Design and Research of Multiple Data Channels in Solid State Recorder of the Satellite SJ-10

Space borne high-capacity solid state recorder (SSR) is an inevitable chain of the space scientific data acquirement system. It has become a common device in spacecraft gradually. This paper presents the design and accomplishment of the large capacity SSR design based on NAND flash of the satellite SJ-10. The SSR improves its writing speed significantly by applying multi-pipeline writing technique. External SDRAM is used as the channel cache of the multi-channel data flows to increase the cache capacity and system throughput speed. In addition, the EDAC processing, data flow combining and separating can enhance the stability of the storage system as well as the data efficiently. The implementing of multi-channel has also laid the foundation for file system management of the space borne storage data. The simulation of multi-channel data flow is given in this paper.

Design and Structural Analysis of the Solid-State Recorder for Missile Flying Parameters Recording

While the flying test of the missile, many kinds of parameters need to be recorded and the recording instruments are working in harsh environment. For this particular application a Solid-state recorder had been designed for obtaining and recording flying parameters of the missile, including data acquisition module, power management module, the central control module, a data storage module, the reading interface module, etc. Meanwhile, analyzed structures of the Solid-state recorder and completed thermal analysis and impact stress analysis of the structure using finite element analysis software ANSYS. The results had shown that the recorder can survive well in the flying test of the missile and the recorder had been applied to the actual trial and got accurate and reliable data.

Enhanced timing accuracy for Cluster data

The standard timing accuracy for the Cluster mission is ±2 ms. However for inter-spacecraft comparisons of waveform data a much higher accuracy is needed – for example a timing error of 1 ms results in a phase error of 65° for a signal at 180 Hz. Most Cluster data are recorded on an onboard solid state recorder and time stamped using an onboard clock which is calibrated to UTC. Until recently, the error of this onboard clock was allowed to increase to the ±2 ms limit before a new calibration was applied. However, the timing error for real time data is estimated to be only ~11 μs, so these data may be used to prepare a time correction dataset which allows the standard timing accuracy to be improved considerably. This paper describes the details of the preparation and validation of this dataset. Two independent source datasets are used: telemetry to ESTRACK ground stations supporting the main operations of the Cluster spacecraft, and the real time telemetry to the NASA DSN stations supporting the Wide-Band Plasma Wave Investigation.