard, and G. Akula
Presented
by Dr. Bruce Bugbee at
NASA
Bioastronautics Investigator's Workshop
Jan. 13-15, 2003; Galveston, TX
|
BACKGROUND We
have sought to optimize conditions for crop yield for many years,
but optimal conditions will not always be cost effective.
More importantly, environmental control systems routinely fail,
and we need to learn how to gracefully recover from these
failures.
Failures of the power supply system are among the most common and
most detrimental of all system failures. A battery back-up
could supply a small amount of power during a power outage, but we
need to know how to best utilize the back-up power.
Early in this project, it became clear that the detrimental
effects of a power loss could be mitigated by reducing temperature
and adding low light. This was so effective that we began to
investigate crop production using natural light on the lunar
surface. This requires keeping plants alive and healthy
during the 14.7 day-long interval on the dark side of the Moon.
|
|
-
Failure Analysis
Research Summary: Mitigating the Effects of
Prolonged
Darkness with Reduced Temperature and Low Light
Julie Chard, Giridhar Akula, and Bruce Bugbee
|
OBJECTIVE We sought to quantify
the response and recovery of salad crops to 14 days of continuous
power outage. We assumed that 1 to 2% of full power would be
available as back-up power to provide cool temperatures and low
light.
|
|
|
|
ABSTRACT
Either through power loss or lamp
failure, lighting loss is a common failure in controlled
environments. Recovery of plant growth from such a failure will be
critical to the sustainability of an Advanced Life Support System.
Understanding plant response to prolonged darkness can aid in
gracefully recovering from these failures. Using a 10-chamber
canopy gas exchange system (see schematic diagram below) to quantify response and recovery, we
studied canopies exposed to darkness up to 16 days. Canopy
respiration fell to a minimum after 24 to 48-h in the dark and the
plants were surprisingly tolerant of prolonged darkness. We
hypothesized that lowering the temperature during dark periods
would help plants better tolerate prolonged darkness. Indeed,
canopies that were in the cold during the dark periods recovered
much more quickly once light was reestablished with some species
recovering to their pretreatment growth rate within 48-h after an
8 day dark period (see graph at right). Surprisingly, the carbon use
efficiency (the ratio of net photosynthesis to gross
photosynthesis) in all canopies, cold or warm, remained at the
same level.
|
|
-
Prolonged Darkness / Cold Temperatures / Light Quality
Tracy Dougher and B.
Bugbee
|
ABSTRACT The physiology of post-harvest fruits and vegetables is
well understood. Cold temperatures are key to maintaining
post-harvest quality. Recent research (Kubota and Rajapakse, 1996)
has indicated that transplant growth can be ‘suspended’ without
vigor loss for up to six weeks if plants are kept cold and a small
amount of white light is available. Advanced Life Support crops
might be stored in a similar manner if little to no light is
available for full-out crop growth, such as would occur in a
chamber or station power failure.
|
|
-
Failure
Analysis for Advanced Life Support:
Plant Recovery from
Prolonged Darkness
Tracy Dougher, J. Frantz,
S. Klassen, and B. Bugbee
American Society for Gravitational and Space Biology
Nov. 1999; Seattle, WA
|
ABSTRACT
In an
Advanced Life-Support System, failures of the mechanical systems
can occur in controlled environments, causing plant stress.
Understanding the response and recovery of plants in failure
situations gives us insight into methods to hasten recovery and
minimize yield loss. Interruption of power supply is a common
failure in these systems. We utilized a ten-chamber gas exchange
system to quantify the photosynthetic and carbon use efficiency
recovery of crops from prolonged darkness. At various growth
stages, lettuce, soybean, and wheat plants were kept in the dark
for 0 to 4 days to mimic a power outage. One replicate set of 5
chambers was kept at a reduced temperature during the prolonged
darkness to determine if a cold temperature improved tolerance
to darkness. Respiration decreased to near zero after 24 hours
in the dark. Although plants were visibly chlorotic after 2 days
of darkness, photosynthetic and respiration rates recovered to
pre-treatment levels within 48 hours of re-exposure to light,
even after 4 days in the dark. Cold temperature had little
effect on recovery of photosynthesis, but decreased carbon use
efficiency.
|
