NASA and Stanford University have developed and tested a new parrafin-based rocket fuel. The by-broducts of combustion are water and CO2.
News Release at http://amesnews.arc.nasa.gov/releases/2003/03_04AR.html
Photos at http://amesnews.arc.nasa.gov/releases/2003/03images/paraffin/paraffin.html
I like the ides that the Shuttles solid boosters can be throttled back or shut-down/restarted.
batty (Let's light those candles) den