4. PROGRAMS, MISSIONS, AND PAYLOADS

Cosmos 1129

MISSION PROFILE: Cosmos 1129

Mission Duration: 18.5 days

Date: September 25-October 14, 1979

Life Sciences Research Objectives
To study the effects of space flight on biological systems
To study mammalian reproductive processes and avian embryogenesis in space
To measure radiation levels in space

Life Sciences Investigations
Musculoskeletal (C1129- 3.1, 3.2, 3.3, 3.4, 3.5, 4, 5, 6.1, 6.2, 7)
Plant Biology (C1129- 8.1, 8.2, 9)
Radiation/Environmental Health (C1129- 10)
Regulatory Physiology (C1129- 11, 12, 13)

Organisms Studied
Rattus norvegicus (rat)
Coturnix coturnix (Japanese quail)
Daucus carota (carrot)

Flight Hardware
Carrot Tissue Containers
Radiation Detectors:Plastic Nuclear Track Detectors
Radiation Detectors: Cosmos 1129 Radiation Detector Packets
Radiation Detectors: Cosmos 1129 Corner Stacks
Temperature Recording System

The Cosmos 1129 satellite was launched on September 25, 1979 and recovered in Central Asia on October 14, 1979. The spacecraft carried biological and radiation physics experiment packages from Czechoslovakia, France, Hungary, Poland, Romania, the German Democratic Republic, the U.S., and the U.S.S.R.

     The U.S. investigations onboard included a radiation physics experiment and several biological experiments using rats, quail embryos, and plants.

U.S. Life Sciences Research Objectives

As it was for all Cosmos missions, the principal objective of Cosmos 1129 was to study the effects of space flight on biological systems, with a particular focus on the biomedical problems observed in men and animals during space flight. A concerted effort was made to maximize the science return from the mission. To this end, virtually every organ and tissue from the rat specimens flown was examined by investigators. Space flight effects on bone and muscle were examined in a series of studies on rats. Rats were also used in an attempt to study mammalian reproductive processes in space. A study of avian embryogenesis was carried out for the first time on this mission. Microgravity effects on plants were investigated using carrot tissue. The radiation exposure of the spacecraft and its contents was measured in a radiation dosimetry experiment.

U.S. Life Sciences Payload

     Organisms

     Thirty male specific pathogen free rats (Rattus norvegicus) of the Wistar strain were flown onboard and served as experimental subjects for a wide variety of physiological studies. When the experiments began, the rats were about 85 days old and weighed, on average, 300 grams. The flight rats were divided into five groups for experimental purposes. They were euthanized 7 to 11 hours after landing (group 1), 32 to 37 hours after landing (group 5), 6 days postflight (groups 2 and 3), or 29 days postflight (group 4).

     Seven more Wistar rats were flown as part of the rat embryology experiment. Five of these were females weighing about 340 grams at launch and two were males weighing about 260 grams (Fig. 4-38).

     Fertilized Japanese quail (Coturnix coturnix) eggs were flown to evaluate the effects of space flight on avian embryological development.

     The effects of space flight on the rate of cellular metabolism were assessed by studying the growth of crown gall tumors in carrots (Daucus carota). Carrot cell cultures were used to determine if growth and development of plants were affected by space flight.

     Hardware

     U.S.S.R.-Provided

     The 30 rats used in the physiology studies were kept in individual cages as on the Cosmos 782 and 936 flights.

     The spacecraft also contained a rodent mating chamber for housing the seven rats used in the rodent embryology study (Fig. 4-38). At launch, the chamber was partitioned into two sections, which separated the two male rats from the five females. On the second day of flight, two doors in the partition were opened, allowing the rats to mingle. There were eight feeding stations within the chamber. Ten-gram aliquots of the paste diet were presented at each station at six-hour intervals. Light was provided on a 12:12 light and dark cycle.

Figure 4-38: The rodent mating chamber: (a) female chamber; (b) feeding station; (c) remotely activated partition door; and (d) male chamber.

     The quail egg incubator was an insulated chamber suspended from the mounting framework by heavy-duty elastic shock cords (Fig. 4-39). Within the chamber, the eggs were held between two perforated rubber strips located on the inner and outer steel rings. The chamber contained 5 egg rings, each bearing 12 eggs. When activated, the incubator could maintain a temperature of 37°C and a relative humidity of about 70 percent. The egg rings could be rotated within the incubator preflight and during the synchronous control experiment. In-flight rotation was not thought to be necessary.Total gross body movement of the flight and synchronous control animals was monitored on odd-numbered days during the flight period (Fig. 4-40). Body temperatures of the group 4 animals in flight and synchronous control groups were obtained on even-numbered days. The light and dark cycle of group 4 rats was reversed on day 10 by subjecting the animals to 24 hours of continuous darkness. These rats were maintained at the reversed cycle after flight. The reversal was carried out as part of a study to determine space flight effects on the animals' circadian rhythms and on their ability to adapt to an altered day and night cycle.

     Egg rings were rotated continuously to simulate microgravity conditions during the synchronous control experiment.

Figure 4-39: The quail egg incubator: (a) framework; (b) elastic shock cords; and (c) egg ring.

     U.S.-Provided

     For the carrot tumor growth experiment, cross sections of carrot were inoculated with suspensions of the bacterium Agrobacterium tumefaciens. Each of the two flight canisters contained a stack of four dishes, with four inoculated carrot disks in each dish. A synchronous ground control experiment was conducted using similar canisters located in a spacecraft mock-up. Other ground control experiments were conducted using canisters oriented vertically or horizontally with respect to gravity, or rotated either vertically or horizontally on clinostats.

