Chapter 4 Photo Credits

• NASA Image Exchange

  hpoweredbus.jpg marsbase.jpg shuttlefuelcell.jpg

• Murdock Gas Plant, courtesy of http://www.umr.edu/~hatheway/GasPlantComponents.html
• The following images are believed to be in the public domain

  guldberg_waage.jpg

• All other photography and artwork is Copyright © 2000 Digipac Microcomputer Software Ltd.