Sorry, no definitions found.
Sorry, no etymologies found.
For surface-to-orbit vehicles, I employed methane/oxygen SSTO rockets, and assumed that the vehicles need to have a dry mass for thermal protection, engines, landing gear, etc. excluding tankage that is equal to their payload, or 50 tonnes.
Moreover, it is an unsuitable propellant for a cheap reusable space transportation system, since its costs exceed methane/oxygen propellant by more than an order of magnitude and its bulk makes it very difficult to transport to orbit in any quantity using reusable single-stage-to-orbit (SSTO) vehicles (thus ruling it out for true cheap surface-to-orbit systems).
Though tolerable, the shuttle journey was rougher than his single previous experience with the little surface-to-orbit vessels.
No co-pilot's necessary on a surface-to-orbit hop, and you'll get a good view from there. "