The Astroculture™ Plant Growth Chamber (ASC-GC), developed in the early 90s, is a single middeck locker insert space flight payload. The purpose of the ASC-GC unit is to verify the capability and reliability of the various subsystems that can provide an enclosed, environmentally controlled plant growth chamber to support short-term (average of 30 days) commercial or fundamental plant research in microgravity. ASC-GC, designed to operate autonomously, provides precise control of temperature, humidity, atmosphere, lighting, and nutrient delivery. It also features video/data downlink. ASC-GC can be configured with a single chamber or dual chambers in which the environmental conditions for each chamber are independently controlled. Astroculture plant growth unit (ASC-GC) Payload Specialist John Glenn was trained by WCSAR to operate ASC-GC on STS-95. ASC-GC Specifications Growing Space     Single Chamber Configuration: Dual Chamber Configuration (each chamber):           shoot area:       178 cm2           shoot area:       130 cm2           shoot height:       23 cm           shoot height:       15 cm           root area:       178 cm2           root area:       130 cm2           root height:       5 cm           root height:       5 cm Temperature     Method:       active control using thermoelectric coolers     Range:       19 - 45 oC     Accuracy:       ± 0.5 oC from the set point     Uniformity:       ± 1 oC within plant canopy plane Humidity     Method:       active control using Astropore® technology     Range:       55 - 95 % RH     Accuracy:       ± 3 % RH from the set point     Uniformity:       ± 5 % RH within plant canopy plane Lighting     Method:       high intensity red (670 nm) and blue (470 nm) light emitting diodes (LEDs)     Intensity:       0 - 450 μmol/m2/s for red and 0 - 50 μmol/m2/s for blue, measured at bottom of the chamber     Control:       photon flux programmably controlled with ± 5% of setpoint     Uniformity:       ± 10 % within plane, 10 cm from the light source Water/Nutrient Delivery     Method:       capillary mass transfer through rooting matrix via porous materials     Control:       solution pH range 4.5 - 7.5 ±0.2 Atmosphere Composition     CO2:       300 - 2000 ppm ± 50 ppm or ± 5% of the setpoint     Ethylene:       < 50 ppb by photocatalytic oxidation Data/Video Downlink     Data:       RS-232 interface     Video:       NTSC interface ASC-GC Flight History Shuttle Missions: STS-50 (1992) STS-57 (1993) STS-60 (1993) STS-63 (1994) STS-73 (1995) STS-95 (1998) STS-107 (2002) Space Station Missions: MIR (1998) Web site feedback, questions or accessibility issues: Webmaster Last modified: July 20, 2007