Plant Biology Program
Hardware
Think of it as a big box filled with everything a plant needs to grow. Or a really small greenhouse, packed with 180 sensors (including imaging capabilities) and the capacity to control air, temperature, humidity, and water from the ground. Our APH can grow plants for up to 135 days. That’s enough time to conduct multi-generational studies looking at temperature, relative humidity, carbon dioxide level, light intensity, and spectral quality.
We couldn’t come up with a clever acronym for our hardware that provides high-growth plant volume and low resource consumption, so we called it Veggie. The Vegetable Production System provides an LED light bank, nutrients, and water and is designed to grow fresh, nutritious vegetables in space for consumption by astronauts onboard the ISS. In addition to producing salads in space, Veggie can support a variety of experiments designed to determine how plants respond to microgravity.
BRIC-PDFU experiments take place in enclosed canisters designed to host a variety of experiments. Recent research includes work on plant seedlings, callus cultures, and microbes. Typically, biological specimens are placed in Petri dishes, where crew members perform specific operations in orbit as directed by Principal Investigators. BRIC-PDFUs provide researchers with the capability to expose their science specimens to two different solutions, such as growth media and/or fixatives.
We designed the BRIC-LED to test how plants and other organisms grow under different lighting conditions. Four customizable diodes emitting discrete wavelengths of LED light (blue, red, far-red, and white) are available for each Petri dish and can be configured as specified by the investigator.
Initially a simple anodized-aluminum cylinder used to provide passive stowage for investigations into the effects of spaceflight on small specimens, the Biological Research in Canisters (BRIC) hardware has been adapted over time to accommodate various specimens with increasingly more complex requirements for investigations during spaceflight.
BRIC-60 consists of an upper and lower chamber that can fly as a half canister (lower chamber + lid) or full canister (upper chamber + lower chamber + lid). BRIC-60 maintains a light-tight environment inside the canister chamber. BRIC-60 can hold a maximum of 12 60mm Petri dishes per half canister (a total of 24 per full canister) or 13 Teflon tubes per half canister (a total of 26 per full canister) that can be placed inside each canister chamber. BRIC-60M is an enhanced version of the BRIC-60 lower chamber that includes two gas-sampling ports capable of drawing gas from two axial heights within the canister volume.
Specimens flown in BRIC-60 include Lycoperscion esculentum (tomato), Arabidopsis thaliana (thale cress), Glycine max (soybean) seedlings, Physarum polycephalum (slime mold), Pothetria dispar (gypsy moth) and Ceratodonpurpureus (moss).
BRIC-100 canisters have threaded lids on each end that allow for a breathable configuration. This configuration allows passive gas exchange of oxygen and carbon dioxide through a semi-permeable membrane. The vented BRIC-100 configuration is not a light-tight container; however, if gas exchange is not required the breathable lid (containing the semi-permeable membrane) can be replaced with a solid lid providing a sealed, closed experimental environment. The bottom and top lids of each breathable canister have 25 1.0 cm holes and a Teflon membrane (pore size 0.5 µm). Two septa located in the lid allow for gas sampling. BRIC-100 can accommodate nine 100-mm Petri dishes. Specimens flown in the BRIC-100 mm Petri dish (BRIC-100) include Manduca sexta (tobacco hornworm) pupae, Hemerocallis lillioasphodelus L. (daylily) and Dactylis glomerta L. (orchard grass) embryos.
BRIC-100VC is a completely sealed, anodized-aluminum cylinder providing containment and structural support of the experimental specimens. The BRIC-100VC canister has been optimized to accommodate standard 100-mm Petri dishes or 50 mL conical tubes. Depending on storage orientation, six or nine canisters can be flown within an ISS stowage locker. The top and bottom lids of the canister include rapid disconnect valves for purging the canister with selected gases of a defined composition. These specialized valves allow for specific atmospheric containment within the canister, providing a gaseous environment defined by the investigator. Additionally, the top lid has been designed with a toggle latch and O-ring assembly allowing for prompt sealing and removal of the lid. The external dimensions of the BRIC-100VC canisters are 16.0 cm (height) x 11.4 cm (outside diameter). The lower portion of the canister has been equipped with sufficient storage space for autonomous temperature and relative humidity data loggers.
The Kennedy Space Center Fixation Tube (KFT) is a triple redundant, sealed environment apparatus for storing stabilized/preserved plant or other small biological samples during flight. The samples are returned to Earth for subsequent molecular biological analyses. Because KFT quickly preserves samples, it holds potential for long-term storage without compromising RNA integrity, which makes it ideal for plant gene expression investigation. The KFT stow and descent procedures enable KFTs filled with RNALaterTM to be deployed for months or possibly years prior to use.
PONDS is a new plant growth approach that contains both an area for a contained plant growth substrate and a reservoir for water and/or plant nutrient solutions. It was developed to fit under the Veggie light cap and replace the current Reservoir/Pillow Nutrient Delivery System used within Veggie on ISS. The system provides more reliable water delivery to seeds for germination (while avoiding overwatering), and fulfills the requirement to transport water from the reservoir for improved plant growth while providing adequate nutrients and aeration to the root zone under both 1g and microgravity conditions.
Spectrum is a multi-fluorescent imaging system that provides environmental control for optimal growth of biological specimens. Spectrum’s high resolution, 71MP monochromatic camera captures images of in vivo gene expression. Images can be downlinked in near real-time to researchers back on Earth for analysis. Spectrum’s modular design allows customization of the facility as required by the research objectives. Spectrum’s standard configuration accommodates up to four Petri plates installed onto Spectrum’s carousel assembly within the Environmental Research Chamber (ERC). Growth lighting (red, blue, green, white, and far-red LEDs) is strategically positioned above the carousel for providing the energy necessary for the photosynthetic process to occur. Spectrum’s data commanding software allows ground crews to control the growth lighting, CO2 levels, and ethylene levels throughout the experiment while routinely capturing images and telemetering these images back to Earth.
