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LoTEC© is a passive thermal carrier designed to maintain the temperature of biological samples for ten days or more for transport to and from the International Space Station (ISS) without the need of external power. LoTEC© relies on a combination of high thermal resistance insulation and high energy density storage phase change materials. The initial capability of LoTEC© encompasses several temperature ranges (e.g. 36 to 40C, 18 to 22C, 0 to 4C, and - 16 to -20C). LoTEC© fits into a standard mid-deck locker or an Express Rack locker; this facilitates easy transfer between the shuttle and the ISS. Thermal analysis modeling and laboratory test results are presented that characterize the performance of LoTEC© and the planned PCM materials.

Spaceflight life sciences research typically requires accurately controlled thermal environments to help isolate the effects of gravity on the development of living organisms or biochemical reactions. Given the power, mass and volume constraints of spaceflight experimental hardware, highly efficient temperature control is necessary to provide scientists with adequate tools for their research. The main focus is on 3 incubators, designed by the authors, for commercial space biotechnology research. While the simplest incubator allows for highly accurate temperature control above ambient only, the more sophisticated units use temperature-controlled liquid circulation systems for above and below ambient temperature control. The latest design variation provides eight individually controlled sample containers, where temperatures can be maintained constant or profiled for automated experiment initiation and termination, or preservation of samples on orbit.

Technology for microgravity plant growth has matured to a level which allows detailed gravitational plant biology and commercial plant biotechnology studies. Consequently, plants have been shown to adapt to the space flight environment, which validates their use in advanced life support applications. However, the volume available for plant growth inside pressurized modules is severely constrained, both in present and future spacecraft. Furthermore, the required power and heat rejection associated with the artificial lighting on existing systems, and the resulting weight and volume increases, affect the viability of these systems for life support. The Autonomous Garden Pod (AG-Pod), an inflatable module specifically for plants, resides outside the habitable modules and uses passive solar illumination. It’s based on existing technologies including flight-proven plant growth subsystems, commercial satellite thermal systems, and off-the-shelf inflatable technology.

The Plant Generic BioProcessing Apparatus (PGBA), a plant growth facility developed for commercial space biotechnology research, has flown successfully on 3 spaceflight missions for 4, 10 and 16 days. The environmental control systems of this plant growth chamber (28 liter/0.075 m2) provide atmospheric, thermal, and humidity control, as well as lighting and nutrient supply. Typical performance profiles of water transpiration and dehumidification, carbon dioxide absorption (photosynthesis) and respiration rates in the PGBA unit (on orbit and ground) are presented. Data were collected on single and mixed crops. Design options and considerations for the different sub-systems are compared with those of similar hardware.

PGBA, a plant growth facility developed for commercial space biotechnology research, successfully grew a total of 50 plants (6 species) during 10 days aboard the Space Shuttle Endeavor (STS-77), and has reflown aboard the Space Shuttle Columbia (STS-83 for 4 days and STS-94 for 16 days) with 55 plants and 10 species. The PGBA life support system provides atmospheric, thermal, and humidity control as well as lighting and nutrient supply in a 33 liter microgravity plant growth chamber. The atmosphere treatment system removes ethylene and other hydrocarbons, actively controls CO2 replenishment, and provides passive O2 control. Temperature and humidity are actively controlled.

P-MASS, the Plant-Module for Autonomous Space Support, is designed to support and provide life support for a variety of plants, algae and bacteria in low earth orbit during the maiden flight of COMET-1. The first launch is scheduled for early 1993. With a nominal mission duration of 30 days in microgravity, P-MASS will bridge the gap between the shorter duration experiments possible onboard the NSTS Space Shuttle (approximately 14 days) and the future Space Station Freedom for space biology applications. Environmental data and video images are collected, stored onboard and downlinked daily. In addition, the payload and all specimens will be returned for ground analysis with the recovery system (reentry capsule). P-MASS is designed within a payload envelope of 0.28 x 0.22 x 0.32 m (19.71) and a mass of approximately 20 kg. A total of 115 Watt electric power is available continuously for the Plant-Module (60 W lighting, 40 Watt cooling, 15 W housekeeping).

Tail-suspension of rats has been shown to cause loss of bone mass similar to that experienced by humans in microgravity. We have applied tail-suspension to mice to characterize bone, nervous system and muscle changes that occur and evaluate the use of magnetic fields to obviate these changes. Results have shown that femurs and tibiae of tail-suspended mice undergo significant decreases in dry weight, stiffness and strength. Immersion of mice in specific oscillating magnetic fields can reduce or eliminate these degenerative changes. Results have also shown that tail-suspended animals undergo changes in spinal cord function similar to changes previously observed in animals with damaged sciatic nerves. These changes include decreases in the uptake of GABA (an inhibitory neurotransmitter) into a purified fraction of synaptic nerve endings and changes in electrical responses recorded in an isolated spinal cord preparation.