The following links to sites are not part of the "Mission to Mars" material, but provide information that may be of interest.

Emile Clapeyron (1799-1864): biography

Rudolf Clausius (1822-1888): biography

Coal Gas: More information about coal gas, and its environmental problems is available at:

• Environmental Remediation
• History and Contaminants at Marshalltown
• Coal Virtual Library

Fuel Cells: Some interesting links to information about fuel cells are:

• What are fuel cells? (from NASA)
• Anuvu Inc: PEM Fuel Cells for Transportation, Stationary Power Generation, and Portable Power
• Fuel Cell Vehicles

PET plastics: more information about the properties of PET plastics.

World Energy Reserves: Statistics and considerable other information about energy is available at: http://www.eia.doe.gov/