Research in space nutrition
Astronaut space nutrition, discussing Apollo mission short range nonregenerative mode, long range closed loop regenerative cycles and waste recycling
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Astronaut space nutrition, discussing Apollo mission short range nonregenerative mode, long range closed loop regenerative cycles and waste recycling
Design and construction of cryopump is reported that feeds from primary source to cool component up to 30 ft from source. Liquid oxygen or nitrogen is gravity fed through loop system to copper fibers enclosing component at room temperature where fluid boils, cools object, vaporizes and recycles through tubing loop.
An experimental system was developed for evaluation of the effects of aerodynamic heating and cooling, vacuum, and pressure loading on candidate insulation packages proposed for use on the space shuttle. The system includes a number of design features which facilitate rapid recycle times. This is necessary to efficiently conduct extensive thermal cycling tests on these insulation packages to determine their reuse capabilities. The heart of the system is a 26-inch graphite element radiant heater. A susceptor plate functions as a uniform-temperature intermediate radiating surface. The susceptor also forms the lid of an inert atmosphere enclosure which separates the heater from the oxidizing test atmosphere. In some tests the plate properly simulates the heating from an actual flight heat-shield panel. Although other materials were used at lower required test temperatures, 2500 F was routinely achieved using a coated columbium susceptor plate.
The function of the spermaceti organ of the sperm whale is studied using a model of its acoustic system. Suggested functions of the system include: (1) action as an acoustic resonating and sound focussing chamber to form and process burst-pulsed clicks; (2) use of nasal passages in forehead for repeated recycling of air for phonation during dives and to provide mirrors for sound reflection and signal processing; and (3) use of the entire system to allow sound signal production especially useful for long range echolocofion in the deep sea.
A 1/4-man solid electrolyte oxygen regeneration system, consisting of an electrolyzer, a carbon deposition reactor, and palladium membranes for separating hydrogen, was operated continuously in a 180-day test. Oxygen recovery from the carbon dioxide-water feed was 95%. One percent of the oxygen was lost to vacuum with the hydrogen off-gas. In a space cabin, the remaining 4% would have been recycled to the cabin and recovered. None of the electrolysis cells used in the 180-day test failed. Electrolysis power rose 20% during the test; the average power was 283.5 watts/man. Crew time was limited to 18 min/day of which 12 min/day was used for removing carbon. The success achieved in operating the system can be attributed to an extensive component development program, which is described. Stability of operation, ease of control, and flexibility in feed composition were demonstrated by the life test.
The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo solar wind composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or solar protons, stripping by cosmic ray or energetic solar alpha particles, recycling of solar wind He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.
The variable magnetic baffle described in this paper aids in control of electron flow from the hollow cathode plasma into the main discharge region by augmenting the fringe magnetic field which impedes this electron flow in conventionally baffled Kaufman thrusters. A passive, low loss, and automatic control device is obtained by using the discharge current to excite the control winding. Used in conjunction with typical thruster control loops, stable operation has been obtained over a 10:1 throttling range with a 30 cm thruster. Discharge ignition and overcurrent recycling is also facilitated through use of this device in a permanent magnet thruster.
The primordial gas out of which the Galaxy condensed may have been significantly enriched in heavy elements. A specific mechanism of enrichment is described, in which quasi-stellar sources eject enriched matter into the intergalactic medium. This matter is recycled through successive generations of these sources, and is progressively enriched. The enriched intergalactic matter is accreted by the protogalaxy and we find, for rates of mass ejection by quasi-stellar sources equal to about one solar mass per year in heavy elements, that this mechanism can account for the heavy-element abundances in the oldest Population II stars. Expressions are given for the degree of enrichment of the intergalactic gas as a function of redshift, and we show that our hypothesis implies that the present density of intergalactic gas must be at least a factor 3 larger than the mean density in galaxies at the present epoch.
Recyclable actuator does depend on valves for its operation. Palladium cathode tube in electrochemical cell is used to generate hydrogen by electrolysis. Hydrogen pressure generated inside tube causes expansion of bellows, which raises load. Bellows can be retracted by reversing electrical connections to cell electrodes.
Unit recovers 97% of water contained in pretreated waste water. Some factors are: cleansing agent prevents fouling of heat transfer surface by highly concentrated waste; absence of dynamic seals reduces required purge gas flow rate; and recycle loop maintains constant flushing process to carry cleansing agent across evaporation surface.
A systems engineering study is presented for a proposed lunar colony. The lunar colony was to grow from an existent, 12-man, earth-dependent lunar surface base and was to utilize lunar resources, becoming as earth-independent as possible. An in-depth treatment of some of the aspects of the lunar colony was given. We have found that the use of lunar resources is feasible for oxygen production (both for breathing and for space tug fuel), food production, and building materials. A program is outlined for recycling waste materials developed at the colony as well as a full program for growth and research activity of the colony to a level of 180 colonists. Recommendations for the lunar colony are given.
