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Biomedical subjects

R G Lotz

Publications and source records attributed to R G Lotz.

8 recordsLinked to original sources
PubMed1972

Test of a life support system with Hirudo medicinalis in a sounding rocket.

Two Nike-Tomahawk rockets each carrying two Biosondes were launched from Wallops Island, Virginia, the first on 10 December 1970 and the second on 16 December 1970. The primary objective of both flights was to test the Biosonde life support system under a near weightless environment and secondarily to subject the Hirudo medicinalis to the combined stresses of a rocket flight. The duration of the weightless environment was approximately 6.5 minutes. Data obtained during the flight by telemetry was used to ascertain the operation of the system and the movements of the leeches during flight. Based on the information obtained, it has been concluded that the operation of the Biosondes during the flight was similar to that observed in the laboratory. The experiment and equipment are described briefly and the flight results presented.

Air Conditioning↗
PubMed1969

The problem of sterilizing a life-support system in biosatellite experiments over one year.

Special efforts are necessary to sterilize the life-support system for experimental animals in biosatellite experiments over one year. The energy requirements needed are relatively high and the energy which is available in biosatellites at the present time is a limiting factor, particularly in long-term experiments. It is shown that these difficulties are overcome by the selection of an appropriate experimental animal. Thus, it was possible to prepare a long-term satellite experiment.

Animals↗
PubMed1969

Oxygen supply and carbon dioxide absorption in long-term life-support systems.

Long-term experiments with animals in space require a life-support system that provides optimal conditions of life at lowest energy demand. Experimental studies of different physicochemical and biological systems are compared. While such experiments are limited by energy requirements, it is possible to choose a certain system by comparing the exact energy balances of the different ecological systems.

Absorption↗
PubMed1968

A life support system for satellite experiments over one year.

The study of organisms in satellites over a period of a year or longer has failed due, primarily, to the high technical efforts in order to keep even low organisms alive. A new life support system is reported which enables the performance of experiments over a long period of time with an approximate animal (Hirudo medicinalis). The system has a total weight of 3 kg and a current consumption of 4 watts.

Animals↗
PubMedDate not supplied

Long-term biological investigations in space.

Missions in space within the next two decades will be of longer duration than those carried out up to the present time, and the effects of such long-term flights on biological organisms are unknown. Results of biological experiments that have been performed to date cannot be extrapolated to results in future flights because of the unknown influence of adaptation over a long period of time. Prior experiments with Axolotl, fishes, and vertebrates by our research team (in part with sounding rockets) showed that these specimens did not appear to be suitable for long-term missions on which minimization of expense, technique, and energy is required. Subsequent investigations have shown the suitability of the leech (Hirudo medicinalis), which consumes blood of mammals up to ten times its own weight (1 g) and can live more than 2 years without further food supply. Emphasis in the experiments with Hirudo medicinalis is placed on metabolic rhythm and motility. Resorption and diffusion in tissue, development, and growth under long-term effects of cosmic proton radiation and zero-gravity are other focal points. The constancy of cellular life in the mature animals is a point in favor of these specimens. We have also taken into account the synergistic effects of the space environment on the problems just mentioned. The life-support system constructed for the leech has been tested successfully in four sounding rocket flights and, on that basis, has been prepared for a long-term mission. Long-term investigations out of the terrestrial biosphere will provide us with information concerning the degree of adaptation of certain physiological and biochemical functions and as to what extent biological readjustment or repair processes can occur under the specific stress conditions of space flight.

Animals↗