to initiate your request. See also AIAA Rights and Permissions www.aiaa.org/randp.

In the RETALT (RETro propulsion Assisted Landing Technologies) project vertical landing launcher configurations are investigated. In the aerodynamic phase of retro propulsion assisted descent and landing, the main devices for control and trim of the vehicle are the aerodynamic control surfaces. In this paper, experimental data of a novel concept where the interstage is divided in four segments which are used as aerodynamic control surface during the aerodynamic descent of the first stage is presented. The results are compared to theoretical results obtained using a simplified modelling of supersonic and hypersonic flow fields. The interstage segments show to be very effective in creating drag for aerodynamic deceleration in the atmosphere. A large deflection of the interstage segments can lead to largely unsteady flows. The deflection of only one interstage segment does not yield statically stable configurations.

No abstract

No abstract

Aerodynamic interactions of fragments of meteoroids and space debris during atmospheric entry influence the flight trajectories of the fragments and their strewn field on the Earth's surface as well as the meteoroids' airburst altitude and energy deposition rate in the atmosphere and thus the resulting ground damage. For the design of experiments in the Hypersonic Wind Tunnel H2K of DLR, German Aerospace Center in Cologne to investigate the interaction phenomena, a method is developed to estimate the forces on two interacting bodies in supersonic and hypersonic flows, which is more accurate than existing analytical and semi-analytical methods and more efficient than numerical simulations regarding the computational effort. It is based on the superposition of flowfields taken from a database of numerical simulations of a single body for a range of Mach numbers. Furthermore, three-dimensional computations of configurations of interacting bodies are carried out by NASA Ames Research Center. Results obtained with the superposition method are compared to the simulations by NASA and to results of computations that can be found in the literature. The results from the method show good agreement with the computations.Nomenclature a x 1 = streamwise acceleration of first sphere, m∕s 2