Progress Report Geo-CAPE Coastal Ecosystem Dynamics Imager (CEDI) IRAD Repackaging Study Jason Budinoff / GSFC Cathy Marx / GSFC May 12, 2011

2 Coastal Ecosystem Dynamics Imager (CEDI) Block Diagram – IDL Baseline Scan Mirror Primary Mirror Telescope “Aft” Optics External Baffle Enclosure Optical Bench Band 2( nm) SIRU Star Trackers (3) (orthogonally mounted) Aperture Cover (closed during solar cal) Band 1 ( nm) SWIR Band Slit MCT H2RG 2Kx2K HyVISI TCM8050A Custom 1K x 2K HyVISI TCM8050A Custom 1K x 2K Calibration Source Thru-hole Aperture Door Launch Lock Detectors Volume m 3 Mass kg Power W

I n t e g r a t e d D e s i g n C a p a b i l i t y / I n s t r u m e n t D e s i g n L a b o r a t o r y GEO CAPE Study Week: 1/25 – 1/29/10 Presentation Delivered: Jan 29, 2010 Use or disclosure of this data is subject to the restriction on the title page of this document Mechanical Systems, p Final Aperture & Calibration Covers Opened 2-Sided Diffuser plate Scan mirror mechanism Solar Calibration View Lunar Calibration & Nadir Science Views

Why? Desire to reduce instrument volume to allow payload to be hosted on other missions “Minimally acceptable scientifically viable mission”….help to define this from the bottom up GEO-CEDI (IDL) at 7.5m 2 too large to allow hosting on some platforms Study will evaluate architecture & packaging trades to reduce volume.

Volume Comparison GEO-CEDI (IDL) 7.5 cubic meters GEO-MDI 15.3 cubic meters GEO-CEDI (IRAD) 4 cubic meters?

Trade Space The merit function is lowest volume, then lowest cost. Several parameters will be traded: 1.Alternate optical packaging, Eff F/#, folding, etc. 2.Reduce gimbal size, alternate gimbal architectures 3.PPS / Jitter control implementation 4.Alternate calibration schemes 5.Primary Mirror scaling Some parameters will not be traded: 1.Instrument architecture (Offner Relay slit spectrograph) 2.Spectral range and channel count

Gimbal Traditional elevation over azimuth type is baseline Evaluate flexure suspension XY scanner; analogous to large, “slow” steering mirror Evaluate transmissive cal with XY scanner only –Trade large air gap voice coils vs. limited angle torque actuators

Alternate Optical Packaging Faster telescope “out of plane” folding options to enable more space efficient packaging –Additional fold optics required –Additional optics (periscope/K mirror) may be required to maintain slit orientation after folding Current “IDL” layout shown

Out of Plane Layout Channel 1 HyViSi ROIC 345 – 600 nm Channel 3 H2RG nm Channel 2 HyViSi ROIC nm 120mm FSM in periscope Slit channel 1+2 Slit channel 3

Calibration Specular calibration –IDL concept has deployable calibration assembly, and required 3 mechanisms for 2 specular targets Transmissive calibration? Can we reduce number of calibrators? Diffuser Plate Select Mechanism Double sided diffuser Cover Mechanism Launch Lock

Precision Pointing System (PPS) Add the JHU/APL PPS which utilizes FSM+star tracker+inertial reference (gyro) system to increase S/N, cancel S/C and self jitter –Coupled with scanning gimbal How do I get smaller by adding more components?

Alternate Layout

Future Work Complete mechanical sizing trade Add structural, thermal, optical bench detail GEO-CEDI (IDL) 7.5 cubic meters GEO-MDI 15.3 cubic meters GEO-CEDI (IRAD) <7.5 cubic meters