| Structure | 77 pounds |
| Solar panels | 48 pounds |
| Electronics | 146 pounds |
| Propulsion | 32 pounds |
| Battery | 33 pounds |
| Scientific experiments | 41 pounds |
| Miscellaneous equipment | 70 pounds |
| Gross weight | 447 pounds |
THE POWER SYSTEM
Mariner II was self-sufficient in power. It converted energy from sunlight into electrical current through the use of solar panels composed of photoelectric cells which charged a battery installed in one of the six chassis on the hexagonal base. The control, switching, and regulating circuits were housed in another of the chassis cases.
This hexagonal frame, constructed of magnesium and aluminum, is the basic supporting structure around which the Mariner spacecraft is assembled.
Plan view from top showing six magnesium chassis hinged in open position.
VIEW LOOKING AFT ASSEMBLIES HINGED IN OPEN POSITION SCIENTIFIC EQUIPMENT ASSEMBLY I COMMUNICATIONS ASSEMBLY II DATA ENCODER AND COMMAND ASSEMBLY III ATTITUDE CONTROL AND CC AND S ASSEMBLY IV POWER ASSEMBLY V BATTERY ASSEMBLY VI
The battery operated the spacecraft systems during the period from launch until the solar panels were faced onto the Sun. In addition, the battery supplied power during trajectory maneuvers when the panels were temporarily out of sight of the Sun. It shared the demand for power when the panels were overloaded. The battery furnished power directly for switching various equipment in flight and for certain other heavy loads of brief duration, such as the detonation of explosive devices for releasing the solar panels.
