1 PFP IPDR 2010/6/ Particles and Fields Package (PFP) Instrument Preliminary Design Review System Engineering David Curtis, PF Package Manager

2 PFP IPDR 2010/6/ The PF Package Solar Wind Ion Analyzer (SWIA) – SSL Solar Wind Electron Analyzer (SWEA) – CESR / SSL Langmuir Probe and Waves (LPW) – LASP / SSL LPW/Extreme Ultra-Violet (LPW-EUV) – LASP Solar Energetic Particle Detector (SEP) – SSL Magnetometer (MAG) – GSFC Supra-Thermal and Thermal Ion Composition (STATIC) - SSL MAG (2) LPW (2) SWIA LPW-EUVM SEP (2) SWEA STATIC

3 PFP IPDR 2010/6/ PFP Block Diagram 10cm

4 PFP IPDR 2010/6/ PFP Instruments (1) SWEA STATIC SWIA

5 PFP IPDR 2010/6/ PFP Instruments (2) PFDPU MAG EUV SEP

6 PFP IPDR 2010/6/ PFP Instruments (3) - LPW Booms Pre-deploy Post- deploy

7 PFP IPDR 2010/6/ PFP Harnessing

8 PFP IPDR 2010/6/ Requirements Flowdown Requirements through Level 3 are Project-controlled and maintained and linked via DOORS database –PFP team works with Project to maintain flowdown and validate that requirements are adequate to ensure mission objectives PFP Provides Inputs to Level 1,2,3 requirements that flow up from instrument requirements –Magnetics, Electrostatics, EMC, Pointing, Operations PFP Interacts with LM on Spacecraft-to-PFP ICD –Electrical, Mechanical, Thermal, FOV interfaces –Mass, Power, Telemetry Resources –Fault Management PFP Team controls Level 4 and below using PFP Configuration Management System –Requirements linked to upper level requirements –Level 4 provided to Project for review

9 PFP IPDR 2010/6/ Top Level Requirements Performance Requirements Document –MAVEN-PM-RQMT-0005, Mission Requirements (Level 2) –MAVEN-PFIS-RQMT-0016, PFP Requirements (Level 3) –PFP Instrument Specifications, Software Requirements (Level 4) Mission Assurance Requirements –MAVEN-PM-RQMT-0006, Mission Assurance Requirements –MAVEN_PF_QA_002, PFP Mission Assurance Implementation Plan Software –MAVEN-SYS-PLAN-0020, MAVEN Software Management Plan –MAVEN_PF_SYS_008, PFP Software Development Plan –MAVEN_PF_FSW_002, PFP Software Requirements Spec Mission Operations –MAVEN-MOPS-RQMT-0027, Mission Operations Requirements Environmental Requirements Document –MAVEN-SYS-RQMT-0010 Spacecraft to PFP ICD –MAVEN-SC-ICD-0007

10 PFP IPDR 2010/6/ PFP L4 Requirements MAVEN_PF_SYS_010 – Flight Software Requirements (L4) MAVEN_PF_FSW_002 – Software Requirements Specification (L5) MAVEN_PF_SYS_003 – Power Converter Requirements MAVEN_PF_PFDPU_001 – Data Controller Board Specification MAVEN_PF_LPW_001 – LPW Specification (L4) MAVEN_PF_SEP_001 – SEP Specification (L4) MAVEN_PF_STATIC_001 – STATIC Specification (L4) MAVEN_PF_SWEA_002 – SWEA Specification (L4) MAVEN_PF_SWIA_001 – SWIA Specification (L4) MAVEN-RQMT MAVEN Magnetometer Specification (L4) Various – FPGA Specifications (Level 5)

11 PFP IPDR 2010/6/ PFP ICDs MAVEN-SC-ICD Spacecraft to PFP ICD MAVEN_PF_SYS_004 – PFDPU to Instruments ICD MAVEN_PF_SWEA_001 – SWEA CESR to SSL ICD MAVEN_PFDPU-002 – PFDPU Board Outlines MAVEN_PF_SYS_013 – Harnessing Drawing MAVEN_PF_SYS_016 – Connector Pinouts MAVEN_PF_PFDPU_002 – PFDPU PC104 Connector Pinouts Various – Mechanical ICD Drawings (Inputs to PFP to Spacecraft ICD)

