THEMIS Instrument PDR 1 UCB, April 19-20, 2004 Spin Plane and Axial Boom Preamps & Sensor Cable...

THEMIS Instrument PDR 1 UCB, April 19-20, 2004

Spin Plane and Axial Boom Preamps

&

Sensor Cable Fabrication

Critical Design Review

Daniel Schickele

University of California - Berkeley


• Ease of disassembly to facilitate replacement of parts.

• Tantalum radiation shielding for OP-15 Can.• Minimal difference of parts for Spin Boom and Axial

boom configurations.• Angled forward surfaces (Top) to reduce

photoelectron flux to wire.• Angled rear surface (Guard) to reduce probability

of hang up upon deployment.• Electrical isolation of bias surfaces.• Minimum input capacitance between sensor input

and preamp structure.• Thermal Predicts: -120ºC to +60ºC

Mechanical Requirements & Specs


Physical Characteristics

All external parts to be gold plated and DAG 213 coated.• Top• Screw Fitting• Guard• Cable Holder


Spin Plane & Axial Boom Preamps


Exploded SPB Preamp


Spin Plane & Axial Boom Preamps


PC Board Subassembly


Preamp Discussion

Outline of changes since PDR

• Replaced Fuzz Button with Ferrule Spring and Spring PlateImproved reliability of electrical contact to sensorFacilitated trace routing on PC Board

• Modified tantalum Front ShieldImproved reliability of electrical contact to sensorFacilitated trace routing on PC Board

• Changed to Mill-Max receptacles and pinsProblems swaging Keystone pins to NASA requirements


Preamp Issues & Concerns

• THE SPECIFIC SITE CONCERNS ARE BASED ON OUR PRELIMINARY THERMAL ANALYSIS. A MORE EXTENSIVE THERMAL ANALYSIS IS UNDERWAY AND SHOULD BE COMPLETED IN THE NEXT TWO WEEKS.

• GENERAL INSPECTION NOTESAll items should be inspected both pre and post test.All places where dissimilar materials are joined.All bonded surfaces visually accessible.

• PC BOARD ASSEMBLY Inspect Ferrule Spring for fatigue or damage.Inspect Spring Plate for deformation and it’s solder joint.All surface mount components especially their soldered joints.Pin swaged joint.OP-15 soldered leads.Front Shield contact with PC Board.

• PREAMPSPrimary areas of concern are large diameter plastic parts:* The Bottom (which has been addressed by splitting the ring).* The Sphere Mount particularly the site of the 0-80 Flat Head Screws.* The Socket Holder fit in the guard, the Mill-Max Receptacles for loosening, and the fit of the Can

Shield in the Socket Holder.Bonding between Guard, Peek Stub, and Cable Holder. AXB PREAMP SPECIFIC - Threaded joint between Sphere holder with its threaded insert and the

Sensor Tip Piece.SPB PREAMP SPECIFIC - Fine Wire Crimp.

• Mill-Max Receptacles & PinsFlight Approval Pending. (UCB QA/GSFC QA)


Preamp Supporting Slide 1

Dia Len CTE Min T Delta Dia Delta Len

ITEM NO. QTY. PART NO DRAWING NO REV WEIGHT MATERIAL (in) (in) (in/in deg C) (deg C) CTE*Trange (in) (in)

1 1 bottom THM-PRE-MEC-108 A 0.361 PEEK 450G 0.8310 0.2510 4.70E-05 -120 -0.0066 -0.0055 -0.0017

2 1 screw fitting THM-PRE-MEC-109 3 6.505 BRONZE, 544 PER ASTM-B139-95 0.9110 0.5050 1.80E-05 -120 -0.0025 -0.0023 -0.0013

3 1 guard THM-PRE-MEC-107 3 1.900 AL ALLOY 6061-T6 PER QQ-A-200/8 0.7720 0.9890 2.34E-05 -120 -0.0033 -0.0025 -0.0032

4 1 top, axb THM-AXB-MEC-801 1 4.814 AL ALLOY 6061-T6 PER QQ-A-200/8 0.9110 0.5790 2.34E-05 -120 -0.0033 -0.0030 -0.0019

5 1 spring washer THM-PRE-MEC-110 2 0.120 BERYLLIUM COPPER 0.7760 0.0200 1.75E-05 -120 -0.0024 -0.0019 0.0000

