Space vehicle applications

H2 is preferable for a closed environment such as space vehicle application. There are sources of H2-rich gases, such as an off-gas at a chemical plant, that require only fuel cleaning. Fuel flexibility is not applicable in either case. 

FIGURE 6.4.2 Schematic atmosphere control system for space vehicle application. (From Jones, W.L. and Ingelfinger, A.L., Atmosphere control, in Bioastronautics Data Book, J.F. Parker Jr. and V.R. West, eds., NASA, SP-3006 U.S. Government Printing Office, Washington, DC, 1973, pp. 807-845. With permission.)... 

Because of this low bulk density and inherently low heat capacity of the materials used in the insulating system, the application of NRC insulation to cryogenic equipment or apparatus offers not only an efficient reduction of the heat leak, but also a remarkably low additional heat capacity, which results in drastic decrease of cool-down losses. At the same time, the low heat capacity makes it possible to reach thermal equilibrium in much shorter time than is possible with other types of multilayer insulations with bulk weights three to six times higher. This is of great importance in the consideration of air-borne or space-vehicle applications. The low thermal capacity of the insulation makes feasible and economically justifiable the use of this insulation in liquid-gas transfer lines. 

The use of cryogenic propellants in current and proposed missiles and space vehicles has stimulated interest in the low-temperature properties of cold-worked 301 stainless steel for a variety of structural applications. This alloy is of particular interest because of the favorable combination of properties which it exhibits over a wide range of temperature which suit it for use in missile and space vehicle applications. These favorable properties include the retention of toughness at low temperature, good strength-to-density characteristics, excellent weldability, and excellent corrosion resistance. 

The separation of helium-rich natural gas provides most of the helium used in the U.S. The Bureau of Mines has acted as the agent for the Federal government under the Helium Act of 1947 for the recovery, distribution, and sale of helium because of its importance in missile and space-vehicle applications. This recovery has been augmented in more recent times by a number of industrial process plants. 

Stress-corrosion cracking occurs in titanium alloys in a number of environments, although the number of failures that have occurred under service conditions is very small. Because of the widespread use of titanium alloys in aeroplanes and space vehicles and their increasing use in marine applications it is important that the possibilities of service failures should be removed. As a result a considerable and increasing amount of work has been done on this subject over the last decade as indicated in a recent extensive survey. ... 

Plastics have a unique contribution to make in exploring new environments. Their applications in space vehicles are well known and are generally of a mechanical nature. Plastics are used extensively in equipment for exploring under the sea. One unique application for plastics used in the sea environment and which is important in other areas that range from packaging to space is in filtering... 

Advanced ceramics have a wide range of application (Figure 5.3). In many cases, they do not constitute a final product in themselves, but are assembled into components critical to the successful performance of some other complex system. Commercial applications of advanced ceramics can be seen in cutting tools, engine nozzles, components of turbines and turbochargers, tiles for space vehicles, cylinders to store atomic and chemical waste, gas and oil drilling valves, motor plates and shields, and electrodes for corrosive hquids. 

The major applications for fuel cells are as stationary electric power plants, including cogeneration units as motive power for vehicles and as on-board electric power for space vehicles or other closed environments. Derivative applications will be summarized. 

The Alkaline Fuel Cell (AFC) was one of the first modern fuel cells to be developed, beginning in 1960. The application at that time was to provide on-board electric power for the Apollo space vehicle. Desirable attributes of the AFC include its excellent performance on hydrogen (H2) and oxygen (O2) compared to other candidate fuel cells due to its active O2 electrode kinetics and its flexibility to use a wide range of electrocatalysts, an attribute which provides development flexibility. 

ABS (30% acrylonitrile, 20% butadiene, and 50% styrene) is a tough plastic with outstanding mechanical properties ABS is one of the few plastics that combines both toughness and hardness. So the applications include ballpoint pen shells, fishing boxes, extruded pipes, and space vehicle mechanical parts. There s more than 20 pounds of ABS molded parts in an automobile. 

Teflon was introduced to the public in 1960 when the first Teflon-coated muffin pans and frying pans were sold. Like many new materials, problems were encountered. Bonding to the surfaces was uncertain at first. Eventually the bonding problem was solved. Teflon is now used for many other applications including acting as a biomedical material in artificial corneas, substitute bones for nose, skull, hip, nose, and knees ear parts, heart valves, tendons, sutures, dentures, and artificial tracheas. It has also been used in the nose cones and heat shield for space vehicles and for their fuel tanks. 

Such sheath retains the heat, noise, and detonating products, and permits the cords to be used in critical applications, eg the explosive sepn of missile stages of space vehicle components) Ad 167) A. Lachs,... 

Due to their unique properties, a large number of groups all over the world are working in the area of CNTs for diverse applications and the most important are development and fabrication of sensors and thermal protection for atmospheric re-entry of space vehicles. Gas and glucose sensors based on CNTs have been developed. Some American researchers have recently claimed that they have developed CNT-based sensors for the detection of chemical warfare agents [80]. 

T he unique properties of polymers make them desirable for use in A space vehicles and apparatus, as well as in nuclear reactor components and auxiliaries. In both applications intense radiation fields can be encountered routinely or occasionally. Several books have been written about the effects of radiation on polymers (I, 2, 4, 5) in general, the effects of high intensity radiation have been measured by exposing the polymer to a given amount of radiation followed by testing of properties later, outside the radiation field. 

Zinc-silver oxide reserve batteries have application as power sources for various systems in manned and unmanned space vehicles. 

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