Space Travel 101: Fundamentals of Space Travel

Analysis Fuel cells are electrochemical conversion devices that produce energy by converting hydrogen and oxygen into water. It is possible to produce electricity through this chemical reaction because hydrogen and oxygen release an electron when they are combined to form water. Electrons that are produced from the chemical reactions are collected to provide to provide electricity for anything connected to the fuel cell. Refueling a fuel cell is easy, since it basically needs a supply of hydrogen and oxygen. On a spacecraft, an external power source, such as a solar panel, can be used to easily split the water that was produced from the chemical reaction back into hydrogen and oxygen. Fuel cells are useful because they generally last longer than batteries do and do not require any expensive radioactive parts. However, they are extremely heavy and therefore use up a lot of valuable propulsion fuel. The price of carrying the fuel to support the weight of fuel cells is often not cost efficient, so it is sometimes better to use an alternate power source.