In general, Murphy's Do The Math crowd don't do math . Rather they appeal to Murphy's authority and hurl insults. Mike Stasse...

Patching Conics Time and time again I've watched people patch conics by using straight addition and ignoring the Oberth benefit. It is...

My Conic Sections & Celestial Mechanics Coloring Book __________________________ Those who advocate Mars settlement like to say...

Most of my models use circular coplanar orbits. But Jon Goff points out many asteroids have a healthy inclination. Departing for an asteroi...

This is in response to Quantum G's  question " Why do humans need to return to the Moon to get resources to make "consumables...

This post was prompted by Robert Walker 's comment: " I wonder what anyone here thinks about my idea for rotating carousels to pr...

"What's the cost of propellant from earth vs getting it from the moon?" always comes up in discussions of lunar water. Or the ...