New Techniques and Instrumentation – TEXUS Service Module (TSM)

Abstract

Until the TEXUS-42 (EML-1) project, successfully launched in Dec. 2005, the payload of the TEXUS and the MAXUS were equipped with the former Kayser-Threde 12 bit based PCM data acquisition system. To fulfill experimental requirements for higher data resolution and the intention to reduce weight and also to improve the performance of the service module, ESA has taken initiative to contract industry for the development and built up of a new data acquisition system and the new TEXUS Service Module (TSM) in 2004. For the design, manufacturing and qualification task sharing, a cooperation of DLR Moraba and the Kayser-Threde GmbH has been initialized. With respect to the compatibility of already existing experiment modules, Kayser-Threde has developed, manufactured and qualified the decentralized 16 bit CTS 3000 (Compact Telemetry System) data acquisition system and together with DLR Moraba the TSM. In order to improve existing systems and to comply with new requirements the DLR/Moraba has designed a new power distribution and a GPS system. The TSM is incorporating all known standard features, modern technologies and is capable of serving actual and future experiment requirements. The TSM provides flexibility for future implementation of up to two digital TV respectively TM down links besides the three standard analog TV down links. The design implies economic technical concepts consuming a minimum of service module mass and length. The service module acquires and transmits all experimental and service system housekeeping data via telemetry transmitter to ground. Commands to the service system and for experiment control are received with a dedicated diversity system from the ground station and distributed onboard. Furthermore three TV down links, 3-axis micro-g and acceleration measurement as well as a rate control (RCS) and a GPS system are incorporated. The TSM is integrated within a standard TEXUS cylindrical structure with Radax flanges on both ends. Most of the components are assembled on the instrumentation deck, which is fixated via shock mounts to the outer structure. All electronic boards for TM/TC, RCS, power switching, sequencing, μ-g measurement and housekeeping are integrated and wired within one.