1. STSAT-3 UN BSSW, June 2008 KASI Compact Wide-Field Survey IR Space Telescope Design Wonyong Han Korea Astronomy & Space Science Institute (KASI)

2. STSAT-3 UN BSSW, June 2008 KASI

3. STSAT-3 UN BSSW, June 2008 KASI - Korea Sci & Tech Satellite (STSAT) began 1999 - Korea Sci & Tech Satellite (STSAT) began 1999 - FIMS : KASI developedFIMS,Main Payload of STSAT-1, - FIMS : KASI developed FIMS, Main Payload of STSAT-1, in collaboration with KAIST & UC Berkeley in collaboration with KAIST & UC Berkeley - STSAT-1 (FIMS) Launched in 2003 - STSAT-1 (FIMS) Launched in 2003 - FIMS Science Results were Published on ApJL in 2006 - FIMS Science Results were Published on ApJL in 2006 - STSAT-3 Program started in 2007 - STSAT-3 Program started in 2007 - KASI Proposal, MIRIS was Chosen as Main Payload - KASI Proposal, MIRIS was Chosen as Main Payload - MIRIS is small wide-field IR Space Telescope - MIRIS is small wide-field IR Space Telescope [ M ulti-purpose I nfra- R ed I maging S ystem ] [ M ulti-purpose I nfra- R ed I maging S ystem ] Introduction

4. STSAT-3 UN BSSW, June 2008 KASI FIMS Heritage ApJL, 2006, Vol 644, Special Issue - First results from the FIMS Mission - 9 papers published including Instruments & System Performances Total diffuse intensity map of the sky for the SPEAR/FIMS L-band (1360-1730 A) observations. Evident features include the Galactic plane, the Sco-Cen association, and the LMC.

5. STSAT-3 UN BSSW, June 2008 KASI MIRIS : Scientific Goal (1/3) Galactic Plane Survey (1/2) Origin of the Warm Ionized Medium (WIM) –Challenge to the current paradigm of the Ionization theory –Test the effect of Dust scattering for the WIM observation Observation : Pa  survey –Pa  (MIRIS) vs. H  (Ground-based) : Scattering difference Hαmap from a ground-based survey

6. STSAT-3 UN BSSW, June 2008 KASI Scientific Goal (2/3) Galactic Plane Survey (2/2) Physical Properties of Turbulence in the Galaxy –Survey the physical parameters of turbulence in the Galaxy –Derive Magnetic field strength from the structure characteristics of turbulence Observation : Pa  survey –Pa  (MIRIS) vs. H  (Ground-based) : Extinction difference Measurement of the turbulence structure Turbulence model

7. STSAT-3 UN BSSW, June 2008 KASI Scientific Goal (3/3) Cosmic Infrared Background (CIB) Observation Origin of the Near-IR CIB –Test the hypothesis of the Pop III origin –Confirm the degree-scale fluctuation suggested by IRTS & AKARI and reveal its nature Observation : I & H-band –I-band (no Pop III) vs. H-band (Pop III expected) Matsumoto et al. 2005 Spectral bump suspected to be redshifted from the Pop III Ly-cutoff Degree-scale fluctuation in the power spectrum from IRTS

8. STSAT-3 UN BSSW, June 2008 KASI MIRIS System Design

9. STSAT-3 UN BSSW, June 2008 KASI STSAT-3 Layout Space Observation Camera Earth Observation Camera Secondary Payload, COMIS Sun Avoidance = ±90 degree Earth Avoidance = ±30 degree Sun Avoidance = ±30 degree Star Tracker

10. STSAT-3 UN BSSW, June 2008 KASI Space Observation Camera (SOC) MIRIS Layout Controller box Nadir Flight direction X(Roll) Z(Yaw) Y(Pitch)

11. STSAT-3 UN BSSW, June 2008 KASI MIRIS Specifications Space Obs. Camera (SOC)Earth Obs. Camera (EOC) Wavelength0.9 – 2 um3 – 5 um Aperture80 mm100 mm Focal ratiof/2f/5 Pixel FOV51.6 arcsec Detector FOV3.67 o x 3.67 o Ground pixel size42 m @700km Swath width13.4 km @700km SensorTeledyne PICNICi3 system FilterFilter Wheel (6 filters)Band pass filter Telescope Temp180-200 K (passive cooling)300 K Sensor Temp77 K PerformanceMTF > 60%MTF > 20%

