The Cryogenic Star Tracking Attitude Regulation System (CSTARS)

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1 The Cryogenic Star Tracking Attitude Regulation System (CSTARS) Michael Zemcov Assistant Professor The Rochester Institute of Technology The Jet Propulsion Laboratory Northeast Regional Space Grant Meeting October 7, 2016 Closing in on the Cosmological Model Aspen, CO M. Zemcov, March

2 CCD vs CMOS CCDs are the high-end imaging device of choice at optical wavelengths. Though they perform well in a variety of applications, because they require charge transfer to read out, they have various drawbacks. One of these is electron freeze out below about 200K; charge transfer becomes increasingly inefficient and no longer functions at cryogenic temperatures. Because they address each pixel independently, CMOS devices do not suffer from this effect. For the past few decades, CMOS technology development lagged that of CCDs, but due to industrial interest CMOS imaging technology has caught up.

3 Natively Cryogenic CMOS Do Work CAMERA CRYOGENIC DETECTOR PACKAGE 77 K CRYOSTAT Tests in the lab show that, with an analog output, CMOS chips work well down to at least 77 K (and potentially to 10K).

4 Relevance to NASA: Cryogenic CMOS Applications in Space Cryogenic Payloads in Earth Orbit CubeSats in Deep Space Unregulated imagers in the outer solar system Can we prove out this technology in a space environment?

5 Cryogenic Star Tracking Attitude Regulation System (CSTARS) USIP2015 to the rescue! A simple demonstration would be to use a cryogenic CMOS device in a sub-orbital application. This would advance TRL from 4 to 7. Wrote a proposal, and (eventually) NASA went forward with it, with funding starting May From Left to Right: Project Manager: Hyun Won, International Business Team Leader: Kevin Kruse, B.Eng./M.Eng. EE Electrical Engineer: Benjamin Bondor, B.Eng. EE Fast Forward Intern: Keegan Evans, B.S. Physics Software Engineer: Poppy Immel, B.S./M.S. Comp. Math & CS Mechanical Engineer: Christian Pape, B.Eng./M.Eng. MET & MMSI Instrument Scientist: Matthew Del Favero, B.S. Physics PI/Faculty Mentor: Dr. Michael Zemcov Not Pictured: James Parkus (ME), Chi Nguyen (GS Mentor), John Hill, Philip Linden (UG Alums), Dr. Dorin Patru, Dr. Mihail Barbosu (Faculty Mentors).

6 Cryogenic Star Tracking Attitude Regulation System Cooled CMOS detector captures images, which are then used to find star images and do a control loop on current position. Will fly prototype on SubTech-7 (PI Hesh) water recovery system technology demonstration flight in a Black Brant IX from WFF.

7 Instrument Parameters Parameter Operating Temperature Frame Rate Pixel Size Value 77 K 10 Hz 15 μm x 15 μm 21 x 21 arcsec 2 Number of Pixels 1024 x 1024 Aperture Spot Size (FWHM) Filter Center Filter Width Field of View Native Pointing Drift 71 mm 35 arcsec 650 nm 345 nm 36 sq. deg. 6 arcmin/s

8 CSTARS Mechanical Design

9 CSTARS Electronics

10 CSTARS Flight Plan Two main target fields: 24 Lyncis (RA: 07h 43m 0sec, Dec: +58deg 42' 37") HIP (RA: 05h 58m 46sec, Dec: +60deg 22' 47")

11 CSTARS Star Tracking Algorithms

12 Education and Outreach Activities In this program, we are eager to get students out of the classroom and into the laboratory. In summer 2016, we had two high school students working in the laboratory on various subsystems. We will be searching for more for summer CSTARS has already generated two news articles (including engineering.com) and a proposed magazine article in Cold Facts (Cryogenic Society Glossy). Have been involved with USIP sounding rocket working group to help teach other teams based on our experience. Will work with RIT&WFF to show launch in a public event. Will also work on an ImagineRIT display for May 2017.

13 A Real-Life Application Over 4 flights, CIBER-1 instruments see astrometric drifts of ~0.2 /s which are not seen in the sidelooking ST-5000 system, about 2x spec. DT CIBER-1 Achieved This is thought to be due to differential thermal expansion of the ~2m of rocket skin between the ST-5000 mechanical reference and the CIBER telescope boresight reference.

14 CIBER-2 Design CIBER Collaboration (2014)

15 CSTARS-2 Hardware Have designed a 500 nm periscope style pickoff camera. YAN[deg] fov for optical design light cone (half angle1.7deg) 1.25 Footprint of CCD effective pixels to the sky XAN[deg] Note that this closup view is from the following 3D CAD data : GE _closeupviewForSHTdesign.iges GE _closeupviewForSHTdesign, Feb. 1 st, 2013, Genesia Corporation STT lens design & structure design are tentative. Offset by some millimeters will be possible to secure the clearance for the shutter. G1 lens element for imagers. This shape and position are only tentative, but I will revise the design as this lens element does not move forward. In case the shutter is installed behind the pick off mirror for STT, I wish the shutter can be installed in this clearance.. Is it possible? This barrel for G1 is only tentative. I will revise the design as the surface indicated by the arrow does not move forward.

16 And Into the Future Two students already have secured internships with SpaceX. Given typical undergraduate student lifetimes, I expect the ultimate number of UGs involved in this program to double. It is likely this project will feature in several M.Eng./Ph.D. theses. Foresee several technical papers published in peer-reviewed journals coming from this work. Commercialization? Will have demonstrated a cryogenic star tracking system for orbital applications. Technology for CubeSats and the outer solar system.

17 Summary CSTARS is a UG-lead project to build a star tracking camera for sub-orbital applications. Students have designed and fabricated all systems, and will integrate and fly the payload in the coming months. A second flight will prove out the star tracker, and yield another tool in NASA s suborbital technology toolbox. More broadly this technology has broad applications for NASA and elsewhere. THANK YOU