There have been tons and tons of articles written about "Why can't we rebuild the Saturn V" and so forth. I eventually decided to set up a spreadsheet that allows people to play rocket lego with modern engines, etc., to see what it takes to duplicate the Saturn V's performance.I went through a few iterations and worked out a lot of the kinks. It seems to work quite well, giving accurate payload figures for the Saturn V as well as the Atlas V. I haven't yet added on the capability to give first-stage SRBs but that is coming next.If anyone would like to play around with it and see if there are any obvious problems, let me know! Also, if anyone would be able to turn this into a web app, that could be really useful.Here's the Google spreadsheet. You can either play around with it as-is (anon users can only edit the independent variables) or download/copy and go from there.https://docs.google.com/spreadsheets/d/1UNuPfjZE-YVIrmLINiUMcOzJk-voZ2TqM6R7MgyaM-I/edit?usp=sharingThe first three tabs are all separate "sandbox" sheets so you can feel free to play around with them, even if there are multiple people in the spreadsheet. You can start by putting the Saturn V engines onto stages that use modern construction, or putting modern engines on the original Saturn V stages, etc.