MAVEN Risk Reduction Phase Task Status STATIC Instrument Prototype Development David Curtis

1. Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission MAVEN Risk Reduction Phase Task Status STATIC Instrument Prototype Development David Curtis Particles and Fields Package Manager

2. Planned Work • STATIC is an Ion Mass Spectrometer, based on heritage designs but in a new configuration • The CSR stated we would do the following development on the STATIC instrument prototype in Phase RR: The partial STATIC demonstration unit built in Phase A (see Section F.5.d.3.2) is expanded during the RRP to include the electrostatic analyzer, the analyzer sweep high voltage supply, and the instrument control logic (FPGA). This nearly completes the STATIC ETU (all except the MCP, HVPS, and LVPS, which are essentially standard designs), and enables a more complete end-to-end demonstration of the instrument, reducing risk entering Phase B. Phase A Prototype STATIC

3. Analyzer Sweep HVPS • Requirements: • 3 voltages to control the STATIC Electrostatic Analyzer • Programmable over -2V to +4kV with 0.01V resolution/noise (400,000x dynamic range) • Capable of a few Hz sweep rate over the full dynamic range (nominally a log sweep) • A number of ways to achieve these requirements were investigated on paper • MAVEN_PF_STATIC_010 • Built a breadboard to check out a few possible designs • Zero Drift opamps and Monitoring circuits

4. Breadboard Sweep HVPS • Two candidate ‘Zero Drift’ opamps easily meet the 10mV requirement • Offset monitoring circuits also demonstrated to work Resolution Requirement

5. Prototype Sweep HVPS • A prototype of the full sweep supply was designed, layed out and built • Form fit and function of the flight supply • So far only two of three outputs populated • Includes both Zero Drift opamps and Offset Monitoring • Testing demonstrates supply meets requirements

6. Digital Board • The digital board includes: • Interface to the PFDPU, instrument front end (TDC), HVPS • TDC event handling, coincidence logic, TDC to mass conversion, event binning and formatting • HVPS arming, fixed HV control, Sweep HVPS waveform generation • Test pulser control • Housekeeping collection and formatting • Functionality implemented mostly in an Actel RTAX FPGA • Requirements documented: MAVEN_PF_STATIC_011 • Specification generated: MAVEN_PF_STATIC_012 • Digital board designed and layed out • FPGA designed and programmed • GSE developed to simulate the PFDPU, provide control and data display • Board and programmed Actel functional tests completed

7. Digital Board Prototype, Integration Digital Board Prototype Prototype Electronics Integration

8. Analyzer work • Analyzer work was re-prioritized • Fabrication of prototype ESA was deemed less important than other analyzer work • Will continue to work with spare Wind project ESA for now • The following designs were developed (on paper): • Mechanical Attenuator • Provides better dynamic range overlap with NGIMS • The ESA deflectors • The ESA and aperture housing and grids • The ESA Electrostatic attenuator • Minor modifications to the MCP-TOF HV design based on results from Phase A prototype testing • The following was built for the analyzer prototype • Modified TOF/MCP HV connectors • New MCP mounting hardware • New MCP grids • New carbon foil mounts (improved design)

9. System Integration, Future Work • Digital Board, Sweep HVPS, and TDC have been integrated and tested • Testing continues • No significant issues found so far • Integration with 14kV supply and Analyzer pending • Calibration Chamber testing to follow later this year to perform end-to-end tests, verify performance • Intermediate pressure tests to be completed to determine • Maximum safe operating pressure for STATIC high voltage • Any indications that might be provided by the instrument prior to breakdown as pressure rises • These tests will help determine if and how we need to protect STATIC from breakdown during deep dips • ESA prototype to be fabricated early next year