The experimental and theoretical investigations conducted during the period from September 1969 through September 1972 are reported which were directed toward obtaining information necessary to determine the feasibility of the full-scale nuclear light bulb engine, and of small-scale nuclear tests involving fissioning uranium plasmas in a unit cell installed in a driver reactor, such as the Nuclear Furnace. Emphasis was placed on development of RF simulations of conditions expected in nuclear tests in the Nuclear Furnace. The work included investigations of the following: (1) the fluid mechanics and containment characteristics of one-component and two-component vortex flows, both unheated and RF-induction heated; (2) heating of particle-seeded streams by thermal radiation from a dc arc to simulate propellant heating; (3) condensation and separation phenomena for metal-vapor/heated-gas mixtures to provide information for conceptual designs of components of fuel exhaust and recycle systems; (4) the characteristics of the radiant energy spectrum emitted from the fuel region, with emphasis on definition of fuel and buffer-gas region seed systems to reduce the ultraviolet radiation emitted from the nuclear fuel; and (5) the effects of nuclear radiation on the optical transmission characteristics of transparent materials.
A case study of knowledge contributions from the crew life support aspect of the manned space program is reported. The new information needed to be learned, the solutions developed, and the relation of new knowledge gained to earthly problems were investigated. Illustrations are given in the following categories: supplying atmosphere for spacecraft; providing carbon dioxide removal and recycling; providing contaminant control and removal; maintaining the body's thermal balance; protecting against the space hazards of decompression, radiation, and meteorites; minimizing fire and blast hazards; providing adequate light and conditions for adequate visual performance; providing mobility and work physiology; and providing adequate habitability.
The recycle, reuse, or reclamation of single cell protein from liquid and solid agricultural waste fibers by a fermentation process is reported. It is shown that cellulose comprises the bulk of the fibers at 50% to 55% of the dry weight of the refuse and that its biodegradability is of prime importance in the choice of a substrate. The application of sodium hydroxide followed by heat and pressure serves to de-polymerize and disrupt lignin structure while swelling the cellulose to increase water uptake and pore volume. Some of the lignin, hemi-celluloses, ash, and cellulose of the material is hydrolized and solubilized. Introduction of microorganisms to the substrate fibers mixed with nutrients produces continuous fermentation of cellulose for further protein extraction and purification.
A description is presented of a unique system for the sterilization and sterile repair of spacecraft and the results of a test program designed to assess the biological integrity and engineering reliability of the system. This trailer-mounted system, designated the model assembly sterilizer for testing (MAST), is capable of the dry-heat sterilization of spacecraft and/or components less than 2.3 meters in diameter at temperatures up to 433 K and the steam sterilization of components less than 0.724 meter in diameter. Sterile access to spacecraft is provided by two tunnel suits, called the bioisolator suit systems (BISS), which are contiguous with the walls of the sterilization chambers. The test program was designed primarily to verify the biological and engineering reliability of the MAST system by processing simulated space hardware. Each test cycle simulated the initial sterilization of a spacecraft, sterile repair of a failed component, removal of the spacecraft from the MAST for mating with the bus, and a sterile recycle repair.
The potential of certain cis-trans isomers and doped LiNbO3 for the holographic read/write/erase memory application was investigated. The cis-trans work involved the photochemical investigation of a number of potential materials as well as specific molecular engineering efforts on alpha-methyl stilbene and its derivatives. These efforts resulted in an increase in the change in index of refraction, and thereby, in potential recording utility, of an order of magnitude. The work on LiNbO3 was directed toward a preliminary investigation of the dynamics of the writing process. Several samples and a variety of writing conditions were investigated. An unexpected and as yet unexplained improvement in material behavior with continued recycling was observed. In addition, some effort was devoted to an analysis of the physical conditions under which several current theories of the optical damage process are valid.
The work is described accomplished in compiling information needed to establish the current water supply and waste water processing requirements for dwellings, and for developing a preliminary design for a waste water to potable water management system. Data generated was used in formulation of design criteria for the preliminary design of the waste water to potable water recycling system. The system as defined was sized for a group of 500 dwelling units. Study tasks summarized include: water consumption, nature of domestic water, consumer appliances for low water consumption, water quality monitoring, baseline concept, and current and projected costs.
A program to establish technology readiness of hydrogen-oxygen (H2-O2) auxiliary power units for use on board the space shuttle orbiter vehicle is discussed. Fundamental objectives include experimentally establishing an acceptable propellant flow control method, verification of combustor stability, and adequate thermal management. An initial APU configuration with recycled hydrogen flow has been studied and revised towards greater simplicity and scaling ease. The selected APU is a recuperated open-cycle, turbine-driven unit. Series flow of cryogenic hydrogen removes internally-generated heat and from the hydraulic system. Steady-state test of the combustor has been successful.