N A S A G O D D A R D S P A C E F L I G H T C E N T E R 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 S y n t h e s i s & A n a l y s i s L a b o r a t o r y MAXIM Periscope Module Electrical Design Estimates C. Paul Earle 25 April 2003

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p2 Final Version 25 April 2003 MAXIM Periscope Module Design Notes & Assumptions Unregulated + 28V Supply from the S/C 1 pps timing signal + S/C time from the S/C MIL-STD-1553 Command & Data Handling Interface Requirements Provide regulated power to Sensors, Actuators, & Circuit Boards Time-Tag Sensor Data (ie. tip/tilt/piston) based on 1pps signal from S/C Implement Thermal Control & Monitoring Collect Housekeeping Data – Temperatures, Voltages, Currents Design Assumptions

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p3 Final Version 25 April 2003 MAXIM Periscope Module 1pps (1Hz) Instrument Electronics RAM 1553 I/F S/C C&DH Functional Block Diagram Figure V Survival Power Periscope (1 of 4) Actuators (4) H/K & Thermal Control Sensors: Encoders (3) Tip/tilt (2) Mechanism Drive & Control DC/DC Converter InstrumentC PU SpacecraftInstrument +28V Supply Aperture Motor (1) Heaters & Temp Sensors

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p4 Final Version 25 April 2003 MAXIM Periscope Module Instrument Architecture Power Board H/K & Therm Board BUS CPU Board (+RAM) Mech Drive Board Actuators 1pps 1553 I/F +28V (Unregulated) Address & Data Bus Regulated Power Figure 2. Position Sensors Sensor Board

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p5 Final Version 25 April 2003 MAXIM Periscope Module Sensor Readout Board Pre- Amps (8) Readout Control FPGA To RAM To/From CPU Buffer (FIFO) 13:1 MUX (digital) 8:1 MUX (Analog) A/D, MUXs, FIFO Control (1 Sensor Readout Board per Free Flyer) Figure 3. A/D (1) Linear Encoders (12) 8 Tip/Tilt Sensors (8) 12:1 MUX (digital) 12

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p6 Final Version 25 April 2003 MAXIM Periscope Module Power Board Load Calculations: CPU Board = 6 Watts H/K & Thermal Board = 4 Watts Sensor Board = 4 Watts Mech Drive Board = 4 Watts Aperture Motors = 1 Watts each (no simultaneous operation) Actuators = 1 Watts each (no simultaneous operation) Total Conditioned Power = 20 Watts Assume Converter Efficiency of ~ 70% => Power Board Dissipation = (20/0.7) – 20 = 8.6 Watts

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p7 Final Version 25 April 2003 MAXIM Periscope Module Electronics Box Power Summary Main Electronics BoxAvg. Power CPU Board6 Watts H/K & Thermal Control Board4 Watts Mechanism Drive Board4 Watts Sensor Readout Board4 Watts Power Supply Board 8.6 Watts Box Total:26.6 Watts

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p8 Final Version 25 April 2003 MAXIM Periscope Module Figure 4. Main Electronics Box Summary CPU Board (6W) Total: ~ 26.6 Watts (avg.) Power Board (8.6W) H/K & Thermal (4W) 7 in (17.5 cm) 10 in (25 cm) 8 in (20 cm) 6 in (15 cm) Estimated Mass ~ 7 Kg Estimated Power ~ 26.6 Watts (Avg.) Estimated Size ~ (25 x 15 x 17.5) cm. Main Electronics Box Sensor Board (4W) 6 in (15 cm) Mech Drive Board (4W)

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p9 Final Version 25 April 2003 MAXIM Periscope Module Instrument Power Summary Spacecraft Power Bus Requirement End ItemsAvg. Power 1 Main Electronics Box 26.6 Watts 1 Watt each 1 Watts Drive 1 Watt each 1 Watt Heaters 25 Watts Instrument Total: 53.6 Watts

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p10 Final Version 25 April 2003 MAXIM Periscope Module Main Electronics Box ~ $4.3M (Includes Design, Parts, Fabrication, Test, & ETU) Cost Estimate

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p11 Final Version 25 April 2003 MAXIM Periscope Module Low risk design. Essentially design re-use for each of the circuit boards. No science data on the Free-Flyers and the Hub spacecraft. All Sensor Data and Housekeeping Data is passed to the spacecraft via the 1553 bus. Design could possibly be further optimized by moving CPU functions to the spacecraft side of the bus and utilize the FPGA for the instrument control functions. Packaging could possibly be reduced by combining the actuator drive board with the sensor readout board at the expense of drive circuitry redundancy. Example: A single drive circuit (with one backup) could be multiplexed to each of the actuators given non- simultaneous operation. Conclusion

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p12 Final Version 25 April 2003 MAXIM Periscope Module Backup Slides (Electrical Design Estimates)

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p13 Final Version 25 April 2003 MAXIM Periscope Module Processor Board CPU (RAD 6000) Startup ROM EEPROM Memory (Thermal control logic) Ethernet I/F 1553 I/F RAM Time Stamp Function S/C 1pps S/W Dev. Figure 5.

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p14 Final Version 25 April 2003 MAXIM Periscope Module Drive Cmd From Processor Driver Amp I+I motor Open/close detection HK Mux + - To H/K Board Actuator Current Actuator Voltage Figure 6. Mechanism Drive Circuit Aperture door

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p15 Final Version 25 April 2003 MAXIM Periscope Module Thermal Control circuit Figure 7. DAC HK Mux V Ref I Source I+I+ I+I+ V+V+ Heater Current Heater Voltage T sensor Voltage T sensor Current + - From Processor To Central HK Heater T sensor (1 of n circuits shown) From Processor

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y Electrical Design Estimates, p16 Final Version 25 April 2003 MAXIM Periscope Module Mux 16-ch AD A/D Conv. AD 1672 To Controller Board Power Temp... H/K FIFO V Ref I Source T sensor Voltage T sensor Current Mux V+V+ V-V- HouseKeeping Circuits (1 of n temp sensors) Figure 8. I+I+