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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).

Conceptual designs for a space suit Personal Life Support Subsystem (PLSS) were developed and assessed to determine if upgrading the system using new, emerging, or projected technologies to fulfill basic functions would result in mass, volume, or performance improvements. Technologies were identified to satisfy each of the functions of the PLSS in three environments (zero-g, Lunar, and Martian) and in three time frames (2006, 2010, and 2020). The viability of candidate technologies was evaluated using evaluation criteria such as safety, technology readiness, and reliability. System concepts (schematics) were developed for combinations of time frame and environment by assigning specific technologies to each of four key functions of the PLSS -- oxygen supply, waste removal, thermal control, and power. The PLSS concepts were evaluated using the ExtraVehicular Activity System Sizing Analysis Tool, software created by NASA to analyze integrated system mass, volume, power and thermal loads.

Early development of concepts for space structures up to 1000 meters in size was initiated in the early 1960's and carried through the 1970's. The enabling technologies were self-deployables, on-orbit assembly, and on-orbit manufacturing. Because of the lack of interest due to the astronomical cost associated with advancing the on-orbit assembly and manufacturing technologies, only self-deployable concepts were subsequently pursued. However, for over 50 years, potential users of deployable antennas for radar, radiometers, planar arrays, VLBF and others, are still interested and constantly revising the requirements for larger and higher precision structures. This trend persists today. An excellent example of this trend is the current DARPA/SPO ISAT Program that applies self-deployable structures technology to a 300 meter long active planar array radar antenna. This ongoing program has created a rare opportunity for innovative advancement of state-of-the-art concepts.

The products of thermodegradation of fluorocarbon polymers (found in electrical insulation) will be toxic to space habitat crews, and the monitoring and detection of such contaminants are important to space environmental health. Experiments are therefore being performed on the thermodegradation of a liquid perfluoroalkane mixture (consisting of perfluorohexanes, C6F14, and −5% perfluoropentane, C5F12), similar in structure to polytetrafluoroethylene (PTFE - Teflon), in atmospheres of varying oxygen concentration. PTFE is a common material used on space vehicles for insulation of wires. When PTFE is thermally degraded, such as from the overheating of a wire and subsequent smoldering of the insulation, it may produce toxic compounds ranging from carbonyl fluoride and hydrogen fluoride through perfluorinated aromatic compounds to ultrafine particles.

An event in which electronic insulation consisting of polytetrafluoroethylene undergoes thermodegradation on the Space Station Freedom is considered experimentally and theoretically from the initial chemistry and convective transport through pulmonary deposition in humans. The low-gravity environment impacts various stages of event simulation. Vapor-phase and particulate thermodegradation products were considered as potential spacecraft contaminants. A potential pathway for the production of ultrafine particles was identified. Different approaches to the simulation and prediction of contaminant transport were studied and used to predict the distribution of generic vapor-phase products in a Space Station model.

This paper reports on the approach and progress to refine the estimates of the Mars surface photosynthetically active radiation (PAR) on a global scale that is averaged over a longer time period. While the PAR on Mars has been evaluated previously, the results have been limited in scope either temporally or spatially, such as only at a particular landing site or only over the time span of a few months. Understanding the availability of PAR is important in evaluating the practicality of using greenhouses and/or solar irradiance collectors for growing crops during manned missions to the Martian surface. Until surface investigations can be performed, computational modeling of the surface PAR can help to refine site selection and evaluation of engineering approaches and indicate the most favorable location at which to operate a greenhouse. The proposed approach is to combine multispectral irradiance models with global atmospheric opacity models developed from multiyear observations.

An eventual return to colonize the Moon or the launch of a human exploration mission to Mars will drive the need for developing novel surface Extravehicular Activity (EVA) technologies as well as require new operational and planning techniques. These advances are necessary to enable safe EVA access to the planetary surface locales that are most likely to yield exciting scientific knowledge, such as in the sedimentary deposit regions recently found on Mars or within and around large craters formed from asteroid collisions; as these represent the areas thought most likely to contain fossilized evidence of life or geological information pertaining to the origins and age of the planets. These sites, while rich in potential for scientific discovery, also introduce challenging terrain for exploration by surface EVA teams.

The Biological Wastewater Processor Experiment Definition team is performing the preparatory ground research required to define and design a mature space flight experiment. One of the major outcomes from this work will be a unit-gravity prototype design of the infrastructure required to support scientific investigations related to microgravity wastewater bioprocessing. It is envisioned that this infrastructure will accommodate the testing of multiple bioprocessor design concepts in parallel as supplied by NASA, small business innovative research (SBIR), academia, and industry. In addition, a systematic design process to identify how and what to include in the space flight experiment was used.

Aeroponics is the process of growing plants in an air/mist environment without the use of soil or an aggregate media. Aeroponics has contributed to advances in several areas of study including root morphology, nutrient uptake, drought and flood stress, and responses to variations in oxygen and/or carbon dioxide root zone concentrations. The adaptability of the aeroponic process that has benefited researchers makes its application to spaceflight plant growth systems appealing. Greater control of growth parameters permits a greater range of crop performance throttling and the elimination of aggregates or common growth substrates lowers system mass, lessens disease propagation between plants, and can decrease the required crew time for both planting and harvesting.

Spaceflight plant growth chambers require an atmosphere control system to maintain adequate levels of carbon dioxide and oxygen, as well as to limit trace gas components, for optimum or reproducible scientific performance. Recent atmosphere control anomalies of a spaceflight plant chamber, resulting in unstable CO2 control, have been analyzed. An activated carbon filter, designed to absorb trace gas contaminants, has proven detrimental to the atmosphere control system due to its large buffer capacity for CO2. The latest plant chamber redesign addresses the control anomalies and introduces a new approach to atmosphere control (low leakage rate chamber, regenerative control of CO2, O2, and ethylene).