SCM PREAMP & SENSOR Fabrication Readiness Review P. Leroy

LPP Team Co-IO. Le Contel, A. Roux Technical ManagerP. Leroy Lead EngineerC. Coillot Assistant EngineerD. Alison QA EngineerL. Meslier (BTS Industrie) => 0.5 FTE LPP/CNRS-Ecole Polytechnique PALAISEAU, FRANCE SCM Team

Block Diagram

+X-X -Y +Y RF xnpdr PSEES Battery C&DH Star Sensors Mag boom (stowed) DPU Mag boom (stowed) S-Band Antenna FEEPS SCM Pre-Amp Navigator USO DSS SPACECRAFT DECK COMPONENTS S/C Location (1)

CEBEDI SDP ADP AFG DFG SCM AEB INSTRUMENT DECK COMPONENTS (BOOMS DEPLOYED) S/C Location (2)

SCM PREAMP

Low Noise Preamplifier 46dB Amplification & Filtering 31.5dB Feedback B CAL V out V in From DSP Scope: Design Overview Sensor (3 one axis sensors in a triaxial structure) – Primary coil – Secondary coil (feedback) Preamplifier (3 analog channels, Power Supply Regulation + Calibration Buffer) – 1st level of amplification: Low Noise + Feedback – 2nd level of amplification +filtering – Calibration in flight from DSP 33mm 30mm 18mm MMS Preamp packaging

Action items since last review (CDR) Gains have been adjusted to meet the resolution requirement The preamp has been tuned with the EM4 sensors (4 mm ferrite cores). The sensitivity requirements are also satisfied now Radiation Qualification of the commercial JFET finished, LAT also. Screening end 16 OCT 2010

Screws (Stainless Steel) Cover (Al 2024 T851) Box (Al 7075 T7351) SCM Sensor harness routed through the Spacecraft Deck Connectors: – 15 pins DSub HD PCB mount (hard- mounted before soldering) – 26 pins DSub HD crimp connector Surface treatments: – Alodine 1200 – Black Anodization Right Angle Vent Hole Ø 2mm FIELDS Preamp to Spacecraft Mechanical/Thermal ICD ( ) Preamplifier Housing 3D+ Hybrid Module 4 spacers added in the corners of the 3D+ Hybrid (Epoxy+EC2216) for vibration hardness Ground lug connection Hole for Wire Thread Insert #8-32 x 1.5d

Fixtures MICD C Preamp interface: 4x Ø3.99 mm with the following pattern Fasteners provided by the S/C team

3D+ Hybrid Workflow

Preamp Manufacturing Workflow

Parts status and 3D Module Manufacturing Flow Revision 3 of the Detail Specification Document from 3D+ (3DPA2800) released and signed All parts are in PIMS Radiation memo written on the influence of total dose degradation and single event transients on the RH1013 OP AMP JFET Radiation test report released by LPP sub-contractor (qualification successful) 3 DPA done on all part references Screening on the commercial parts (done prior to QM fabrication): – done on the 2 capacitors AVX LD103C225KAB and AVX LD10YC475KAB – JFET 404 (done on LOT2 for the QM flow, we have another lot, LOT1, in house, having passed LAT and Radiation Testing) All other components are compliant with the ESA ESCC standard. No additional screening planned. 2 component kits for the QM manufacturing – 1 QM deliverable – 1 backup kit 9 component kits for the FM manufacturing – 4 FM + 2 SM + 2 LAT deliverable – 1 backup kit Two lots of OP AMP RH1013, Lot 1: 67 parts, Lot 2: 20 parts (need 7 by 3D module).

JFET LS U404 Screening Issue Status after the screening of 40 parts: – 1 part rejected after mechanical inspection – 4 parts rejected after C-SAM inspection (Scanning Acoustic Microscopy) – 13/14 datasheet criteria met after Burn-In (160h/125°C) except CMR (Common Mode Rejection) Datasheet requirement is -95 dB or below for CMR 3 parts OK, CMR < -95 dB (between -112 dB and -95.1dB) 32 parts rejected, CMR > -95 dB (between dB and -83 dB) All parts have drifted CMR not measured during LAT and Radiation Testing – Gain, Noise, Power Consumption and Polarization are the relevant parameters for our design, all were nominal and tested in SCM design configuration after LAT and Radiation Testing – CMR could have an influence on the Power Supply Rejection Ratio (not sure) – No functional risk expected. Only risk = PSRR degradation (if any)

PREAMP Stage 1 Common Mode Rejection is not driving the design B

Proposed Action Plan

Schedule

SCM SENSOR

Sensor Materials, Assembly Sequence and Processes Raw Cores Characterization (LPP) => 1 Report File follows each sensor during the manufacturing flow (electrical tests, mass measurements, thermal cycling…) Ferrite Cylinder (length=20cm)Ferrite 3C95Ferroxcube Machining (PRECINET) Cores Characterization (LPP) Winding (TECHNOPOINT) Wire, 63μm (primary winding)Grade 1(TECHNOPOINT) Wire, 140μm (secondary winding)Grade H(TECHNOPOINT) Kapton Tape(UNH) Lacing Tape(TECHNOPOINT) Copper Foil 30μm (electrostatic shielding) Shielded Triplet Splicing and Soldering (TECHNOPOINT) Shielded TripletF A HG-B2 ( B2)Draka Fileca Heat Shrinkable SheathRNF100 RAYCHEM(TECHNOPOINT)

