MFM MTS Folding Mirror Subsystem

Client: National Institute of Aerospace Technology (INTA)

Year: 2007 – 2008

LIDAX has been involved in the MTS project, an Optical Ground Support Equipment for ESA MIRI (Medium Infrared Instrument) Qualification (James Webb Space Telescope Program)

LIDAX developed for INTA four different Folding Mirror assemblies (FM1 to FM4) to operate at cryogenic environment (25K, 10-6 mbar).

The activities carried out were the following:

Design, Analysis, Manufacturing, electronics & software control, Integration and Qualification tests.

The system had the following main characteristics:

  • Mirrors: golden coated and elliptical apertures 240x176mm
  • Manual tip-tilt adjustment system of 10µrad resolution
  • Mass 5.5-8.4 kg

With the objective of providing MTS with an optical compensation system, two of the mirror assemblies had rotation capability by means of actuators and sensors commanded in closed loop mode. Their performances were as follows:

  • Rotation range ±100 µrad
  • Mechanical Resolution <1.0 µrad
  • Absolute accuracy 10 µrad
  • Repeatability 1.0 µrad

Several development tests were carried out in the program frame at 25K with the following main objectives:

  • To test sensor behavior at cryogenic conditions
  • To check measurement & calibration techniques
  • To test different actuator concepts
  • To test different lubrication types
  • To test actuators’ lifetime

Development test results were considered for final mirror assemblies design.