12. STSAT-3 UN BSSW, June 2008 KASI MIRIS Operation Concept ModeTest (3 months)1 st Year2 nd Year Bus Test 10 orbits/day (1 month) (if needed) Space Observation -Galactic Plane -Cosmic Background -Calibration (1 month) 4 orbits/day 2 orbits/day 6 orbits/day 2 orbits/day User time (if needed) Earth Observation (1 month) 2 orbits/day Regular Test & Emergency Observation 6 orbits/day Ground Contact4 orbits/day

13. STSAT-3 UN BSSW, June 2008 KASI SOC Layout Cooler Lens Detector Baffle Radiator

14. STSAT-3 UN BSSW, June 2008 KASI SOC Optics

15. STSAT-3 UN BSSW, June 2008 KASI SOC Filter System Purpose IDCWL (um)FWHM (um) Cosmic Infrared Background I1.050.3 H1.60.8 Galactic Plane Survey Pa alpha1.8760.0188 Pa alpha cont 11.840.0184 Pa alpha cont 21.920.0192 Dark & ShutterBlank

16. STSAT-3 UN BSSW, June 2008 KASI Performance of SOC Optics Field (degree) RMS spot size (um) 0.00012.4 0.89510.8 1.79012.0 2.61224.0

17. STSAT-3 UN BSSW, June 2008 KASI SOC Structure (1/2)

18. STSAT-3 UN BSSW, June 2008 KASI SOC Structure (2/2)

19. STSAT-3 UN BSSW, June 2008 KASI Passive Cooling for SOC (1/2)

20. STSAT-3 UN BSSW, June 2008 KASI Passive Cooling for SOC (1/2) Temperature profile during one orbit (1) The telescope can be cooled below the goal temperature of 200K (2) The detector can be cooled below the goal temperature of 80K

21. STSAT-3 UN BSSW, June 2008 KASI MIRIS Eelectronics

22. STSAT-3 UN BSSW, June 2008 KASI MIRIS Electronics Box

23. STSAT-3 UN BSSW, June 2008 KASI SOC Electronics Q1Q2 Q3Q4 AMPADC PATTERN GENERATOR 4 channel VIDEO Siganal Processing IMAGE DATA DECODER AMPADC AMPADC AMPADC FPGA MEMEORY IMAGE BUFFER CONTROL COMMAND MMS GSE DSP UNIT PICNIC 256  256 ARRAY BIAS CLOCK FIFO SOC READOUT UNIT

24. STSAT-3 UN BSSW, June 2008 KASI SOC Detector - HgCdTe Astronomical Wide Area Infrared Imager (PICNIC) - 256  256 IR FPA HgCdTe/Al 2 O 3 (MBE) ParameterSpecificationGoal Format256  256 Pixel Pitch (μm)40 Fill Factor90 Quantum Efficiency(77K) @2.3 μm55%75% Long wavelength cutoff (μm)2.5 Short wavelength cut on (μm).9 Read noise: multiple sample (e - @ 77K)< 40< 20 Dark current (e-/s @ 77K)< 2< 0.2 Well capacity(e-, V b = 0.5V)150,000200,000 Yield(working pixels)> 95%> 99% Temperature77K

25. STSAT-3 UN BSSW, June 2008 KASI MIRIS Operation

26. STSAT-3 UN BSSW, June 2008 KASI Plan for Galactic Plan Survey 6°

27. STSAT-3 UN BSSW, June 2008 KASI Plan for Galactic Plan Survey

28. STSAT-3 UN BSSW, June 2008 KASI Plan for the CIB Observation 10 o x10 o deep field @ NEP 50%(1.84 o ) overlap mosaic for uniform sensitivity Best in October & November

29. STSAT-3 UN BSSW, June 2008 KASI Thank you whan@kasi.re.kr