12 PFP IPDR 2010/6/ Radiation Environment MAVEN project has provided radiation analysis –MAVEN Mission ERD Describes Radiation Environment 13krads(Si) behind 100mils Al Protons, SEE environments –MAVEN_SYS_HDBK_0004 Radiation Environment Description & Component Test Guidelines Goes into more details Indicates component qualification requirements PFP EEE parts will meet radiation requirements –By manufacturer’s spec, technology, or test –Verified by Parts Control Board review

13 PFP IPDR 2010/6/ Contamination Control PFP includes some contamination sensitive instruments –SWEA, SWIA, STATIC containing Microchannel Plates which are sensitive to dust, hydrocarbons, water, contaminants –SEP contains Solid State Detectors sensitive to contaminants –EUV contains optics sensitive to dust, contaminants –Various instrument surfaces (radiators, etc) are sensitive to contamination –PFP Contamination Control Plans dictate controls Other instruments and spacecraft subsystems also dictate contamination control measures to prevent cross-contamination –Planetary Protection also impacts cleanliness requirements –Spacecraft Contamination Control Plan dictates controls at ATLO –Project level contamination control plan pending Sensitive instruments have doors to seal sensitive detectors and near-continuous purge requirements Standard Materials control (TML) limits molecular cross- contamination –Vacuum Bakeout demonstates cleanliness Clean room practices, bagging, inspections, cleaning as needed maintains instrument cleanliness through I&T, ATLO

14 PFP IPDR 2010/6/ EMC, Magnetics PFP includes instruments sensitive to Electrostatics, Electromagnetics, and Magnetics –Magnetometer measurements require a magnetically clean environment, DC to 16Hz 2nT DC, 0.25nT AC at Magnetometer –LPW and particle instruments require an electrostatically clean spacecraft Exterior surfaces conductive (with analyzed exceptions) Exterior surface grounded (with analyzed exceptions) –LPW requires a quiet low frequency EME environment 0.02Hz-10Hz, by analysis 100KHz-2MHz ~GEVs levels, by test Spacecraft, Electra, and other instruments also dictate EME requirements All requirements captured in the MAVEN ERD –Verification by standard EMC tests, Magnetics Screening, Analysis EME Working Group tracks compliance with surveys, watch lists, early measurements, analyses, etc. –PFP team participates in EME WG

15 PFP IPDR 2010/6/ Verification & Validation MAVEN_PF_SYS_023 PFP Verification & Validation Plan (and Environmental Test Plan) –preliminary version delivered to Project MAVEN_PF_SYS_022 I&T Plan –preliminary version delivered to Project All PFP requirements to be verified –Test, analysis, inspection, or demonstration –Test is the preferred method of verification –Requirements are verified as early as possible at a low level Verifies subsystems, Retires risk –Requirements are verified at the highest level of assembly possible Often involves verifying a requirement at several levels –System Engineer tracks Verification against IRD Reports on status at PER, PSR –PFP Level 3 requirements indicates briefly the planned method of verification (e.g. Thermal Vac) –V&V Plan outlines the tests and constraints –I&T Plan outlines order of testing, logistics (more in I&T presentation) –Selected performance related parameters to be trended through I&T & ATLO Validation by Instrument Scientists (end users) –Completeness of requirements –Hands-on involvement with calibrations, system level tests

16 PFP IPDR 2010/6/ Interface Verification PFDPU Interface Simulators used for instrument-level testing –Provided by SSL –Capable of testing off-nominal cases Integrated EM PFP testing checks full package Spacecraft Simulator used for PFDPU testing –Provided by SSL –Capable of testing off-nominal cases EM PFDPU to EM Spacecraft interface test checks interface hardware –Around CDR FM PFP to spacecraft power system test early in FM I&T to verify power characteristics –In-rush, current limiters, etc.

17 PFP IPDR 2010/6/ Integration and Test Flow

18 PFP IPDR 2010/6/ Environmental Test Flow

19 PFP IPDR 2010/6/ Qualification Approach Engineering Model (EM) of the PFP shall be used to demonstrate that the design meets the functional requirements –And to reduce risk of excessive ‘fixes’ to FM –Selected environmental tests, such as STATIC accoustic tests, shall be used to retire risk, but typically not as qualification tests Flight Models (FM) shall be tested to Protoflight Levels –Possible exceptions only when EM can be shown to be sufficiently similar to FM at PER to show that Acceptance levels are adequate for FM – not currently baselined. –Qualification levels called out in ERD

20 PFP IPDR 2010/6/ Environmental Verification Matrix

21 PFP IPDR 2010/6/ Mechanical Systems Paul Turin, Mechanical Lead

22 PFP IPDR 2010/6/ Peer Reviews System-level RFAs from the Mechanical Peer Review –Actions are White, Recommendations are grey

23 PFP IPDR 2010/6/ Instrument Limit Loads Problem: Loads derived from MAC curve and prelim random vibe spec exceed the loads heritage instruments were designed for. Solution: We will wait for the 1 st CLA results (~October ‘10) which are expected to lower the limit loads If the loads are still high we will modify the designs as needed at that point.

