Scenario: Apparent rocket based drive equipped vessels regularly SSTO to and fro from planets. Two stage to orbit no longer is used at at all... since even heavy vessels can SSTO. Radiation pollution from exhaust is not even an issue since exhaust is NOT radioactive.   How is this even possible?   Indulge me a bit in my imagination if you will. I do like this idea and think it is one of my better ones... since you can literally take ANY chemical rocket today and pai