Space qualified software

STIX Instrument On-board Software (PRODEX)

Mission Background

The Solar Orbiter is one of the Cosmic vision M-Class ESA missions. The mission goal is to understand (and even predict) how the Sun creates and controls the Heliosphere. STIX is one of the Solar Orbiter’s on-board remote sensing instruments. STIX provides imaging spectroscopy of solar thermal and non-thermal X-ray emissions from approx. 4 to 150 keV, with unprecedented sensitivity and spatial resolution (near perihelion), and good spectral resolution. Launch is scheduled to 2017.


• Engineering support during project phases A, B & C/D
• StartUp SW – Mission critical SW (stored in PROM)
• Application SW (stored in FLASH memory)

STIX On-board Software features:

• Control of the instrument and interface to the spacecraft
• SpaceWire link interface, using the ‘CCSDS packet transfer protocol’ and ESA Packet Utilization Standard (PUS) TC/TM interface
• Housekeeping data acquisition and reporting
• FDIR (Failure detection, isolation and recovery) with a high level of autonomy
• Science data acquisition and storage in the instrument internal mass memory
• On-board data processing: Autonomous based on user parametrisation and Selective based on user TC
• Requests – possible to select data from the instrument internal archive in the mass memory
• SW developed in C language
• HW target: Leon 3FT IP core in FPGA


SWARM Accelerometer Instrument On-board Software (EOEP)

Mission background

The SWARM mission objective is to provide the best survey ever of the geomagnetic field and the first global representation of its variations on time scales from an hour to several years. The challenging part is to separate the contributions from the various magnetic field sources. SWARM, a constellation mission (3 identical satellites), simultaneously obtains a space-time characterisation of both the internal field sources in the Earth and the ionospheric-magnetospheric current systems. Launched on November 22, 2013.

• StartUp SW – Mission critical SW (stored in PROM)
• Application SW (stored in EEPROM)
• Engineering support during project phases B, C/D, E

Accelerometer On-board Software features:

• Science and Housekeeping data acquisition using multiple AD converters, measurement time-stamped with accuracy better than 1 millisecond
• ESA Packet Utilization Standard (PUS) TC/TM interface
• SW developed in C language, time critical routines in Assembly
• HW target was a significant performance constraint for the SW – x51 family 8-bit microcontroller (Space qualified 80C32E at 12 MHz with only 268 Dhrystones / 0.153 VAX MIPS)
• Priority scheduler for optimal utilization of limited CPU performance

HXRS (Solar Hard X-Ray Spectrometer)

• Instrument On-board SW
• Technology: On-board SW: 80C166 CPU, Assembly;Ground support and test equipment SW: C++, Windows

Mission background

Czech Solar Hard X-Ray Spectrometer aboard the NASA & U.S. Department of Defense & U.S. Department of Energy – Multispectral Thermal Imager satellite (MTI). Launched on March 12th, 2000 on a Taurus vehicle from VAFB, CA, USA, successful 18 month mission.


MIMOSA (Czech Microsatellite)

Spacecraft OBC On-board SW
• Main instrument (Microaccelerometer MAC-03) On-board SW
• Technology: On-board SW: 80C166 CPU, Assembly;
Ground support and test equipment SW: Linux, RTLinux, C/C+Mission background

MIMOSA (Microaccelerometric Measurements of Satellite Accelerations) was a Czech microsatellite, principal investigator of the project was Astronomical Institute of Academy of Sciences (ASU CAS) Ondřejov, Czech Republic (Czech national funding). Launched on June 30th, 2003 on Rockot KS / Breeze (Eurockot) from Plesetsk in northern Russia.

Demise Observation Capsule (DOC)


The DOC shall be carried on-board the host vehicle (e.g. VEGA) by means of physical fixations, and shall be capable to autonomously perform its mission, including the safe separation from the host vehicle following the critical re-entry phase, and the transfer of the collected data to ground without the need to be recovered.

• SW Engineering
• Technology: C language

On-board SW

The on-board software is considered to be a fully automated system, which will carry out its mission with no intervention from ground

operators during any part of a mission.

The concept behind the FSW (Flight SW) is that of having a linear sequence of modes (from stand-by/launch mode to atmospheric free-fall mode), with predefined triggers controlling the transitions between modes. In-flight data transfer via a commercially-available global telecommunication system (Iridium).

Real-time operating system (FreeRTOS).



Download datasheet in PDF:

Space qualified software datasheet