Ball Aerospace Scalable Configurable Cryocooler Electronics (SCCE) Eric Marquardt, Dave DuVal, James Simons, and Jennifer Marquardt Ball Aerospace 2017 Cryogenic Engineering Conference 7/13/2017

Scalable Configurable Cryocooler Electronics Reconfigurable and scalable design based on high heritage architecture Goal is to have a single design for different types of cryocoolers and missions Reduces NRE costs and provides a flight proven high performance CCE for lower cost Architecture used on other Ball flight instruments allowing leverage from other recent programs Hardware design based on pieces from other flight programs 80% of software has flight heritage, 20% new code is based on flight proven cryocooler control algorithms FPGA plus CPU FPGA handles all time critical functions and low level motor drives CPU adds configuration control to system allowing SCCE to support many mission types with only minor changes in software No changes to the hardware are required 2017 Cryogenic Engineering Conference 7/13/2017

Resolution: 1 mK (<46 K) Design Performance Parameter Value Bus Input Voltage 25-36 VDC Motor Power 200 W Reflected Ripple 0.4 Ap-p Cryogenic Temperature Sensors (2 ranges) Range: 4-325 K Resolution: 1 mK (<46 K) Temperature Stability ±2 mK Operating Temperature Range -35 to +50 °C Parameter Value Drive Frequency Range: 25 to 95 Hz Resolution: 1 mHz Heater Power 10 W, 2 channels On-orbit firmware Yes Launch Vibration 14.1 Grms Total Dose Radiation 100 krad Mass 11.8 kg Volume 29.5 x 24.9 x 21 cm 2017 Cryogenic Engineering Conference 7/13/2017

IRAD Control and Motor Output Board (CAMO) CAMO Board used to drive Ball Aerospace Stirling cooler and Sunpower commercial coolers New IRAD version will also be used with a Thales pulse tube Test will include active vibration control Power or Temperature control modes Constraints also include stroke limits Power limits can be applied in temperature control mode Total harmonic distortion (THD) minimization can be used in all modes on voltage, force, or acceleration 2017 Cryogenic Engineering Conference 7/13/2017

TIRS-2 Engineering Model CCE Control and motor output Two high power motor drives (compressors) and two low power motor drives (displacer or damper) Eliminates TMU position sensors 5x faster than TIRS-1 Power section is largely the TIRS-1 design Motor power supply (MPS) requirements relaxed in areas driving the design Redundant switch electronics (RSE) allows TMU motors and sensors to switch between two CCEs Improves overall system reliability 2017 Cryogenic Engineering Conference 7/13/2017

Configurable and Scalable Design is easily built to different screening standards supporting lower cost demonstration or high reliability TOR missions Minor software changes allow SCCE to drive high reliability Aerospace or two Tactical coolers Scalable input power from 25 W to 400 W or more Motor drive frequency from 25 to 95 Hz, 1 mHz resolution Fully redundant power, communications, and HDLC Self Protection Overstroke, overcurrent, high vibration, and high temperature Diagnostic mode allows telemetry waveform capture Up to 6 HLDC (0 required) 4x Power and 2x Software upload Internal launch lock 2017 Cryogenic Engineering Conference 7/13/2017

Typical Cool Down Temperature control cool down Demonstrates both power and stroke limiting 2017 Cryogenic Engineering Conference 7/13/2017

Thermal Stability Up to 6 cryogenic temperature sensors 2 ranges available TIRS-2 resolution: 30 mK < 325 K 10 mK < 120 K 1 mK < 46 K TMU rejection temperature quickly ramped 12 °C over 10 minutes Insensitive to CCE temperature ±10 mK stability maintained at cold-stage during ramp 2017 Cryogenic Engineering Conference 7/13/2017

Back EMF Control Wide range of operating conditions Frequency from 36 to 45 Hz Motor powers from 50 to 200 W Strokes from 35% to 90% TMU rejection temperature varied from +15 to +30 °C CCE rejection temperature varied from +15 to +40 °C Back EMF stroke determination is stable over long periods C1 C2 D1 % Stroke Avg Error 0.05 -0.24 0.66 % Stroke Std Dev 0.60 1.15 0.42 % Stroke Max Error 2.0 3.2 1.3 Phase (deg) Avg Error 3.40 0.55 -1.65 Phase (deg) Std Dev 1.05 1.01 1.40 Phase (deg) Max Error 5.0 2.2 3.8 2017 Cryogenic Engineering Conference 7/13/2017

4 K Stirling Precooled JT CCE Model Use two of each board Motor power supplies share current load Allows Stirling to draw most of the power but uses a heritage build-to-print design Stirling Control board is slaved using redundant communications port and is driven by the JT board Low power motors on JT used to drive the bypass valve Provides CCE with flight heritage for a 4 K cooler 2017 Cryogenic Engineering Conference 7/13/2017

TIRS-2 Current Program Status Flight boards almost finish board level testing Conformal coat this week Getting ready for CCE box level testing in early August CCE integration with TMU late-August System environmental tests start in October Cryocooler delivery scheduled for early December 2017 Cryogenic Engineering Conference 7/13/2017