On ground Testing

CSL is internationally recognized in the qualification/calibration of optical payloads under Space environment since the early 70’s according to the famous sentence “Test as you fly” and, for years, has been an “ESA-coordinated facility”.

T

hese test steps are of prime importance in the development of an instrument or even a complete satellite. After the various qualification campaigns, the tested payload is stamped “ready to be launched”.

Telescopes and space science instruments that have been tested at CSL span the full electromagnetic spectrum, from X-rays to far infrared. Through every specific case, CSL team has gained unique experience and enlarged its testing capabilities to meet a wide range of test conditions and payload dimensions. The specific CSL competencies in test are thermal design and control, structural vibration, cryogenic domain, thermal instrumentation monitoring, optical equipment, and electronics support.

CSL performs various qualifications on satellites, space instruments or units by submitting them to environmental space conditions in a perfect clean environment (ISO7 to ISO5).

Today, the Testing Department operates five thermal-vacuum chambers with volumes ranging from 1 to 170 m³, two shakers (88 to 200 kN) and a number of specialized equipments, all located in a 1 000 m² clean room area.

Several kinds of test activities are performed at CSL premises

• Thermal Balance/Thermal cycling with thermal vacuum chambers (from 1.5m to 6.5m diameter with dedicated thermal system units).

The controlled thermal environment is achieved either by use of LN2/GN2 thermal systems or using one of the two Helium Liquefiers/refrigerators for the cryogenic applications (down to 4.2K).

Most of CSL’s vacuum chambers are equipped with built-in optical benches providing high mechanical isolation compatible with interferometric measurements.

Optical stimuli can be, under thermal vacuum environment, injected on the tested specimen for validating the final optical performance. Dedicated OGSE (Optical Ground Support Equipment) are designed by CSL, installed and used during the test campaign.

• Outgassing tests (with permanent contamination level follow-up)
• Optical Stray-light test at ambient
• Vibration with two separate shakers (88kN and 200 kN)

The specific CSL assets in the test laboratory are

• Hyperclean environment (class 100 – ISO 5)
• Tailored thermal environment from cryogenics (4°K) to hot cases (353 °K)
• Optical oriented design and calibration expertise
• Team flexibility and customer oriented support

CSL can offer a complete Test Service Package

• Review of customer’s specifications
• Review of test feasibility
• Test set-up design and manufacturing
• Test plan and test procedure
• AIV operations
• Instrumentation and data acquisition
• Mechanical, thermal and optical   expertise
• Testing
• Measurement of instrument performance
• Result analysis
• Reporting

A typical space qualification sequence is

• Arrival at CSL and unloading
• Cleaning and entering in AIV clean area
• Integration and preparation phase
• TV test
• Integration and instrumentation
• Mechanical test
• Dismounting and packing
• Departure and final reporting