Sensor Materials, Assembly Sequence and Processes Insertion in a PEEK Tube, Electrostatic Shielding Soldering (TECHNOPOINT) PEEK Tube450GL30PMDK GlueC2216 Windings Characterization (TECHNOPOINT+LPP) X Ray Inspection (ANTICYP) Potting (LPP) ResinMapsil 213-BMAP Silicones Windings Characterization (TECHNOPOINT+LPP) Mounting of the sensors in the structure Triaxial structurePEEK 450CA30STAE PEEK Tube Closed Coil insertion in PEEK tube

SCM will be located at 4 m from the S/C and 1 m from AFG Pigtail connector mounting on a bulkhead on the boom Temperature measurement provided by a thermistor Doc. James Sturm GSFC Doc. BTS Industrie, D ed00 SCM Adapter => Mag Boom ICD

Positioning before fastening + sliding at the interface => 4 countersunk screws, in titanium TA6V (change since CDR: no more PEEK fasteners considered) FIELDS SCM to Spacecraft Mechanical/Thermal ICD ( B), 3D update needed, slight modifications due to the use of PEEK 450CA30 SCM Triaxial structure fastening

Changes since CDR Thermal Cycling on EM3 Sensor and X-Ray inspection reveal a weakness in the design Bepi Colombo sensors tested safely up to 200°C (and down to - 180°C in June 2010) Ferrite core diameter smaller on MMS (3mm) than on Bepi Colombo (4mm) => Evolution for the QM, validated on EM4 – Increase in diameter of the ferrite core to strengthen the sensors (less risk during manufacturing) – Negligible added mass, same overall dimensions Material of the structure changed due to a problem of maturity revealed during procurement of bars and blocks – PEEK 90HMF20 => PEEK 450CA30 – Structure drawings updated Slight crack, very thin after the first thermal cycling of EM3 Clearer after vibration at acceptance levels

Coils Manufacturing Workflow

Triaxial Sensor Manufacturing Workflow

Harness Parts Composite Braided Shield SGlenair Shielded TripletF A HG-B B2 Draka-Fileca Twisted Shielded PairF A HG-B B2 Draka-Fileca Connector Back-Shell + Adjustment Platen on the pigtail DW Sommer SubD HD Connector 15P B DEMA 15P NMB FOC&K SubD HD Connector 15S B DEMA 15S NMB FOC&K SubD HD Male Contacts BC&K SubD HD Female Contacts BC&K

SCM Connector Bracket

Harness Manufacturing Workflow

Schedule

QA Activites, Qualification, Calibration

QA Activities Status Done – Configuration under control (Excel Configuration File) – SCM dedicated project documentation (all forms) – Manufacturers & suppliers defined – Manufacturing flowchart with all KIP/MIP (Mandatory/Key Inspection Points) To be done – AIT documented (logbook filling…) QM/FM fully under configuration: – 100% of our Items are identified by a drawing or a product ref. – Etching will be done at strategic locations on the main parts – Specific quantity is forecast for each model – Item Batch will be recorded in the configuration if any. – Materials & surface treatments controlled – Certificates of conformance will be provided – NCR, ECR, RFW/D will be followed in terms of each item FM will be built as QM (including QM NCR preventive & corrective actions)

SCM Configuration File

AIT Logbook

Env Testing & Qual Workflow

Resources Special OperationsLPPLPP AlternateSubcontractor SCM Electrical Subsystems Preamplifier 3D Hybrid Fabrication 3D+ PWB Fabrication, PWB Populating (3D Hybrid, Connectors), Integration in Housing STEEL Electronique Sensor Windings Technopoint Electrostatic Shielding Soldering and Integration in PEEK Tubes DAL, PLECCOTechnopoint Pigtail Connexion DAL, LMEYSIIAS Harness IAS Preamplifier + Sensor GSE DALYSI Overall Calibration PLECCO SCM Mechanical Subsystems Preamplifier Housing Preamplifier Housing Manufacturing BTS Industrie Sensor Ferrite Cores Machining Optik-C PEEK Tubes Machining MPC Triaxial Structure Machining STAE PEEK Fasteners Machining BTS Industrie Potting, Triaxis Assembly PLECCO LPP SCM Regular TEAM PLE = Paul Leroy (Research Engineer, permanent position) DAL = Dominique Alison (Assistant Engineer, permanent position) LME = Lionel Meslier (QA Engineer, BTS Industrie, 0,5 FTE) LPP Alternate Sources CCO = Christophe Coillot (Research Engineer, permanent position) YSI = Yannick Simon (Study Engineer, temporary position Sep 2010-Dec 2011)

SCM PREAMP & SENSOR Fabrication Readiness Review P. Leroy