The different RSU models

The Euclid VIS shutter unit (RSU) is not directly built as a flight unit, but a number of preliminarily models are constructed in advance in order to progressively test the robustness and the maturity of the design.
According to the standard practices for the construction of flight hardware and the specific requirements of the Euclid VIS instrument, the following RSU models are being built:
  • The Engineering Model (EM)
  • The Thermal and Structural Model (STM)
  • The Bread-Board Model (BM)
  • The Qualification Model (QM)
  • The Flight Model (FM)
  • The Flight Spare (FS).
Here we present and discuss the EM model, delivered to the VIS institute lead (MSSL - UK) at the end of November 2015.

The Engineering Model

The EM is mainly built to test all the RSU electrical interfaces and comply to the following build standard:

  • Electronics flight standard except for parts. Commercial parts have to use the same technology and same supplier as the FM parts
  • Mechanisms have to be electrically representative of the FM for what concerns the electrical actuators and sensors

The RSU EM consists mainly of the following main sub-elements:

  1. Base Plate
  2. Support Bracket
  3. Stepper Motor Assembly
  4. HDRM DC Actuator
  5. HDRM Thermistor (4-wire PT1000)
  6. Connector Support Bracket
  7. Micro-switches (11HM1) (4 units for the primary drivetrain + 2 units for the HDRM = 6 units)
  8. Micro-switch support brackets
  9. 2 Main Drive Thermistors (4-wire PT1000)
  10. Connectors
  11. A Harness connecting those connectors to the electrical components, representative of the foreseen FM design in terms of cable lengths, wire gauges and shielding
  12. A set of handles to carry and move the EM
  13. An M4 grounding point

The figures below provide a schematic view of the EM model

Sketch of the RSU EM model. Details of the different parts are given in the numbered list above (credits: APCO Technologies).


We provide below some pictures of the RSU EM model, as delivered to MSSL (UK) at the end of november 2015.

A few pictures of the RSU EM model. From top to bottom: the EM EGSE (Electrical Ground Support Equipment - used to operate the main motor and the HDRM motor), EM front side, EM front side zoom out, EM side view, EM top view (credits: APCO Technologies)