     As on Cosmos 782, carrot cells and somatic embryos, respectively, were placed in agar culture medium in plastic petri dishes. The dishes were loaded into acrylic canisters and covered with aluminum end-caps. Two canisters were used in the flight experiment, and two in a synchronous ground control experiment that was conducted in simulated flight conditions. Two additional canisters were used in a stationary ground control experiment in which there was no flight simulation.

     Dosimetry packages were placed in two different locations. Stacks of plastic nuclear track detectors measured high-LET particles. Fission-foil detectors were used for neutron measurements. Thermoluminescent detectors measured total radiation doses from charged particles and gamma rays.

Operations

     Two different types of ground control studies were performed to aid in interpreting flight studies. During the synchronous control study, the in-flight environment of the spacecraft was simulated as closely as possible. The study was initiated five days after launch and conducted in a spacecraft mock-up. Specimens were housed in mock-ups of flight hardware. At the start of the study, the specimens were subjected to launch stresses including noise, vibration, and acceleration. Re-entry stresses were applied after the study was completed. Food, water, lighting, temperature, humidity, and airflow closely approximated in-flight conditions.

     The vivarium control study was conducted to provide data on minimally stressed rat specimens. Rats in groups 1, 2, 3, and 5 were housed in standard vivarium cages during the flight period. During the postflight period, they were kept in the same cages except on days 3, 8, and 13, when they were transferred to special metabolic cages for 36 hours at a time. Each animal received 40 grams of the flight paste diet once a day during the flight period, and 45 grams during the postflight period.

     During the preflight period, candidate animal subjects were group housed in a vivarium. Flight and control groups of animals were similarly treated. The pellet/seed diet was switched to the flight paste diet two weeks before fight. General animal health was assessed in daily examinations. Healthy animals for the flight and control groups were selected several days before launch.

     Total gross body movement of the flight and synchronous control animals was monitored on odd-numbered days during the flight period (Fig. 4-40). Body temperatures of the group 4 animals in flight and synchronous control groups were obtained on even-numbered days. The light and dark cycle of group 4 rats was reversed on day 10 by subjecting the animals to 24 hours of continuous darkness. These rats were maintained at the reversed cycle after flight. The reversal was carried out as part of a study to determine space flight effects on the animals' circadian rhythms and on their ability to adapt to an altered day and night cycle.

     On day two of flight, the partition separating male and female rats in the rodent mating chamber was opened and the rats were allowed to intermingle throughout the remainder of the flight.

     The quail egg incubator was activated on the seventh day of the mission, allowing the temperature and humidity to be raised to 37°C and about 80 percent, respectively. These environmental conditions are appropriate for initiating embryo development in fertilized eggs. Unfortunately, the humidity control system failed on day 13 of the mission, causing the relative humidity to drop to cabin ambient level. This had detrimental effects on the developing quail embryos.

     Within several hours of landing, a field laboratory had been set up at the Biosatellite recovery site. Autopsies were performed there on the group 1 rats. The remaining specimens were transported to Moscow. During the readaptation period that followed, the flight rats were subjected to a variety of tests. Following these operations, specimens were shipped to U.S. laboratories in specially designed containers. These containers could maintain the temperatures required to ensure specimen integrity.

*Amount actually consumed may be less. Table 4-7: Cosmos 1129 flight and control rat experiments.

Results

     Rodents

     Flight rats were noted to be in good condition postflight. Postflight analyses indicated that changes had occurred in rat bone during space flight. Among these were decreased bone formation, decreased bone volume, density and strength, increased fat content of bone marrow, and alterations in osteoblasts and osteoclasts.

     Space flight effects on rat muscle included decreased muscle fiber size and a change in the proportion of fiber types. Metabolic effects and a change in body composition were also noted postflight.

     Although all rats in the flight and synchronous control groups were subsequently shown to be fertile, none of them gave birth as a result of mating that may have occurred during the flight phase of the experiments.

     Quail eggs

     Only one of the quail embryos survived. In that embryo, development seemed normal. In the other embryos, decreased humidity appeared to have resulted in dehydration and increased fragility of the shell.

     Plants

     No changes were noted in the growth and development of plant cells and embryos in space. The tumor growth studies indicated that gravity compensation provided by ground -based clinostat rotation did not equal microgravity.

     Radiation

     The radiation dosimetry experiment provided a comprehensive picture of the radiation experienced by the spacecraft and its contents.

Figure 4-40: In-flight events for the rat experiments: body temperature and movement during flight were measured on alternate days. The light and dark cycle was reversed on day nine.

Move to next section Cosmos 1514

Additional Reading

Heinrich, M.R. and K.A. Souza. U.S. Rat Experiments Flown on the Soviet Satellite Cosmos 1129. Final Reports. NASA TM-81289, August 1981.

Heinrich, M.R. and K.A. Souza. U.S. Plant and Radiation Dosimetry Experiments Flown on the Soviet Satellite Cosmos 1129. Final Reports. NASA TM-81288, 1981.

Keefe, J.R. Experiment K-33: Rat and Quail Ontogenesis. U.S. Experiments in the Soviet Satellite Cosmos 1129. NASA TM-81289, August 1981, pp. 325-362.