6 4 CR-FHM1 0.06-80x0.125x0.125-N 0.041 ST STL 0.1380 0.1250 1.73E-05 -120 -0.0024 -0.0003 -0.0003

7 1 sphere mount, axb THM-AXB-MEC-802 1 0.717 PEEK 450G 0.7000 0.2740 4.70E-05 -120 -0.0066 -0.0046 -0.0018

8 1 threaded insert, spirol SPIROL # 36945 1 0.430 BRASS 0.1200 0.2140 2.05E-05 -120 -0.0029 -0.0003 -0.0006

9 1 pc board assy THM-PRE-MEC-100 0 9.882 N/A

10 1 socket holder, B THM-PRE-MEC-106 D 2.079 VESPEL SP-1 0.7300 0.4050 5.40E-05 -120 -0.0076 -0.0055 -0.0031

11 7 mill-max receptacle 1104--0-18-01-30-02-10-0 0.106 BRASS ALLOY 360 0.0710 0.4830 2.05E-05 -120 -0.0029 -0.0002 -0.0014

12 1 curved washer BERG SU-5 0 0.132 302 ST STL 0.4230 0.0100 1.73E-05 -120 -0.0024 -0.0010 0.0000

13 1 peek stub, axb THM-AXB-MEC-804 1 0.035 PEEK 450G 0.3130 0.0800 4.70E-05 -120 -0.0066 -0.0021 -0.0005

14 1 isolation ring THM-AXB-MEC-805 1 0.008 PEEK 450G 0.318 0.02 4.70E-05 -120 -0.0066 -0.0021 -0.0001

15 1 cable holder, axb THM-AXB-MEC-803 1 2.905 BRONZE, 544 PER ASTM-B139-95 0.3150 0.9380 1.80E-05 -120 -0.0025 -0.0008 -0.0024

16 1 spring, cable THM-PRE-MEC-112 A 0.208 BERYLLIUM COPPER, ALLOY C17200 0.1100 0.7500 1.75E-05 -120 -0.0024 -0.0003 -0.0018

17 1 potting compound 0 1.811 EN-11 POTTING COMPOUND 0.6950 0.4890

TOTAL 32.054 gms

PC Board Assembly Data

AXB Preamp Data

Dia Len CTE Min T Delta Dia Delta Len


1 1 board THM-PRE-MEC-101 C 0.768 G10 CIRCUIT BOARD 0.780 0.063 2.16E-05 -120 -0.0030 -0.0024 -0.0002

2 1 TO-99 1 0.931 0.370 0.405

3 8 can insulator THM-PRE-MEC-105 1 0.009 TEFLON 0.050 0.157 1.35E-04 -120 -0.0189 -0.0009 -0.0030

4 1 front shield THM-PRE-MEC-103 1 1.477 TANTALUM PER ASTM-B365-98 0.410 0.066 9.18E-05 -120 -0.0129 -0.0053 -0.0008

5 1 can shield THM-PRE-MEC-104 1 6.624 TANTALUM PER ASTM-B365-98 0.450 0.316 9.18E-05 -120 -0.0129 -0.0058 -0.0041

6 1 ferrule spring THM-PRE-MEC-113 0 0.039 BERYLLIUM COPPER, FULL HARD 0.062 0.315 1.57E-05 -120 -0.0022 -0.0001 -0.0007

7 1 spring plate THM-PRE-MEC-114 0 0.004 BERYLLIUM COPPER, FULL HARD 0.120 0.122 1.75E-04 -120 -0.0244 -0.0029 -0.0030

8 7 MILL-MAX PIN 3112-2-00-34-00-00-08-0 0.030 BRASS ALLOY 360 0.062 0.232 2.00E-05 -120 -0.0028 -0.0002 -0.0006

TOTAL 9.882 gms


Preamp Supporting Slide 2

SPB Preamp DataDia Len CTE Min T Delta Dia Delta Len


1 1 bottom THM-PRE-MEC-108 A 0.361 PEEK 450G 0.8310 0.2510 4.70E-05 -120 -0.0066 -0.0055 -0.0017

2 1 screw fitting THM-PRE-MEC-109 3 6.505 BRONZE, 544 PER ASTM-B139-95 0.9110 0.5050 1.80E-05 -120 -0.0025 -0.0023 -0.0013

3 1 guard THM-PRE-MEC-107 3 1.900 AL ALLOY 6061-T6 PER QQ-A-200/8 0.7720 0.9890 2.34E-05 -120 -0.0033 -0.0025 -0.0032

4 1 top, spb THM-SPB-MEC-801 3 15.850 BRONZE ,544 PER ASTM-B139-95 0.9110 0.5790 1.80E-05 -120 -0.0025 -0.0023 -0.0015

