FalconSAT-7 Deployable Solar Telescope Lt Col Brian Smith United States Air Force Academy Space Physics and Atmospheric Research Center 5 August 2014 Distribution A: Approved for Public Release, Distribution Unlimited 1
Program Background Problem: Large optics are massive FS-7 Solution: Deployable membrane optics Photon sieve diffractive optic Surface requirements relaxed by 100 times Narrow-band due to chromatic aberration Diffraction-limited imaging performance Mass of Satellite (kg) STARE 4kg mass ~0.05m diameter FS-7 4 kg mass 0.2m diameter Mass vs. Diameter of Space-Based Imaging Systems Diameter of Primary Optic (m) Desirable direction Scaled-up to ESPA-class 180 kg mass 1 m diameter 2
FS-7: Deployed Lanyard Stowage Tree Photon Sieve Lower Hexapod Lanyard Tensioning System Deployed Ribbon Radio Upper Hexapod Lanyard Tensioning System Photon Sieve Stowage Canister Note: side panels are missing for visibility to interior 3
Ops Mission Success Criteria Education: USAFA Cadets and AFIT Grad Students Deploy photon sieve: Full extension and spread of pantographs Image sun: Photons through sieve, captured by camera, transmitted to ground, recognizable features (e.g., edge of sun) Characterize image performance: Comparison of multiple image settings (Integration time, focus, binning, analog/digital gain) Flight heritage on photon sieve: -X Threshold images once Objective images on day 30 -Z -Y 4
FS-7 Mission Architecture Spacecraft Dimensions Total S/C mass 4.0 kg, NTE Colony II bus Mass: 2.3 kg Size: 3U CubeSat, 10 x 10 x 34 cm Peregrine payload Mass: 1.695 kg NTE Size: 1.5U, 10 x 10 x 15 cm stowed Mission Schedule FM Delivery: Start of FY16 (Oct 2015) Launch: FY16 Launch Vehicle Options Falcon9 Heavy/P-POD (Provider: STP) Orbit: Altitude: 720km; Inclination: 24 Possible ALASA Launch Orbit: TBD Mission Operations USAFA virtual ground station MC3 university network Artist s Concept 5
Technology & Development Freefall test of deployment system successful Proven QM electronics and software Payload fits in C2B! Deployment System Melt wire electronics Optical Platform Payload Electronics Space Test Program sponsored free fall deployment system test nrwa EM C2B 6
Deployment Repeatability Stow Deploy Measure Tip Positions Average over 5 deployments Determine tiptilt Diffraction limited Tip-tilt of 0.1 degrees EM used to develop process QM being measured Coordinate Measurement Machine 7
Photon sieve design 0.2m diameter, f/2 sieve, imaging at H-alpha (656.45nm) 2.5 billion divots 2-280 m, randomly oriented in azimuth Etched in 28 micron thick Kapton (30% efficiency)
Optical results Images of the PSF and test target taken by sieve held by assembly fixture before released from tip holders: Able to resolve element 6 group 6, diffraction limit for this optical system 9
Ground Solar Telescope Optical System description: 90 mm glass PS (same design as flight master), F# 5. Secondary optics the same as for FalconSat- 7: collimating lens, narrowband (0.1 A) filter, focusing lens Thorlabs CMOS camera (DCC1545M) Tests in the lab show diffraction limited performance 10
Notional Program Schedule FY 14 FY 15 FY 16 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q Today Design Opto-mech model Dashboard* Build QM #1 Refurb QM #2 Flt Payload Bus Recall FS-7 EM Repeatability Rip/snag QM P/L EM Bus fit/function FM P/L Flt Bus Functional Flight Delivery Launch TBD Test QM Repeatability Functional Testing Environments Qual Model * User friendly operational control of satellite payload Environments Sub-support complete Flight Model The views expressed are those of the author(s) and do not reflect the official policy or position of the Department of Defense or the U.S. Government
Conclusion/Discussion FS-7 Team made substantial progress on QM QM testing Integration Testing at USAFA (June 2014) Environmental Testing at AFIT (July 2014) FM build FY 2015 Launch FY 2016 FalconSat-7 big telescopes on little satellites Artist s Concept 12