24 PFP IPDR 2010/6/ Mechanical Verification Instrument designed to Environmental Specification Requirements (by analysis): –Limit Loads, Stiffness, Venting Instrument tested per Environmental Spec: –Mass Properties at component level Mass, CG MOI by analysis –Sine, Random vibration at component level FM to PF levels Structural Loads testing by Sine Burst or Centrifuge if sufficient margins cannot be demonstrated by analysis –Acoustic test at the component level planned only for STATIC Thin foils potential acoustic concern First tests at EM level All remaining systems will see acoustics testingat the Observatory level –Self-shock to be verified for deployables (2 times) System shock to be tested at Observatory level

25 PFP IPDR 2010/6/ Thermal Verification PFP Thermal design verified by analysis and Thermal Vacuum testing –Analysis to include launch transients, aeroheating, thruster heating –Modeling and Analysis performed cooperatively between PFP and LM Models provided to LM, waiting on environments (deck temps, etc) Model results will likely impact operational heater requirements –Models to be verified by Thermal Balance tests At observatory level unless component level tests dictated by design heritage, thermal margins, and sensitivity to modeling assumptions (TBR) –Component-Level Thermal Vac cycling tests described in I&T section

26 PFP IPDR 2010/6/ Return to Curtis

27 PFP IPDR 2010/6/ EMC Verification Instrument conforms to Design Guidelines and Requirements ERD: –Magnetics Identified magnetic materials and circuits are provided to EME Working Group, which maintains a watch list; participate in analysis and suggestions for mitigations as required SEP contains permanent magnets in a self-cancelling configuration –THEMIS test results indicate matching is effective Magnetics will be verified by magnetics screening at the component level (EM and FM) and observatory-level tests –ESC Exterior surfaces are conductive and connected to chassis ground ESC Verification at the component level –surface resistance measurements –EMC: Frequencies list maintained by EME Working Group Supplies, interfaces have filtering, soft start –PFDPU supplies synchronized to limit conducted noise, beats to LPW, MAG Verification by Package-level EMC tests: –ETU (CE) –FM (CE, CS, RE, RS, BI, On/Off transients) –Spacecraft compatibility tests

28 PFP IPDR 2010/6/ Grounding Primary (spacecraft) return isolated from secondary return (per ERD, >1Mohm) –Common operational power converter isolates all instrument returns from spacecraft primary return Spacecraft interfaces all differential Secondary return connected to chassis ground in each component –SWEA, SWIA, STATIC instruments have internal converters providing ground isolation to avoid chassis ground loop to PFDPU –MAG sensor has no chassis; thermal blankets grounded to harness braid –SEP sensors connected to chassis ground via harness to avoid ground loop (no local converter) Approved deviation –LPW preamps on floating ground (no connection to spacecraft chassis. –Single-ended instrument interfaces configured to minimize AC chassis currents Approved deviation PFP Grounding Diagram MAVEN-PF-SYS-014

29 PFP IPDR 2010/6/ Grounding Diagram

30 PFP IPDR 2010/6/ Gold Rule Compliance MAVEN_PF_SYS_006 PFP Gold Rules Compliance Matrix submitted to Project –Project to submit waivers as needed (with PFP support) after PDR Potential Issues: –2.01, 1000 hours testing. Possible issue with redundant hardware; we target 1000 hours total, not per side –2.07, System Level Deployments. LPW booms cannot be deployed safely at the system level due to difficulties providing G-negation. –2.18, Redundancy. In some cases PFP has routed redundant signals through a singe connector.

