1. M1M3 Cell and Support System

2. M1M3 on Telescope 2 Location of the M1M3 Cell and Mirror on the Telescope

3. Mirror supported on Cell 3 Mirror Wt: ~17000 kg Total Wt (Mirror + Cell + Internals): ~53000 kg Key systems:  Gravity support and figure control force actuators  Hardpoint Struts to locate mirror  Thermal control via cooling air injection into mirror cores

4. Pneumatic Support Actuators 4 React gravity force and Provide figure correction force 112 Dual axis actuators 44 Single axis actuators Force Range: 2500 N axial, 2000 N lateral Non-repeatable error: +/- 0.5N RMS max Do not locate mirror Piston Style pneumatic cylinders Pressure servo valves Loadspreader bonded to mirror back face Inner Loop Controller monitors load cell signal and adjust servo valves Load Cells measure force produces

5. Mirror Hardpoint Struts 5 Locate mirror with respect to Cell Hexapod configuration – provides kinematic adjustment in all 6 DOF Mechanical breakaway mechanism to prevent excessive force on mirror Stiffness: 100+ N/mm Control system adjusts support actuators to maintain zero force through hardpoints.

6. Mirror Thermal Control Units 6 97 units pull air through liquid cooled heat exchangers and pressurize cell interior. Nozzle direct cooling air from cell into each mirror core through vent holes in the back face. Ejected air from each core is pulled back through the thermal control units completing the cycle. Temperature uniformity is augmented by trimming resistor heaters in each unit.