T. Shane Topham

Lada: The ISS Plant Substrate Microgravity Testbed

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.

An Automated Oxygen Diffusion Measurement System for Porous Media in Microgravity

Note: SAE Technical Paper 2003-01-2612 Reference LASEP-CONF-2003-001 Record created on 2007-08-24, modified on 2016-08-08

Observational study: microgravity testing of a phase-change reference on the International Space Station

Background:Orbital sensors to monitor global climate change during the next decade require low-drift rates for onboard thermometry, which is currently unattainable without on-orbit recalibration. Phase-change materials (PCMs), such as those that make up the ITS-90 standard, are seen as the most reliable references on the ground and could be good candidates for orbital recalibration. Space Dynamics Lab (SDL) has been developing miniaturized phase-change references capable of deployment on an orbital blackbody for nearly a decade.Aims:Improvement of orbital temperature measurements for long duration earth observing and remote sensing.Methods:To determine whether and how microgravity will affect the phase transitions, SDL conducted experiments with ITS-90 standard material (gallium, Ga) on the International Space Station (ISS) and compared the phase-change temperature with earth-based measurements. The miniature on-orbit thermal reference (MOTR) experiment launched to the ISS in November 2013 on Soyuz TMA-11M with the Expedition 38 crew and returned to Kazakhstan in March 2014 on the Soyuz TMA-10 spacecraft.Results:MOTR tested melts and freezes of Ga using repeated 6-h cycles. Melt cycles obtained on the ground before and after launch were compared with those obtained on the ISS.Conclusions:To within a few mK uncertainty, no significant difference between the melt temperature of Ga at 1 g and in microgravity was observed.