I'll post here to say that if you can use a spreadsheet I can help you get to very close approximations of fuel burn etc. No secrets. No midnight knocks on the door. But really the information is out there in text books and so much fun to apply to simming that I wonder "Why seek on the net when you can do it yourself?" What did the Jockanese engineer say in "Space Trek"? Was it "Ye canna change the laws of physics!"? I think so. Searching for answers is one thing. Searching how to come up with answers is a better thing. If you and your moderators want a little gentle input, I can try to put a little back into what has given me a very happy life.