Eight fixed-wing reusable horizontal landing booster point design concepts are presented and compared on the basis of weight, cost, technical difficulty, and availability date. The eight vehicle types considered are all basically two-stage systems with a lifting body reusable second stage, with all vehicles normalized to place 40,000 lbs. payload in orbit. All flight vehicles are fully recoverable and capable of flying back and landing at the launch site. Vehicle types discussed are vertical take-off horizontal landing rockets, sled launched horizontal take-off rockets, runway launched horizontal take-off rockets, air breathing first stages, combined air breathing and rocket first stages, oxidizer collection concepts, supersonic combustion ramjets, and in-flight refueling vehicles. Each of these vehicle types is depicted in the paper and its design and performance characteristics are discussed.
System non-recurring costs tend to be proportional to the inert weight of the vehicle, and therefore the rocket propelled vehicles have lower investment costs than the airbreathing types. The turnaround or recurring costs are relatively independent of the launch vehicle types with the exception of the in-flight refueling system, which is about double those of the other systems because of the large weight of flight hardware to be maintained. The airbreathing first stage boosters, however, may offer more mission flexibility than the rocket first stages because of their capability to fly for longer periods within the earth's atmosphere.