Josef Ettl

Instrumentation of the SHEFEX-II Flight Experiment and Selected Flight Data

The SHEFEX-II hypersonic flight experiment was launched from Andoya rocket range in Norway on 22.06.2012 consisting of an extensively instrumented scientific payload on top of a two-stage rocket configuration. With an apogee of about 177 km, the vehicle achieved flight velocities up to 2790 m/s corresponding to Mach numbers up to 9.3. Almost all heat flux, temperature and pressure sensors provided very clear data during ascent and descent phases. Measured pressure data from sensors at different locations of the scientific payload show consistent results concerning the aerodynamic behavior on the vehicle along the complete trajectory. Pressure fluctuations measured during ascent, show a good correlation to angle of attack variations. Calculated pressure coefficients from a CFD analysis at selected trajectory points are in good agreement with the measured pressure data.

MORABA - Overview on DLR's Mobile Rocket Base and Projects

Mobile Rocket Base (MORABA), a division of the Space Operations and Astronaut Training Department of DLR (Deutsches Zentrum fur Luft- und Raumfahrt) provides the national and international scientific community with the opportunity to prepare and implement rocket and balloon born experiments. The fields of research includes aeronomy, astronomy, geophysics, material science and hypersonic research and are conducted in cooperation with a variety of international patners. In addition satellite missions can be supported by mobile tracking radars for trajectory determination and TT&C mobile ground stations. MORABA also offers a number of mechanical and electrical systems for use on rocket, balloon and short term satellite missions. During the last four decades more than 250 campaigns have been performed in Antarctica, Australia, Brazil, France, Greenland, India, Italy, Japan, Norway, Spain, Sweden and USA. Depending on the scientific objective, an appropriate launch range is selected and complemented or fully equipped with MORABA’s mobile infrastructure, such as launcher, telemetry and tracking stations. MORABA supplies the suitable converted military surplus or commercial launch vehicles, as well as all necessary mechanical and electrical subsystems to the customers. This paper gives an overview of the MORABA infrastructure for sounding rocket launching and satellite TT&C. A short survey of MORABA projects of the last two years and the next two years is also provided.

Using data fusion of DMARS-R-IMU and GPS data for improving attitude determination accuracy

The Mobile Rocket Base (MORABA), a division of the Space Operations and Astronaut Training Department of the German Aerospace Center, has developed and flown sounding rocket rate and attitude control systems since 1972. For determining position and attitude, some of the past missions have used a DMARS-R (Digital Miniature Attitude Reference System) roll stabilized platform produced by the Inertial Science Company. The DMARS-R is a high-precision, roll-stabilized IMU (Inertial Measurement Unit) comprising accurate angular rate and acceleration sensors and mounted on a roll-stabilized platform. Standard IMUs are inherently subject to drift in inertial position, velocity and attitude. By the fusion of GPS and with DMARS-R data, one can achieve a long-term drift-corrected IMU enabling for longer duration flight applications, such as satellite launchers, spin stabilized rockets and balloons. The main experiment of the MAIUS mission, initially planned for autumn 2015, requires accurate pointing to the Earth’s gravitational center. The required accuracy will be obtained by the fusion of DMARS-R and GNS data to produce “drift free” attitude data for the cold gas attitude control system of the payload. The attitude correction and control algorithm will be implemented in the DMARS-R processor.