The Gemini GT-3 spacecraft electrical system is a two-wire, grounded system using silver-zinc Eagle Picher batteries as sources of 25 VDC electrical power. There is no primary AC electrical power system on the spacecraft. Devices utilizing AC power obtain that power from self-contained inverters within the individual systems.
Prior to launch, external electrical power is provided to the spacecraft through the umbilical to prevent undue depletion of the spacecraft power supply. The battery subsystem is capable of supplying sufficient power to the electrically operated equipment for all phases of the planned GT-3 mission. In addition, sufficient power is available for a prelaunch period of two hours and a postlanding period of 36 hours for operation of necessary recovery equipment and for 12 hours of post landing suit compressor operation.
Ten silver-zinc batteries are provided, each activated and sealed at sea level pressure. The battery cases are vented to permit the escape of gases. Battery temperatures are controlled by mounting the battery cases in direct contact with spacecraft coldplates.
The reentry module main batteries supply a portion of the main bus electrical power during launch and all of the main bus electrical power during reentry,landing and postlanding. These four batteries are located in the right-hand equipment bay outside the pressurized area of the reentry module.
The squib batteries supply electrical power for squib-activated pyrotechnic devices throughout the entire mission. Squib batteries are isolated both electrically and mechanically from all other batteries. The three squib batteries are located ir the right-hand equipment bay outside the pressurized area of the reentry module.
It is possible to connect squid circuitry to the reentry main batteries in case of squib battery malfunction.
The three adapter batteries supply power to the main bus and are capable of supplying all of the electrical power necessary for spacecraft operation until separation of the adapter module.
To insure smooth system operation, complete electrical system management by the crew is provided. Extensive circuit protection is incorporated thoughout the system and indicators are mounted on the instrument panel for use by the astronauts in systems monitoring.
Copyright 1997, 1998, 1999 by John
Duncan |