Jahresbericht 08 - PMOD/WRC
Jahresbericht 08 - PMOD/WRC
Jahresbericht 08 - PMOD/WRC
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Space Experiments<br />
Silvio Koller and Dany Pfiffner<br />
PREMOS<br />
The PREMOS experiment, a payload unit aboard the<br />
French micro satellite PICARD, reached its final development<br />
phases in 20<strong>08</strong>. PREMOS contains two<br />
PMO-6 type absolute radiometers and three filter<br />
radiometers, measuring three visible- and three UV<br />
wavelength ranges. The launch of PICARD is planned<br />
for the end of 2009.<br />
The Proto Flight Model was assembled during the spring<br />
months. The experiment contains five instruments, cover<br />
mechanisms for each of them and auxiliary electronics,<br />
such as: power converters, instrument control electronics,<br />
data acquisition and data interfaces.<br />
Following internal functional tests at hard- and software<br />
level, the required environmental tests were carried out.<br />
Electro-magnetic compatibility tests were performed at the<br />
“EMC Testlab”, Zürich, Switzerland. Electromagnetic susceptibility<br />
was investigated, as well as emission levels determined.<br />
The thermal vacuum test took place at<br />
<strong>PMOD</strong>/<strong>WRC</strong>. It consisted of a burn-in test under vacuum<br />
at elevated temperature and four times cycling between<br />
the minimum and maximum qualification temperature<br />
(-40°C to +60°C). Afterwards the experiment underwent<br />
vibration tests at the University of Berne, Switzerland. During<br />
these tests resonance frequencies of the experiment<br />
are measured and vibrations with a random spectrum as<br />
input simulate conditions during the satellite launch. The<br />
measured accelerations are then compared with previously<br />
calculated values in order to verify the structural model.<br />
Figure 1. PREMOS Thermal Balance Test. The experiment is placed in a<br />
vacuum chamber and wrapped with MLI (Multi-Layer Insulation). Several<br />
temperature sensors are placed on different locations of the instrument to<br />
provide measurement points for verification of the thermal model.<br />
Instrument Development 15<br />
PREMOS was delivered to CNES (Centre Nationale d’Éspace<br />
Spatiale), the French Space Agency, in July. Several incoming<br />
inspection tests were carried out at CNES. Its<br />
cleanliness was screened, power consumption and functionality<br />
were verified and magnetic moment measurements<br />
were conducted.<br />
PREMOS was shipped to IAS, Paris for the Thermal Balance<br />
Test where the instrument was set-up in a vacuum<br />
chamber under different thermal environment cases. Measured<br />
absolute temperatures, temperature distributions and<br />
time constants then allowed cross-correlation with the<br />
PREMOS thermal model.<br />
Requested documentation was prepared in parallel. A<br />
“Point Clé”-Meeting was organized by CNES in order to<br />
compare requirements, performed tests and verification<br />
status during the official delivery of PREMOS. In the last<br />
months of 20<strong>08</strong> PREMOS was integrated on PICARD.<br />
Figure 2. Launch of ATLANTIS STS-122 occurred on schedule on<br />
February 7, which turned out to be a really nice day with clear skys.<br />
It brought the experiment SOVIM to the ISS.