Lada: The ISS Plant Substrate Microgravity Testbed

Abstract

Lada, named for the ancient Russian Goddess of Spring, is a plant growth system developed jointly by the Space Dynamics Laboratory and the Institute of Biomedical Problems for longterm deployment on the International Space Station. Lada uses design features and technology similar to the Svet greenhouse on the Mir orbital outpost, and will be launched to ISS in June 02. It is scheduled to support its first crop (a leafy vegetable-Mizuna [Brassica rapa var. nipposinica]) in October 02. Lada consists of four major components (a control module, two vegetation modules and a water tank) and is designed to be deployed on a cabin wall. This deployment scheme was chosen to provide the crew therapeutic viewing and easy access to the plants. The two independently controlled vegetation modules allow comparisons between two vegetation or substrate treatments. The vegetation modules consist of three sub-modules, a light bank, the leaf chamber, and a root module. The root module is 9 cm deep, and can be instrumented to allow a wide range of substrate water and oxygen diffusion experiments to be conducted during the plant growth experiments. Sensors available in Lada are similar to those provided by the Svet-GEMS system. Specific attention has been paid to the root zone sensor suite, which includes substrate moisture probes, minitensiometers, and substrate oxygen sensors. Experiments conducted in Lada will be associated with the Russian National Science program and will follow three themes: substrate management physics, plant production and quality, and crew-plant interaction studies. A unique feature of the Lada concept is that when the system is not being used for supported science experiments, it will be available to crew members to supplement their diet and to enhance flight enjoyment. Plans are in place to train all of the Russian crew members to use Lada. International cooperative experiments exploiting these unique features are now being developed.

Gas Diffusion Measurement and Modeling in Coarse‐Textured Porous Media

“…A microliter metered peristaltic pump (Instech Laboratories, model P625, Plymouth Meeting, PA) controls water additions or removal at 144 μL per revolution. A heat‐pulse moisture sensor and tensiometer provide confirmation of the substrate water content and energy status, respectively (Bingham et al, 2002). Galvanic oxygen sensors (Model R22D, Teledyne Analytical Inst., Los Angeles, CA) on the top of each gas chamber continually monitor O 2 concentrations during the diffusion process.…”

Microgravity Oxygen Diffusion and Water Retention Measurements in Unsaturated Porous Media aboard the International Space Station

“…For both designs, nine cells were combined into a unified system capable of running independent diffusion and water retention, allowing measurements in triplicate samples of Turface, Profile, and Mix. The experiments were fully automated using the Lada control module (Bingham et al, 2002) and required minimal cosmonaut intervention in microgravity. For the detailed design and operation of the diffusion cells, we refer the reader to Jones et al (2003a); here we give a brief description of the measurement apparatus and conduction of the experiment.…”

“…For example, GEMS measured soil water contents and air composition. With the advent of the International Space Station (ISS), the gained knowledge from the SVET and GEMS greenhouse resulted in a new space greenhouse called Lada (Bingham et al, 2002). Lada was aimed at advancing substrate management physics, plant production, and cosmonaut–plant psychological benefits.…”

Host-Microbe Interactions in Microgravity: Assessment and Implications

“…Plants cultivated in space flight conditions have been grown in various media, including agar plates, growth pouches, absorbent “floral foams”, and in sub-irrigated porous arcillite (calcined clay chips) [ 92 , 93 ]. These studies have often used specialized growth chambers (e.g., Astroculture, the Biomass Production System, Lada, and others), which typically control light, humidity, carbon dioxide and regulated temperature [ 18 , 90 , 92 , 94 , 95 , 96 , 97 , 98 ]. Some of these chambers, such as the Russian Svet (on Mir) and the Lada on the International Space Station (ISS) are open to the cabin air [ 97 ] and hence exposed to the organic volatiles and very high CO 2 levels of the cabin air, which can affect the plants in ways unrelated to microgravity [ 99 , 100 ].…”