Conditions Of Outer Space Research Articles

Some problems in space simulation chamber design

In presenting this paper the authors have emphasized the various factors which influence the design of space chambers and especially those which present particular problems and on which the success of the design depends. A discussion on vacuum requirements and the effect of outgassing from various materials introduces the reader to one of the more important design criteria. This is followed by an analysis of the absorption characteristics of a refrigerated coil and its relation to outer space conditions. The effect of frost layer on the absorptivity factor is demonstrated from experimental data and the advantages of cryopumping are outlined. An appraisal of factors influencing the design of the vessel and its geometry is made, particularly with regard to the mode of absorption coil and its attendant refrigeration system. The process of evaporation is explained together with factors which influence pressure drop in pipes, temperature gradients and distribution of refrigerant. A closed cycle refrigeration system is discussed in detail. The principles of achieving solar simulation are given and comparison between xenon arc and carbon arc sources. Various optical systems are explained.

Space Work

Caltech's Jet Propulsion Laboratory has awarded a $4‐million contract to Consolidated Vacuum Corporation, a subsidiary of Bell & Howell/Consolidated Electrodynamics Corp. of Rochester, N.Y., for the design and construction of a space‐environmental facility capable of simulating solar radiation as well as the atmospheric conditions of outer space. The simulator is described as a stainless steel tower 80 feet high and 27 feet in diameter, with a vacuum chamber in the lower portion large enough to accommodate full‐scale space vehicles. The upper portion of the tower will house the solar‐simulation unit.

Experimental investigations of plasma accelerators for space vehicle guidance and propulsion

A description is given of experimental studies concerning the possible application of a plasma accelerating device as a small thrust electric drive for space propulsion and attitude control. The particular laboratory model discussed employs a capacitor discharge across the gap between two electrodes to create a highly ionized but electrically neutral plasma which is electromagnetically accelerated into a chamber in which an attempt has been made to simulate the pressure conditions of outer space. A novel valve has been devised which serves the dual purpose of introducing the minute amounts of propellant required while obviating the need for external switching of the discharge. As a result of this development, a considerable improvement in the efficiency of energy conversion of earlier models has been affected. Specific impulses obtained with the T-tube accelerator have been in the range of 1000–20,000 sec, with calculated efficiency of conversion of stored electrical energy to mechanical energy as high as 60 per cent. Although the measurements discussed are of a preliminary nature, it is believed that they clearly demonstrate that more detailed and advanced research into plasma acceleration problems is fully justified.

Power sources for satellites and space vehicles

Abstract Power sources for satellites and space vehicles must be small, light, rugged, reliable for long operational life under the severe environment conditions of outer space. The environment generated by the operation of the power source must also be compatible with the operation of the instrumentation carried by the space vehicle. Chemical batteries, solar energy converters, and nuclear energy devices appear as the most suitable energy systems. Chemical batteries, having proven their practical capabilities in several earth satellites, provide reliable power for relatively short life and low-power requirements. Solar energy converters with or without storage devices, which also have already practically demonstrated their capabilities in several satellites, will offer high power for operation over at least several years. Nuclear devices under development promise characteristics which may ultimately surpass the capabilities of solar energy converters although for some time both systems may stay in close competition.