HL-20 Spaceplane 3D model

cgtrader

The HL-20 Personnel Launch System (PLS) was a crewed spaceplane proposed by NASA in the early 1990s, intended to augment the Space Shuttle for routine space station crew and cargo missions as well as simple free-flying missions. It would have launched as a payload on top of an expendable or partially-expendable launch vehicle such as Titan III, the Advanced Launch System, or National Launch System. With its small size, HL-20 was expected to be cheaper and safer to operate than the Shuttle orbiter, and it was also to be capable of longer-duration stays at the space station.