The Netherlands provides standard components, without which spaceflight would not be possible. Solar panels for power and attitude and orbit control systems to determine a satellite’s position are consistently provided by Dutch companies.
Rosetta\'s solar panels being tested in Noordwijk - image: ESAThe Netherlands houses essential developments in solar power, the prime energy source for satellites in space. Dutch Space, ESA’s preferred supplier, has researched and developed advanced solar array technology since 1973. Advanced Rigid Arrays combine a low mass solar array with high stowed stiffness in order to avoid interference with the most important spacecraft natural frequencies for a large variety of different configurations. Stork Fokker produced the solar array back panels for the METOP, PPF, Artemis, Envisat, SOHO, XMM and MSG missions. The honey-comb sandwich structures provide strength and are lightweight. Dutch Space’s ARA MkIII solar array has been developed and qualified to accommodate different add-on masses on the panel substrates and state of the art Silicon (Si) and Gallium Arsenide (GaAs) solar cells can be applied. Si and GaAs solar cells enable solar arrays to achieve a much more efficient power output and therefore use fewer cells. Newly developed thin film solar arrays will provide future missions with double the power-to-mass ratio of current arrays at half the weight and half the price. In cooperation with the Technical University of Delft the nano-satellite Delfi-C3 was launched in April 2009 with an onboard flight demonstration of this new technology.
Attitude & Orbit Control Systems (AOCS) are used to achieve and hold the geometrical objectives of satellites. The attitude of a satellite is important for pointing of payloads on-board and ensuring safety of the system. A stable orbit is key to fullfilling any satellite mission. Systems that are used for attitude and orbit control are e.g. Star Trackers, Sun Sensors and Gyroscopes for sensing the attitude, and thrusters, and reaction wheels as actuators. The control of these hardware components and the mission objectives is essential and typically consists of delicate and complex algorithms on robust computer systems. Dutch Space designed, produced and tested the Attitude & Orbit Control Systems for the scientific satellites ISO (an infra-red measuring satellite) and SAX (an x-ray measuring satellite) as well as the joint Herschel-Planck mission.
Essential parts of AOCS are sun sensors and reaction wheels.
Cosine Sun Sensor fits in the palm of your hand - image: TNO
TNO’s sun sensors have more than 30 years of flight heritage with 100% reliability, and Bradford Engineering currently provides industrial sun sensor production. They have guided telecom, earth-observation and science satellites in LEO, MEO, GEO, at Lagrange points, and on their way to Mars, Venus and comets. The Dutch legacy continues with the next generation's miniaturization, autonomy, and integration potential. While the new generation of miniature fine sun sensors is prepared for flight, the next-next-generation of micro sun sensors is already being developed. Bradford Engineering also provides Reaction Wheel Assemblies (RWA’s); which cause the satellite body to rotate in the opposite direction of the RWA’s motor due to the induced counter torque.
