ENVIRONMENTAL TESTS

The space environment has different physical phenomena. The influence of such physical phenomena in a specific space mission depends on the satellite’s orbit.

Satellites are built with electronic a mechanical components. Before the satellite will be send into space engineers must be sure that the satellite will be able to survive in space and comply with the mission objectives.

BURN-IN TEST

In a Burn-In Test new manufactured products will be stressed in order to force the reproduction of certain failures under specific load capacities. The intention is to detect particular components that would fail as a result of the initial, high-failure rate portion of component reliability. If the burn-in period is made sufficiently long and artificially stressful, the system can then be trusted to be mostly free of further early failures once the burn-in process is complete. Weak components would fail during the Burn-In time. Detecting weak components would prevent premature failure, infant mortality failure, or other latent defects. The Burn-In Test for electronic components is achieved at high temperatures and elevated voltages. This process is called „heat soaking“. During the Burn-In Test the devices are in operation and will be monitored constantly.

For the Burn-In Test the standard MIL-STD-883 Method 1015.10 will be used.

THERMAL VACUUM CYCLING TEST

Electronics in space must be adapted to the space conditions and it is necessary to prove it simulating the space environment. In space are not air only vacuum. In vacuum the generated heat from the components can be only irradiate or conducted to a cooling element. The vacuum chamber is a cylinder and inside a satellite can be fixed. The air from the chamber will be evacuated until the required vacuum quality is reached. Through a window Xenon lamps will simulate the Sun. On the back part of the chamber a vessel cover the back side. This vessel will be filled with liquid Nitrogen or liquid Oxygen. The filled vessel represents the cold empty space. It is possible to rotate the satellite model and prove the solar energy gathered on each selected position. The temperature of the DUT will be increased with heaters installed on the chamber walls. It is also possible to warm up the DUT with a heater installed on the platform where the DUT is mounted.

In order to determine if objects can withstand temperature changes under vacuum a thermal cycling test under vacuum will be achieved following the standard ECSS-Q-ST-70-04C (Thermal testing for the evaluation of space materials, processes, mechanical parts and assemblies).

OUTGASSING TEST

Materials have the particularity to release gases by increasing the temperature. In a space system such phenomena will create an artificial atmosphere or contaminate sensible parts like lenses. For this reason it is necessary to evacuate all volatile gases from all materials used in the satellite. This process is called Outgassing and this process is necessary to achieve for all materials and components. The Outgassing can be done in a vacuum chamber.

For the outgassing test the standard ECSS-Q-ST-70-02C (Thermal vacuum outgassing test for the screening of space materials) will be applied.

VIBRATION TEST

Satellites will be launched into space with satellite launchers which are a giant rocket and for its nature the rocket engine generates enormous power and also vibrations. The vibrations have different origins and characteristics.  The arising vibrations have a frequency range from 1 to 2,000 Hz. The origin is sinus harmonic and random noisily. For the first a sinus signal will simulate the vibrations and a random signal will simulate the noisy signal. There a two types of facilities. For low frequencies a hydraulic system will be used and for high frequencies a electrodynamic system will be used. The shaker is built with a vibration motor which is a motor with an asymmetric weight on the axis. The size of the facility depends of the DUT’s weight. The DUT will be fixed in the shaker and control sensors are installed on the shaker self and further sensors are installed on the DUT to measure the real vibration on the DUT.

The Vibration Qualification Test will be achieved following the MIL-STD-883 Mechanical tests with the methods 2005.2, 2006.1, 2007.2 and 2026.

For specific flights the launcher User Manual will be used for the proper qualification.

SHOCK TEST

The standard ECSS-E-HB-32-25A (Space Engineering – Mechanical Shock Design and Verification Handbook) supports the development, design, analysis and verification of spacecraft structure in relation to shock environment. It covers the shock inputs to equipment and sub-systems inside a satellite structure and the verification to ensure a successful qualification.

The Shock Qualification Test will be achieved following the MIL-STD-883 Mechanical tests with the method 2002.3.

For specific flights the launcher User Manual will be used for the proper qualification.