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A cage module system supports the animal cages, air ducts through them, provides light and watering lixits within each cage and electronically connects the cages to power and data systems. Modules also contain temperature and humidity sensors. The modules are designed to support cages specific to an animal species, and are interchangeable in that they require the same rack space and interface in the same manner with all RAHF subsystems. Any cage insert can be removed without disturbing the remaining specimens. Each cage is large enough to allow speci- mens unrestricted movement and is designed to ensure the specimen's physical safety.
Rodent Cage Modules: Rodent cages are designed with a polycarbonate window in the partition between the two compartments so the crew can view both front and back rats by opening the cage drawer. Cage tops are hinged to access the animals sequentially and both had a hole large enough for the animal to reach the lixit valve installed in the air plenum above the cage to avoid disconnecting the plumbing on cage removal.
Rodent Feeder: Rodent food is supplied ad libitum in the form of a compressed diet bar. Rodent food is molded in rectangular bars which mount in a spring-loaded, side-mounted bar feeder. The bars are driven against a stop in such a way that the food bar is advanced as the rat consumes food, triggering a microswitch and a counter that records the number of clicks and, therefore, the amount of food bar remaining. Food bars can be changed by crewmembers through the feeder cassette without removing animals from the cage.
Waste Management System: The waste management system attaches to the lower part of each drawer through a slide arrangement beneath the floor of the cages. Access through a door on the drawer front face permits changing of the waste tray for missions of more than ten days duration. In microgravity, air at a velocity of 9.2 m/min flows from the top of the cage to the bottom and through the waste collection system. Aerodynamic drag on the waste products transports the liquid and solid matter to the collection system. A heat-felted fiberglass pad, 0.5 inch thick, is impregnated with phosphoric acid for absorption of urine and bacterial growth control. Odor control is accomplished by means of a phosphoric acid-treated activated charcoal bed, 0.25 inches thick. Because the Spacelab long-axis is vertical during launch, the RAHF is on its side (horizontal) during this time. The RAHF is installed only on the port side of the Spacelab to orient the cage waste trays properly. In this position, animal cages are designed with the waste tray down in the 1 g direction to capture animal wastes during prelaunch and launch. During orbit, the normal airflow through the cage moves wastes into the waste trays. On landing, cages are oriented 90° from launch so that the 1 g vector is through the cage wall for a short period of time, prior to cage removal.
Dimensions: 10.5 x 11.5 x 28 cm (compartment)
Weight: Unknown
Power: Unknown
Capacity: One 400 g rodent/compartment
Waste Control: Removable waste trays with charcoal (0.25 in) and absorbent wick (0.5 in) filters
Internal Activity Monitor: Reflection of 920 nm light beam
•Callahan, P.X., et al: Ames Research Center Life Sciences Payload Project for Spacelab Mission 3. SAE Technical Paper Series 831094, July 1983.
•Hogan, R.P. and B.P. Dalton: Performance of the Research Animal Holding Facility (RAHF) and General Purpose Work Station (GPWS) and other Hardware in the Microgravity Environment. SAE Technical Paper Series 911567, July 1991.
•Ames Research Center, Life Sciences Payload, Spacelab-3, 60 Day Report. P.X. Callahan, ed., NASA Ames Research Center, Space Life Sciences Payload Office, April 1985.