Lost everything in the forum crash. But I'm back. I posted to the main page but should have done so here but missed the hello again thread at first. No way to move it yet. I'm thinking I want to do a mod of an actual solar-thermal engine. It has an ISP around 1200 sec in its most efficient form, and an ISP of 800 sec in an easier to build form. Either would get us to Mars without all the NERVA anti-nuke politiks. However, I'm not sure where to start as I don't own any 3d tools and most free ones are crap. Given the ISP of such an engine it beats nuclear I'd like to popularize the idea. I'm not exactly someone who can call up Elon Musk and say "Try THIS to get to Mars...." I need something I can model mirrors on and make them extensensible or something. I've got extensive Visual Studio/C++ experience but haven't done 3d modelling before. Anyway, I'm still working on rovers and landing them. Here's my latest accident and rescue....