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A new type of ozone contactor, called the SVI-DT (sidestream venturi injection with downflow tube) contactor, was evaluated at pilot scale and compared with the performance of a traditional countercurrent flow, fine-bubble diffusion contactor. The specially designed downflow tube, equipped with one or more pressurized sidestream venturi injectors and installed inside an ozone reactor, facilitated the dissolution of ozone into water. The results showed that the SVI-DT contactor achieved high mass transfer rates and outperformed the fine-bubble diffusion contactor in removing color and yielding higher and longer-lasting dissolved ozone residuals. The hydraulic behavior of the new contactor was also evaluated, and operating limits were established for maintaining stable two-phase flow conditions in the downflow tube.

The use of lunar-derived liquid oxygen with hydrogen for robust manned explorations beyond earth is discussed. The propellant mixture ratio for optimal performance is near the current design point of r = 6. The results of NASA-sponsored studies of missions using cryogenic bipropellant H2-O2 for most functions reveal the potential benefits from a propellant terminal in cis-lunar space. The main propulsion technologies associated with Mars mission case studies include: in-space fluid transfer, zero-g ignition, oxygen-enriched propellant mixtures, throttling of main engines, and H2-O2 based auxiliary propulsion.

T rate of industrial development in space is largely dependent on the cost of transportation to, through, and from space and the cost of electrical power in space. The technological and economical impact of a large central-power station in Earth orbit on the cost and performance of future spacecraft and their orbital-transfer systems has been examined. Analysis of the cost effectiveness of meeting Earth-orbiting spacecraft electrical power demands from a central-power station indicates that this application cannot justify the investment required for the central station. However, laser-thermal and laser-electric propulsion systems powered from a central-power station promise major cost savings when compared to orbital-transfer vehicles using advanced, conventional, chemical, and solar-electric propulsion—at least within the bounds of the assumptions made.