CFRP structure for optical payload v1.pptx

Literature

1. CFRP Structure for Optical Payload Introduction to payload requirement and sample requirement

2. Introduction Following two major parts in payload are made of CFRP Cylinder (along with secondary mirror spiders) Baseplate (with Al honeycomb)

3. Optical Payload Structure SMA mount I/F ring Spider (CFRP) Primary mirror Secondary Mirror Assembly Tertiary mirror mount panel Tertiary mirror Cylinder (CFRP)

4. CFRP Cylinder – Salient Features Cylinder covers primary mirror and secondary mirror It also provide structural support for secondary mirror. Secondary mirror assembly (SMA) will be mounted on SMA mount I/F ring at top of cylinder. Secondary mirror should be co-axially aligned with primary mirror. Spiders and SMA mount I/F ring will be integrated part of cylinder. It may be bonded or bolted as per design. Spiders will be made of CFRP and SMA I/F ring material can be CFRP or Invar. 0.005mm flatness will be required at cylinder mounting Interfaces as well as secondary mirror interface. 0.05mm parallelism will be required at secondary mirror interface with respect to cylinder mounting interface.

5. CFRP Cylinder - Requirements Cylinder will be exposed to space environment; it need to survive space environment (Temperature difference and solar radiation). TML 0.1, CVCM 0.01% Lower Coefficient of thermal expansion (CTE)  is required to maintain axial dimensional stability of secondary mirror. Lower Coefficient of moisture expansion (CME) is required to avoid moisture expansion while it is stored or integrated with payload. CTE test will be carried out at temperature range of -20 C to +60 C. Cylinder is subjected to structural and vibration load (Sine and Random Vibration) during launch. It is subjected to quasi-static structural load of 25g in axial direction and 15g perpendicular to axis. All environmental data will be provided for design of final product along with drawing of required structure.

6. CFRP Baseplate – Salient Features Material: Aluminum honeycomb panel with CFRP faceplate on both sides. All payload components and subsystems will be mounted on baseplate. Optical payload is subjected to structural and vibration load (Sine and Random vibration) during launch and baseplate will provide mounting interface with BUS. All environmental data will be provided for design of final product along with drawing of required structure. Required material properties will be shared. 

7. Sample preparation To test CTE and CME values of material

8. Tests to be carried out at AEG Coefficient of thermal expansion Coefficient of moisture expansion

9. Tests to be carried out at ACPL Tensile test Bending test Shear test Flexural strength test Delamination test