BTW, I had an idea for cheap access to orbit using a helium balloon, solar panels, and electrodynamic tether propulsion (http://en.wikipedia.org/wiki/Tether_pro

BTW, I had an idea for cheap access to orbit using a helium balloon, solar panels, and electrodynamic tether propulsion (http://en.wikipedia.org/wiki/Tether_propulsion http://en.wikipedia.org/wiki/Tether_propulsion) But alas my math skills aren't up to the task of figuring out if it's viable. Someday I'll figure it out and you guys will see a blog post on it.