Originally Posted by blackshire

"freezing out" contractors outside of their "inner circle" of legacy suppliers. If they don't want to use a company's hardware--for whatever reason--and a university experimenter wants to fly a payload at Wallops, White Sands, Poker Flat, or another fixed or mobile range that NASA uses, the experimenter has to settle for whatever NASA-used rocket(s) best fit his or her requirements.

Throttlable, reloadable hybrids would be even safer than liquids for suborbital VTOVL spacecraft, having TNT equivalences of zero. (For suborbital vehicles, where the mass ratio isn't so critical, the hybrid motors could have tough, thick-walled maraging steel motor cases that could be reloaded many times. The aft closure could be bolted on for ease of fuel grain casting, or a gel-type uncured fuel [which would cure into a hard rubber fuel grain] could be pumped into a "unitary" hybrid motor case, using an inflatable or dissolveable mandrel to create the center void in the fuel grain.)