Payload Capability of Kerosene-Fueled Mini Shuttle

Introduction T HE Space Shuttle or Space Transportation System (STS) is a beautifully designed reusable launch vehicle (RLV). With the exception of the external tank (ET), all of its components are recovered, refurbished, and used again. Despite its many critics and high operating costs, it has been a workhorse in space for nearly 15 years of service with an unparalleled record of safety and reliability. The one  ight in more than 75 that ended tragically was found to have resulted from an O-ring failure in one solid rocket booster (SRB), which could have been avoided with proper launch precautions. Now, however, NASA is intent on developing a replacement spacecraft for the Shuttle thatwill be available in about 10–15 years and will provide considerably cheaper access to space. In spite of the demise of the National Aerospace Plane (NASP) program, the concept of a reusable single-stage-to-orbit (SSTO) vehicle is still considered viable.2;3 As a result, in 1996 a three-year contract was awarded to Lockheed Martin for development of the X-33 technology demonstrator.4 This is a subscaleprototypeof the Lockheed Martin VentureStar,which is envisionedas an SSTO RLV to replace the Shuttle.4 In its comprehensive access-to-space study, NASA considered three alternative courses of action to meet anticipated needs of the United States in launch capability through the year 2030. 1) Make necessary upgrades and continue primary reliance on the Space Shuttle and today’s  eet of expendable launch vehicles (ELVs) through 2030. 2) Develop a new expendable launch system that utilizes today’s state-of-the-art technology and begin the transition from the Shuttle and current ELVs in 2005. 3) Develop a new reusable advanced-technology,next-generation launch system and make the transition from today’s Shuttle and ELVs from 2006 to 2010. In the  nal analysis, option 3 was deemed the most desirable and was recommended for consideration by the President’s Of ce of Science and Technology Policy. There are three alternative architectures in option 3 consisting of two reusable SSTO vehicles and one reusable two-stage vehicle. Two of the vehiclesuse air-breathing/rocket propulsionand one uses only rocket propulsion. Since publication of the NASA study in 1994, several option-3-type design concepts using only rocket propulsion have been reported. First, there is the NASA reference winged-body, vertical takeoff/horizontal landing (VTHL) design, which is a combination of a long cylindrical fuselage and a delta wing. Second, there is a cone-shaped,vertical takeoff/vertical landing vehicle without wings.6 Third, there is the delta-wing-shaped, lifting-body VTHL design, which has evolved into the Lockheed Martin X-33/VentureStar vehicle.4 A fourth reusable SSTO design is the wingless bent-biconic vehicle, which relies on a drag chute for stabilizationduring transonic  ight and a para-wing for landing. The authors of the paper on this last design point out some stability and control problems with the  rst two designs and a structural weight problemwith the lifting-bodydesign of the LockheedMartin VentureStar.8 Perhaps it might be well for NASA to reconsider the viability of the SSTO RLV concept. The NASP experience was a costly and wasteful one, of both time and money, and should not be repeated. Moreover, there is a new entry into the RLV sweepstakes that just might, when combined with the Shuttle-II concept, be the answer