1 The slides in this collection are all related and should be useful in preparing a presentation on SIM PlanetQuest. Note, however, that there is some redundancy in the collection to allow users to choose slides best suited to their needs. Some slides appear to be duplicates (e.g. “Siderostat mirror points over field of regard”). These slides show animation when viewed rapidly in succession.

2 Siderostat Assembly (an old view) A “ Siderostat ” is a flat steering mirror that keeps the line of sight of telescope STAT ionary in SID ereal space. As the platform moves around, the Sid compensates. It also allows the line of sight to be aimed over a region of sky without moving the platform or the telescope. Telescope line of sight is rotated about two orthogonal axes centered on the front face of the Sid by a gimbals assembly. A corner cube retroreflector will also be mounted with its vertex here (see slide later on)

3 Siderostat Mirror Points Over Field of Regard Mirror Normal Incoming Starlight Telescope Primary Mirror Siderostat Mirror

4 Siderostat Mirror Points Over Field of Regard Sid aimed upward Telescope Primary Mirror Incoming Starlight

5 Siderostat Mirror Points Over Field of Regard Sid aimed downward Telescope Primary Mirror Incoming Starlight

6 Siderostat Mirror Points Over Field of Regard Telescope Primary Mirror Siderostat Mirror moves only 7.5° (i.e. ±3.75°) 15° Field of Regard (FOR) on the sky

7 Guide Star Steering Optical System Light passing though one conjugate point … … will pass though other conjugate point For SIM’s telescopes, we place Fast Steering Mirror and Corner Cube (CC) at Conjugate Points. This keeps the Internal Metrology Beam centered on CCs as the Fast Steering Mirror moves starlight with pointing changes. SIM Compressor Conjugate Points: Corner Cube (CC) FSM

8 Guide Star Steering SIM Compressor Corner Cube (CC) FSM Optical System Conjugate Points: Light passing though one conjugate point … … will pass though other conjugate point For SIM’s telescopes, we place Fast Steering Mirror and Corner Cube (CC) at Conjugate Points. This keeps the Internal Metrology Beam centered on CCs as the Fast Steering Mirror moves starlight with pointing changes.

9 Guide Interferometer Pointing Fast Steering Mirror (FSM) used to steer line of sight for Guide Compressors Corner Cube (CC) and FSM at Conjugate Points Fast Steering Mirror Primary Mirror Secondary Mirror Tertiary Mirror Pathlength dither optic Portion of CC used by Internal Met

10 Guide Interferometer Pointing FSM used to steer line of sight for Guide Compressors CC and FSM at Conjugate Points Portion of CC used by Internal Met Fast Steering Mirror Primary Mirror Secondary Mirror Tertiary Mirror Pathlength Dither Optic

11 Guide Interferometer Pointing FSM used to steer line of sight for Guide Compressors CC and FSM at Conjugate Points Portion of CC used by Internal Met Fast Steering Mirror Primary Mirror Secondary Mirror Tertiary Mirror Pathlength Dither Optic

12 Beam footprints on retroreflector incoming beam outgoing beam intermediate bounce All beam footprints must lie within the retroreflector and clear all edges, with margin. Triple Corner Cube (TCC) Arrangement

13 Here, we use only two of the three corners Double Corner Cube (DCC) on Face of Siderostat

14 One Science Interferometer Compressor High-Bandwidth Optical Delay Line Astrometric Beam Combiner Siderostat Low-Bandwidth Optical Delay Line

15 Add One Guide Interferometer First Guide constrains one degree of freedom

16 Add a Second Guide Interferometer Second Guide constrains an orthogonal degree of freedom Roll about baseline does not affect measurements (to first approximation)

17 Add External Metrology Subsystem External Metrology ties the science baseline to the guide baseline

18 External Metrology Subsystem Alone External MET Beam Launchers

19 Add Precision Support Structure Precision Support Structure (PSS) connects and supports elements stably

20 Optical Delay Lines (ODLs) Guide Corner Cube Science Compressor Guide Compressor External MET Beam Launchers External Metrology Beams Instrument Configuration Guide Interferometer Fields of View Science Interferometer Field of Regard Astrometric Beam Combiners (ABCs)

21 Top View Science interferometers maintain preferred translational symmetry Guide interferometers have mirror symmetry

22 Top and Side Views

23 Overall Configuration (deployed) Solar Array HGA LGA Spacecraft COL Bay 2 COL Bay 1 PSS Truss Star Tracker Siderostat And DCC Compressor TCC ABCs (3) ODLs

24 SIM Configuration Stowed Spacecraft Deployed PSS truss COL bay enclosures Vibration isolators Contamination covers MLI covering of PSS truss and COL bay enclosures not shown

25 Stowed in Fairing