31 PFP IPDR 2010/6/ Limited Life Items MAVEN_PF_QA_008 Limited Life Items List submitted to Project PFP has no items which do not exceed a factor of 2 beyond expected mission life

32 PFP IPDR 2010/6/ Limited Life Qualification Mechanisms shall be qualified by life test of the prototype, plus ground test of the flight system

33 PFP IPDR 2010/6/ Fault Management MAVEN_PF_SYS_020 Fault Management Description Document –Describes PFP Faults and how they are managed –Faults managed by PFP Hardware Goes into hardware specifications –Faults managed by PFP software Goes into Flight Software Requirements –Faults managed by the Spacecraft Goes into ICD –Faults Managed by the Ground System (MSA/SOC) Goes into Flight Rules

34 PFP IPDR 2010/6/ PFP Faults Sun in SEP FOV –Protected by closing Attenuator –Ground (sequence) & Spacecraft (attitude) rules EUV RAM ions –Protected by closing shutter –Ground (sequence) & Spacecraft (Accelerometer) rules High Voltage at High Pressure (Deep Dip) –Protected by high voltage shut-down –Ground (sequence) & Spacecraft (Accelerometer) rules Overcurrent –PFP instrument circuit breakers, –Spacecraft overcurrent protection PFP processor upsets –Recovered by processor reset –PFP watchdog, spacecraft (communication) protection Spacecraft safeing –PFDPU Safes instruments on loss of spacecarft communications –Hardware closes EUV shutter, SEP attenuators on Instrument power- down

35 PFP IPDR 2010/6/ Trade Studies Open at SRA Second STATIC Trade Study Completed –Insufficient resources to support Second STATIC –Imposes Additional reliability requirements on STATIC LPW Lyman Alpha Measurement Trade Completed –Additional photodiode added to EUV APP Pointing Optimization for Side Orbits –Plan to share side orbits between STATIC and IUVS agreed to Deep Dip Pressure Sensitivity for HV Instruments –LM analysis indicates they can provide HV safeing based on accelerometer measurements (with margin) to potentially allow deeper operation of HV instruments –Tests on EM instrument pending to see if safeing threshold can be increased Thruster Plume Analysis Completed –SWEA analyzer location adjusted to avoid thruster heating –All other instruments see minimal thruster plumes and can operate during thruster firing

36 PFP IPDR 2010/6/ Trades Completed Since SRA LPW boom length was increased from 6m to 7m –CCR84, 142 –Closer to RBSP heritage design –Additional margin to wake/shadow concerns SWIA and STATIC instrument attenuators added –CCR 90,91 –Improved measurement dynamic range to better cover full range of expected fluxes SWIA preamps and MCP changed to support higher rates –CCR 92, 150 LPW ‘sounding’ mode added to provide plasma wave electron density measurements –CCR 163

37 PFP IPDR 2010/6/ Outstanding Trades / Issues Magnetics –Original sensor location on solar array does not work Too close to solar array strings AC magnetics too high –Working with Project & LM on alternatives SWEA, SWIA, STATIC Aperture Surface Treatment –Needs to be black to avoid overheating (esp. SWEA) –Candidate treatments pending Atomic Oxygen test Amptek HV801 –MMS lot failed qualification –Used in SWIA, STATIC –Considering options High Structural Loads Levels –Waiting on CLA in ~September –May need some redesign if loads remain high Operational Heater Requirements –Pending thermal modeling feedback from LM LPW Sensor Options –Considering changing LPW sensor to a sphere based on recent changes to spacecraft operational modes –Considering changing from a caged to a fixed sensor

38 PFP IPDR 2010/6/ PFP Mass MAVEN_PF_SYS_002 CCR182 submitted to reallocated margins amongst subsystems as shown –so that no subsystem is below 20% Contingency

39 PFP IPDR 2010/6/ Mass Tracking Chart

40 PFP IPDR 2010/6/ PFP Power MAVEN_PF_SYS_002 CCR182 submitted to reallocated margins amongst subsystems as shown –so that no subsystem is below 15% Contingency –Also to fix low heater peak power margin Liens: –Expect to need operational heat during eclipse None allocated for most instruments; amount needed pending thermal analysis Preliminary estimates included for MAG and EUV heaters

41 PFP IPDR 2010/6/ PFP Power Trend

42 PFP IPDR 2010/6/ PFP Data Rate Per allocations from PI

43 PFP IPDR 2010/6/ BACKUP Slides

44 PFP IPDR 2010/6/ Design Loads - MAC The Design Load is the Limit Load x appropriate Safety Factor. Design loads calculated from Mac Limit Loads:

45 PFP IPDR 2010/6/ Design Loads - Random The Design Load is the Random quasi-static equivalent (grms) x Peak Response Factor (s) x appropriate Safety Factor. Design loads calculated from Random specs: Worst case of MAC- and Random-derived Design Loads: