Question

Name the cell which was used in the Apollo space programme for providing electrical power.

Hint:

Fuel cells convert chemical energy directly into electrical energy. Apollo missions used H\(_2\)–O\(_2\) fuel cells.

Answer 1

Concept:
Space missions require a dependable and ongoing power source. For the Apollo space program, electrochemical cells were employed to directly convert chemical energy into electrical energy, providing the necessary power for the spacecraft.

Step 1: Type of fuel cell used.
The power source used in the Apollo spacecraft was the Hydrogen–Oxygen fuel cell.

Step 2: Working mechanism of the fuel cell.
In the Hydrogen–Oxygen fuel cell:

• Hydrogen gas is oxidized at the anode, releasing electrons.
• Oxygen gas is reduced at the cathode, accepting the electrons from the anode.
• The combination of hydrogen and oxygen produces water as a byproduct and generates electrical energy.

The overall chemical reaction in the fuel cell is: \[ 2H_2 + O_2 \rightarrow 2H_2O \]
Step 3: Benefits of the fuel cell in space missions.
The Hydrogen–Oxygen fuel cell offered several advantages during space missions:

• It operates with high efficiency, making the best use of fuel.
• It provides a continuous and stable power supply throughout the mission.
• Water produced during the reaction could be used by astronauts for drinking and other needs.

Therefore, the fuel cell used in the Apollo space program was the Hydrogen–Oxygen fuel cell.