The European Student Earth Orbiter (ESEO) is a micro-satellite mission to Low Earth Orbit and is being developed, integrated, and tested by European university students as an ESA Education Office project. AMSAT-UK and Surrey Space Centre are contributing to the mission with a transceiver and transponder similar to that of FUNcube-1 with the addition of utilising a Atmel AT32 processor for packet software-redundancy, baseband processing, forward error correction, and packet forming; acting as a step towards software defined radio using low MIPS automotive microprocessors. As on the FUNcube-1 satellite, the telemetry formats and encoding schemes presented utilize a large ground network of receivers on the VHF downlink and conforms to 1200 bps and a new 4800 bps redundant downlink for the rest of the spacecraft. The uplink is on L-band using bespoke partial-CCSDS frames. This paper details the flight software on the engineering and flight models to ESA, and the technical configuration and associated tests of demonstrating the processor load is under for varying operating and sampling modes. In particular, a key contribution will be the details of utilising the Google Test Suite for verification of the SDR functions and FreeRTOS tools to optimize processor load margins to 30% when operating parallelized ADC and DAC, and CAN-open telemetry chains and what memory considerations are needed to ensure stable long-term operations.
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机译：欧洲学生地球轨道器（ESEO）是对低地球轨道的微型卫星飞行任务，作为ESA教育办公室项目，欧洲大学生正在对其进行开发，集成和测试。 AMSAT-UK和萨里航天中心通过类似于FUNcube-1的收发器和转发器为任务做出了贡献，此外还利用Atmel AT32处理器进行数据包软件冗余，基带处理，前向纠错和数据包形成；使用低MIPS汽车微处理器向软件定义无线电迈进了一步。就像在FUNcube-1卫星上一样，提出的遥测格式和编码方案在VHF下行链路上利用了大型的接收器地面网络，并符合航天器其余部分的1200 bps和新的4800 bps冗余下行链路。上行链路使用定制的部分CCSDS帧在L波段上。本文详细介绍了用于ESA的工程软件和飞行模型的飞行软件，以及用于证明处理器负载在各种操作和采样模式下的技术配置和相关测试。特别是，关键的贡献将是利用Google Test Suite验证SDR功能和FreeRTOS工具的细节，以在并行ADC和DAC以及CAN开放式遥测链上运行时将处理器负载裕量优化到30％，以及注意哪些内存需要确保稳定的长期运行。
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