5 1 spring washer THM-PRE-MEC-110 2 0.120 BERYLLIUM COPPER 0.7760 0.0200 1.75E-05 -120 -0.0024 -0.0019 0.0000

6 4 CR-FHM1 0.06-80x0.125x0.125-N 0.041 ST STL 0.1380 0.1250 1.73E-05 -120 -0.0024 -0.0003 -0.0003

7 1 sphere mount, spb THM-SPB-MEC-802 3 0.832 PEEK 450G 0.7000 0.2740 4.70E-05 -120 -0.0066 -0.0046 -0.0018

8 1 ferrule, spb THM-SPB-MEC-805 3 0.323 COPPER TELLURIUM PER ASTM-B301/B301M-99 0.1200 0.2400 1.76E-05 -120 -0.0025 -0.0003 -0.0006

9 1 pc board assy THM-PRE-MEC-100 0 9.882 N/A

10 1 socket holder, B THM-PRE-MEC-106 D 2.079 VESPEL SP-1 0.7300 0.4180 5.40E-05 -120 -0.0076 -0.0055 -0.0032

11 7 mill-max receptacle 1104--0-18-01-30-02-10-0 0.106 BRASS ALLOY 360 0.0720 0.4500 2.05E-05 -120 -0.0029 -0.0002 -0.0013

12 1 curved washer BERG SU-5 0 0.132 302 ST STL 0.4230 0.0100 1.73E-05 -120 -0.0024 -0.0010 0.0000

13 1 peek stub, spb THM-SPB-MEC-804 2 0.022 PEEK 450G 0.3130 0.0400 4.70E-05 -120 -0.0066 -0.0021 -0.0003

14 1 cable holder, spb THM-SPB-MEC-803 2 2.022 BRONZE, 544 PER ASTM-B139-95 0.3150 0.4870 1.80E-05 -120 -0.0025 -0.0008 -0.0012

15 1 spring, cable THM-PRE-MEC-112 A 0.208 BERYLLIUM COPPER, ALLOY C17200 0.1100 0.7500 1.75E-05 -120 -0.0024 -0.0003 -0.0018

16 1 potting compound 0 1.811 EN-11 POTTING COMPOUND 0.6950 0.4890

TOTAL 42.194 gms


Sensor Cable Fabrication

•New procedure synthesized from individual heritage procedures used on FAST, Polar, and Cluster for Cable Fabrication.

•Designed to allow Kevlar braid to take majority of mechanical load.

•Designed to protect majority of fine wires in Custom cable during fabrication, test and usage in orbit.


AXB Cable


SPB Cable


Cable Fabrication

SPB Cable (ETU Fabrication Experience)

AXB Cable

Same as SPB except without Distal Braid Wire (Step 1) and bead (Step 4).

Fabrication Cure

Step Action (hrs) (hrs)

1 Prepare cable & attach Distal Braid Wire 4 82 Attach cable holder 6 83 Solder wires to Socket holder 44 Strip braid and pot bead 4 85 Cut cable to final length & attach inboard connector 6 86 Pour potting compound 1 48


Cable Issues & Status

• AXB & SPB EMU Cables ready for integration into EMU units for thermal/vacuum and vibration testing.• All Gore Cable in house.• EMU Cable Fixtures 90% Complete.

• GENERAL INSPECTION NOTESAll items should be inspected both pre and post test.Of prime concern is the electrical continuity of the cables. The resistance of each lead should be measured and recorded before and after testing.Where possible Preamp functional tests should also be performed pre and post

test.Examine the cable for damage where it exist the Cable Holder.Examine the area around where the cable enters the inboard Airborn connector

potting brackets for signs of pull-out.AXB PREAMP SPECIFIC

Inspect the Preamp for any loosening on the Stacer Tip Flange.Inspect the cable for damage from it’s rapid spooling from the Bobbin.

SPB PREAMP SPECIFICInspect the Bead for signs of pull out or damage and verify that the Distal and Proximal Braids are electrically isolated.Examine the wire loops protruding from the Airborn connector for damage.


Cable Supporting Slide 1

THEMIS Cable Specification

THEMIS Instrument PDR 1 UCB, April 19-20, 2004 Spin Plane and Axial Boom Preamps & Sensor Cable...

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Transcript of THEMIS Instrument PDR 1 UCB, April 19-20, 2004 Spin Plane and Axial Boom Preamps & Sensor Cable...