The NASA Langley Research Center has been performing studies to address the feasibility of various single-stage to orbit concepts for use by NASA and the commercial launch industry to provide a lower cost access to space. Some work on the conceptual design of a typical lifting body concept vehicle, designated VentureStarTM has been conducted in cooperation with the Lockheed Martin Skunk Works. ...

In the application of adaptive flight control, significant issues arise due to vehicle input characteristics such as actuator position limits, actuator position rate limits, and linear input dynamics. The concept of modifying a reference model to prevent an adaptation law from “seeing” and adapting-to these system characteristics is introduced. A specific adaptive control method based on this c...

This paper presents an application of the nonlinear optimal control techniques to the design of launch vehicle autopilots. The optimal control is given by the solution to the Hamilton-Jacobi-Bellman (HJB) equation, which in this case cannot be solved explicity. A method based upon Successive Galerkin Approximation (SGA), is used to obtain an approximate optimal solution. Simulation results invo...

Improvement of the launch phase of a jet powered Unmanned Aerial Vehicle (UAV) with Jet Assisted Take Off (JATO), has been the subject of attention in the UAV industry. Use of flight simulation tools reduces the risk and required some amount of flight testing for complex aerospace systems. Full nonlinear equations of motion are used to study and simulate this maneuver and three case studies of ...

With a mission to Mars no longer merely an idea of science fiction, it is not too early to determine the technology requirements that will ultimately make it possible for humans to establish a long term outpost on Mars. One key aspect is the development of a reliable, reusable launch vehicle to shuttle astronauts between the Mars surface and low Martian orbit. This preliminary design study serv...

A review of the experimental and computational studies performed at NASA Langley Research Center (LaRC) to support the optimization and benchmarking of the hypersonic aerodynamic and aerothermodynamic databases for the X-33 vehicle is presented. A synoptic of the testing, computational, and analysis capabilities at LaRC applied to these studies is given. Analyses of the hypersonic aerodynamic c...

Over the last century chemical propellants have been the dominant fuel source for the aviation and aerospace industry, primarily because they are able to provide ample power for a limited cost. However, over the last decade as the price of chemical propellant continues to soar and their detrimental effect on our environment comes to light, there has been a surge to develop an alternative propul...