1. 2010 Olin Student Projects Keith Gendreau Keith.c.gendreau@nasa.gov 301-286-6188 Fred Huegel frederick.g.huegel@nasa.gov 301-286-2285 Kurt Rush Kurt.d.rush@nasa.gov 301-286-1196 Bob Baker Robert.g.baker@nasa.gov 301.286.9882

2. 2009 Student Projects with contacts XACT Sounding Rocket Low Voltage Power Supply Point Design –Keith Gendreau, Kurt Rush, Fred Huegel, Bob Baker Modulated X-ray Source Controller –Keith Gendreau

3. Project #1, XACT Low Voltage Power Supply Point Design We are in the initial phases of designing and building a suborbital rocket payload to do astrophysics The detectors and command & data handling units need regulated low voltage power derived from “28 Volts” from Rocket battery Do a point design of a Low Voltage Power Supply (LVPS) and build a prototype –Take Electrical and mechanical requirements of LVPS –Include basic housekeeping functions –Build a command tester

4. XACT Payload and Rocket X-ray Concentrators & Star Tracker Optical Bench X-ray Polarimeters, Electronics, & MXS Overall Payload Length: 3.26 m Payload Diameter: 52 cm * Payload Mass: 80.2 kg (include ST) A 1st approximation of complete XACT rocket Black Brant VC Terrier Mk70 Aft Cone & Door Nose Cone & Recovery System Telemetry and ACS Systems

5. Very Basic XACT Block Diagram Rocket Avionics System Unregulated 28 V power Telemetry Interface XACT Main Electronics Node (XMEN) SRIB LVPS Regulated power HK PEB 1 PEB 2 HVPS Regulated power PEB 3

6. IN FLUX.. Will define, but may be a bit bigger

7. Other details We will soon specify connectors for the power output and HK address and data HK should include actual voltages and currents and some temperatures of items which may get warm Look in digikey and elsewhere for cheap, but robust converters and parts.. –Some specify shock and vibration ratings Can you make a USB based card that would allow us to query for HK?

8. Olin student Project #2: Modulated X-ray Source Controller Our new modulated X-ray source uses UV light to generate photoelectrons which are accelerated into high voltage targets to make X-rays We like to have absolute control of the X-ray flux, which is driven by absolute control of the UV light (from LEDs) Olin student project: build an X-ray source electronics box which –provides HV –Drives UV LED with arbitrary flux output –Measures currents, temperatures –Is USB controlled with PC or mac software

9. Characteristics: Rugged- no moving parts or fragile filaments- perfect for space flight. Modulates x-rays at same rate that one can modulate an LED Major NASA Uses: Timing Calibration A “flagged” in-flight Gain Calibration Source: Have calibration photons only when you want them and increase your sensitivity by reducing the background associated with the calibration photons The World’s First Fully Controllable Modulated X-ray Source

10. This has evolved to include an electron multiplier LED HV for Target (~5-10 kV) HV for Electron Multiplier (~2-3 kV

11. 1 st Magnum Multiplier MXS Multiplier HV Electron Target HV Be Window AMPTEK Detector Electron Target HV Multiplier HV

12. Output of AMPTEK Detector Pulses Modulating X-ray Output Some 1 st Data

13. Block Diagram Computer “Smarts” USB LED LED Driver HV Multiplier (DC/DC Converter) HV Target (DC/DC Converter) Source (provided by GSFC

14. Commands from computer HV target voltage (0-10 kV) –Use EMCO Q series dc/dc converter with a dac and transistor follower HV multiplier voltage (0-3 kV) –Use EMCO Q series dc/dc converter with a dac and transistor follower Arbitrary LED flux as a function of time –Asci file? Pulsed LED flux –Frequency, duty cycle or width, amplitude Query for housekeeping

15. House Keeping Items LED current (average, max) LED temperature (necessary?) HV current (or atleast current and voltage into various DC/DC converters)

16. “i-Heliograph” Can we make a low power data transmitter to send “lots” of data from the moon to the earth using a 19th century idea enhanced with 21st century technology? How does such a system compare to laser communication?

18. Replace this guy with a high speed optical modulator and an ethernet port. Replace this guy with a avalanche photodiode and an ethernet port..

19. Replacing the guy wiggling the mirror Voltage Controlled LCD displays (KHz Speeds?) Acoustic Optical Modulators (speeds up to 100 MHz)

20. Replacing the guy using his eye to see the signal on the receive end Avalanche Photo diodes

21. There should be a power savings compared to Laser Comm Lasers are ~10% efficient on producing optical output from electricity it gathers from ~25% efficient solar cells. –Total efficiency from sun = 0.25 * 0.1 = 2.5% Mirrors are ~90% reflective

22. Other factors in comparison Mass to moon –Do solar cells and power system with Laser weigh more than a mirror and heliostat? Reliability –Solar panels, motors, AOMs… –Is dust an issue?

23. 2009 Olin Job Build a Heliostat to capture the sun Pipe the light from the Heliostat through either an accoustic optical modulator or a LCD retarder Build a simple pulse frequency modulator to drive the AOM or LCD retarder Build a demodulator to read the output of an APD Predict performance and compare to Laser Comm.

24. GSFC will provide A telescope base to make a heliostat An AOM to modulate light A Circuit design to produce a FM Pulse train A Telescope for the receive end An APD (maybe dual use the one for the MCA project) The demodulator design.