The hypersonic aeroelastic and aerothermoelastic problem of a double-wedge airfoil typical cross-section is studied using three different unsteady aerodynamic loads: (1) third-order piston theory, (2) Euler aerodynamics, and (3) Navier-Stokes aerodynamics. Computational aeroelastic response results are used to obtain frequency and damping characteristics, and compared with those from piston the...

Atmospheric flight phase of a launch vehicle is utilized to evaluate the performance of an H∞ controller in the presence of disturbances. Dynamics of the vehicle is linearly modeled using time-varying parameters. An operating point was found to design a robust command tracker using H∞ control theory that guarantees a stable maneuver. At the end, the controller was employed on the launch vehicle...

The Air Launch System Enabling Technology (ALSET) project is a Japanese Ministry of Economy, Trade and Industry (METI) funded project whose purpose is to study air launch orbital payload delivery systems and related technologies. The project is a first step toward an operational commercial air launch system that will use a multistage solid rocket to deliver small payloads on the order of 100 to...

This paper addresses different methods for determining the amount of extra propellant (flight performance reserve or FPR) that is necessary to reach orbit with a high probability of success. One approach involves assuming that the various influential parameters are independent and that the result behaves as a Gaussian. Alternatively, probabilistic models may be used to determine the vehicle and...

CS7BL/6 mice were infected as neonates or as adults with Rauscher leukemia virus (RLV) and were challenged at various times thereafter with syngeneic Rauscher lymphoma cells. In addition, sera obtained prior to challenge were tested by immunofluorescence against Rauscher lymphoma cells. Mice infected as adults with a 10' dilution of RLV exhibited strong transplantation resistance within 1 week ...