Capabilities of the Advanced Astroculture plant growth unit to support plant research conducted on the International Space Station

Since 1990, WCSAR has developed a number of technologies for plant-based space life support systems, with a goal of providing robust and capable facilities suitable for conducting quality plant research in microgravity environment. These technologies have been substantially validated using the Astroculture payload through a series of space shuttle flights. Advanced ASTROCULTURE^TM (ADVASC), a space-based plant growth unit, has been developed to take advantage of plant research opportunities during the early assembly phase of the International Space Station (ISS) when ISS resources and up/down mass availability are limited. ADVASC provides an enclosed, environmentally controlled plant growth chamber with controlled parameters of temperature, relative humidity, light intensity, fluid nutrient delivery, and CO₂ and hydrocarbon (ethylene) concentrations. Auto-prime technology eliminates the need for electrical power during launch vehicle ascent/descent, and therefore greatly relieves the shortage of launch vehicle resources and ISS crew time. State-of-the-art control software combined with fault tolerance and recovery technology significantly increases overall system robustness and efficiency. Tele-science features allow engineers and scientists to remotely receive telemetry data and video images, send remote commands, monitor plant development status, and troubleshoot subsystems if any unexpected behavior occurs. ADVASC is configured as two single-Middeck-Locker inserts installed in a standard EXPRESS Rack, with one insert containing the support systems and the other containing a large plant growth chamber. Thus, the insert with the support systems can remain on the ISS and only the insert containing the plant chamber needs to be transported to and from the ISS to accommodate different experiments. ADVASC has been used to successfully conduct three plant life cycle studies on board the ISS, two for Arabidopsis seed-to-seed growth and one for soybean seed-to-seed growth. It demonstrated great capabilities in maintaining desired environmental conditions suitable for plant growth in microgravity environment and in recovering system performance caused by unexpected ISS power interruptions.