Design
| Enviro |
Astro | Propulsion
| Power | Thermal
| Structures | AD&C
| CDHS |
Test
Chemical
energy is stored in batteries
and used to supply spacecraft
power requirements during eclipse times when solar
arrays are shadowed by Earth.
Batteries
Electrolyte
material in batteries has
a chemical reaction during charging that stores
electrical energy as chemical energy. When a battery
is used as an electrical source or discharged, this
chemical reaction reverses and chemical energy is
converted back into electrical energy.
Electrodes
work within an electrolyte to collect or emit electrons.
The anode, positive pole, collects positive ions;
the cathode, negative pole, collects negative ions.
Primary
batteries are designed for
a one-time use and are not rechargeable. They are
typically the sole electrical source for missions
lasting less than one month.
Secondary
batteries are designed for multiple uses and are
rechargeable. Nickel-cadmium and Nickel-hydrogen
are two of the most popular types.
Fuel
cells are
not batteries, but they are used in similar ways.
They provide lots of power for short periods and
are ideal for human missions under two weeks duration.
Two reactive compounds mix producing current from
their chemical reaction. Hydrogen and oxygen are
the most common reactants, since one of their byproducts
is water.
