The Asolant/Rubin-5 Technology Demonstration Mission - System Description and First Flight Results

This paper addresses the Asolant/Rubin-5 flight experiment conducted onboard the upper stage of a Cosmos rocket in late 2005. The main objective of the project was to flight-qualify a newly developed combined solar cell/antenna device, the so-called Advanced SOLar ANTenna (ASOLANT) technology. In order to assess both, the reception as well as emission of R/F signals, two different devices were involved in the mission. One was linked to a space-borne Phoenix-S GPS receiver to examine the receiving performance. A second device was designed to send out S-Band beacon signals generated by the SAFIR-S amateur radio transmitter to evaluate the radiation characteristics. Moreover, both ASOLANT devices supplied the electrical power for the onboard systems. Telecommand and telemetry functionalities were provided by an ORBCOMM communicator making use of the ORBCOMM satellite network to relay data between space and ground. This unit, furthermore, served as onboard computer. The experiment was launched along with eight multinational payload satellites. It was designed to remain attached to the rockets upper stage after burnout. Due to a separation failure of one of the copassengers, the primary mission objectives could not be fully met. Nevertheless, a sufficient number of data was retrieved to confirm the good overall performance of the ASOLANT devices. Roughly ten month after the launch, still most system components are operational and experiment data are transmitted to ground. Following a description of the main flight system components and the overall ystem architecture, the paper summarizes the hitherto obtained experiment results

Risk perception or self perception

In cognitive entrepreneurship research one main question is: Do entrepreneurs think differently than others in various ways? Especially in the area of risk perception cognition is thought of as information processing. In later streams of cognitive science it has developed from a state where cognition is seen as information processing to a state where cognition is mainly seen as an effective act, where experiences play an important role. We use risk perception as an indicator for information processing and self perception as an indicator for past experience. We found that past experience explains starting a real venture whereas risk information processing explains starting a case study venture

Analysing commercials' success from a social constructivist perspective

From a social constructivist perspective (SCP) we analyse TV-commercials’ success. We address the following questions: Does the customer co-create meaning, and, more specific, is a commercial more successful if a customer plays a co-creating role? If so, both the customer and her experience, as well as the commercial, play a significant part in explaining the commercial’s success. As independent constructs to explain commercials’ success we used storytelling, indicating the commercial’s part, and experiential conclusiveness, indicating the customer’s part. We found support that the customer and seller via the commercial co-create meaning and coordinate their activities

Evaluating differential GNSS techniques for landing the 1st stage of an RLV – with a skydiver experiment

Reusable launch vehicles (RLV) in a vertical take-off vertical landing configuration require accurate measurements of the height above the ground during the final descent just before landing. It is proposed to use real-time kinematic positioning (RTK), which is a differential GNSS navigation method requiring a nearby reference GNSS antenna and receiver, to measure the rover’s position with centimetre accuracy. The effects of the engine plume, vibration and multipath are challenging when using this carrier-phase based positioning method on an RLV. Especially the residual differential tropospheric error due to the rover and reference GNSS antennas being at different heights, primarily caused by humidity in the air, may hinder the successful fixing of the carrier phase ambiguities. To gain a better understanding of the RTK performance to be expected on a landing RLV, a skydiver experiment was conducted in April 2022. The skydiver was equipped with a rover GNSS receiver and a helmet with a GNSS antenna on top and an independent integrated navigation system serving as reference. The skydiver reached free fall velocities of up to 385 km/h, which is seen representative of the vertical velocity of an RLV. The paper describes the experiment procedure and the results of the experiment

Kodiak: A versatile special purpose multi-GNSS receiver for highly dynamic sounding rocket applications

The Kodiak GNSS receiver is a modular and versatile GNSS receiver platform that has been developed by DLR specifically for high dynamic space applications such as sounding rockets, launch vehicles or re-entry vehicles. It is a successor to the widely used Phoenix GPS receiver. Its flexible design allows various use cases like rocket- or other high dynamic applications. Features are: estiamation of the 6DoF state of vehicles by fusing the receivers position and velocity with the inertial navigation solution, orientation estimation from relative carrier phase measurements of signals of two or more antennas, adaption of tracking depending on the flight phase forecasting of Doppler frequencies based on current velocity estimations of the IMU solution. This paper presents first flight results of the Kodiak receiver

Reale Erfahrungen in einer virtuellen Welt: Erfahrungen beim universitären Einsatz eines Unternehmensplanspieles

Die veränderten Bedingungen der heutigen Wirtschaftswelt erfordern nicht mehr nur grundlegendes Faktenwissen . Da Faktenwissen im Internetzeitalter kein knappes Gut mehr ist, zählen in der Praxis immer mehr die einzelnen Fähigkeiten des Menschen, also mit Wissen umzugehen und es zur Gestaltung zu nutzen. So stehen bei den Arbeitgebern heutzutage weniger die Abschlussnoten als die praktischen Fähigkeiten im Vordergrund. Wie ist es nun möglich, diese Fähigkeiten bereits während des Studiums zu erlernen bzw. diese zu trainieren? Dazu soll als erstes einmal auf die einzelnen Komponenten eingegangen werden, die zur Entstehung von praktischen Fähigkeiten bzw. Können erforderlich sind. Fähigkeiten bestehen aus einer Lern- und einer praktischen Komponente. Sie können somit als Stimme von Wissen und Erfahrungen interpretiert werden. Erfahrungen erlangt man durch die Anwendung und Reflexion von Wissen, also von erlernten Methoden und relevanten Informationen

CALLISTO: towards reusability of a rocket stage: current status

JAXA, CNES and DLR have decided to cooperate to develop and fly a scaled reusable VTVL rocket stage called CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss - back Operations). This vehicle is paving the way for future reusable launch vehicles in Europe and in Japan. During phase B important progress in term of methods and operation philosophy specific to RLV have been made. Amongst other progresses, that will ease the development of future operational VTVL, in the domain of aerodynamic modelling, GNC landing leg deployment but also flight domain definitions are presented. These are concrete results which can at least partly be useful for other RLV projects

GPS for Microsatellites - Status and Perspectives

GPS receivers nowadays provide a well established system for tracking of spacecraft in low-Earth orbit (LEO). In addition, GPS receivers serve as instruments for geodetic and atmospheric research on an ever growing number of science missions. The paper provides an overview of existing GPS receivers for LEO satellites, covering both fully space qualified as well as commercial-off-the-shelf (COTS) systems. The needs of pure navigation receivers and advanced science instruments are independently discussed and directions for future systems are identified. Potential benefits of the new Galileo constellation are addressed and recommendations for future receiver developments are given

GPS Based Attitude Determination for the Flying Laptop Satellite

This paper introduces the GPS based attitude determination system (GENIUS) onboard the university small satellite Flying Laptop. The attitude determination algorithm which is based on a Kalman Filter and processes single differences of the C/A-code and carrier phase measurements is shortly described. The algorithm uses the LAMBDA-method to resolve the integer ambiguities of the double differences of the carrier phase measurements. These resolved ambiguities are then used to fix the single difference ambiguities in the filter. The results of ground based tests and numerical simulations are introduced and the accuracy of the attitude determination algorithm is assessed