1. Fuel: Hydrogen is a clean-burning fuel that produces only water as a byproduct. It is being explored as an alternative to fossil fuels for transportation, electricity generation, and other applications.

2. Industrial feedstock: Hydrogen is used extensively in the production of ammonia, methanol, and other chemicals. It is also used in the refining of petroleum and the production of steel.

3. Rocket fuel: Hydrogen is a highly efficient and powerful rocket fuel, used by NASA and other space agencies. Its high energy density and low molecular weight make it ideal for propelling rockets and spacecraft.