TRIO-CINEMA 1 UCB, 2/08/2010 CINEMA Mechanical Systems David Glaser Mechanical Engineering Space Sciences Laboratory University of California, Berkeley

TRIO-CINEMA 2 UCB, 2/08/2010 Mechanical Systems Agenda AGENDA Exterior Structure (Spacecraft Chassis) Avionics Stack Structure Thermal Design Harnessing Design Each Section Will Include: Overview Requirements Design Outstanding Issues Development Plan

TRIO-CINEMA 3 UCB, 2/08/2010 Mechanical Systems - Exterior Structure Exterior Structure

TRIO-CINEMA 4 UCB, 2/08/2010 External Structure Overview

TRIO-CINEMA 5 UCB, 2/08/2010 Structure Requirements Level 2 Structure MEC-01Cubesat3U Cubesat form factor per Cubesat Specification MEC-03Strength/VibrationCompatible with Cubesat standard and launch vehicle supporting payload

TRIO-CINEMA 6 UCB, 2/08/2010 Exterior Structure Design Top and Sides 5052-H32 Al Sheet Metal.048 inches thick Ends ¼ inch 6061 T6 Al Cutouts for Mass Reduction – (May Be Eliminated for Radiation Shielding) 3U Corners will be hard anodized per CubeSat Specification All Dimensions Meet CubeSat Specification

TRIO-CINEMA 7 UCB, 2/08/2010 Exterior Structure Design Sheet Metal Parts Fastened Together with 4-40 Flathead Screws and PEM nuts PEM nuts will also be used in some places to fasten components to the chassis wall

TRIO-CINEMA 8 UCB, 2/08/2010 Exterior Structure Design CubeSat On-Off Switch Requirements Remove-Before-Flight Pin Prevents Accidental Power Up Deployment Switch (Honeywell hermetically sealed switch) Closes When P-POD Door Opens

TRIO-CINEMA 9 UCB, 2/08/2010 Exterior Structure Issues 1.Unproven Chassis Design – To our knowledge, no other CubeSats have used this type of chassis and fastening method 2.Possible Interference between PEM nuts and Avionics Stack Boards – TBD when all boards are specified – Screws and holes will be moved if there is interference 3.Should mass reduction cutouts be used or not?

TRIO-CINEMA 10 UCB, 2/08/2010 Exterior Structure Development Plans Final Design Changes – February 2010 In-House Fabrication By SSL Machine Shop March- April 2010 Assemble and Test May 2010 Test Integration with Spacecraft Components (Summer 2010) Performance Test In Spacecraft Level Vibration Test (Fall 2010)

TRIO-CINEMA 11 UCB, 2/08/2010 Mechanical Systems - Exterior Structure Avionics Structure

TRIO-CINEMA 12 UCB, 2/08/2010 Avionics Structure Overview

TRIO-CINEMA 13 UCB, 2/08/2010 Structure Requirements Level 2 Structure MEC-05Avionics ModuleProvide structural integrity to the avionics board stack Avionics ModuleAllows passage of all harnessing between boards and to and from components external to the stack

TRIO-CINEMA 14 UCB, 2/08/2010 Avionics Structure Design BoardNominal Component Height HVPS1.10 in. (28 mm.)* MAGIC0.6 in. (15.24 mm) Instrument Interface/LVPS0.6 in. (15.24 mm) Helium UHF Radio0.6 in. (15.24 mm) Clyde 3U Battery0.98 in. (25 mm)* Clyde EPS0.6 in. (15.24 mm) Processor0.6 in. (15.24 mm) Thickness of 7 Boards (.06 in. each)0.42 in (10.7 mm) Total Height5.47 in. (140 mm) Available Stack Height: 145 mm PC-104 Standard Connectors is 0.6 inch Space between boards Each board is.06 inches thick *Non-standard board height

TRIO-CINEMA 15 UCB, 2/08/2010 Avionics Structure Design Seven PC-104 Boards Connected Via PC-104 Male –Female Standoffs Electrical Connections via PC-104 Connector (Except HVPS board)

TRIO-CINEMA 16 UCB, 2/08/2010 Avionics Structure Issues Possible interference between components on PC-104 boards – need to map where higher components are on each board If height limitation is surpassed, may need to move one or two batteries out of the stack

TRIO-CINEMA 17 UCB, 2/08/2010 Avionics Structure Development Plans Development Evaluation of head and foot-room of board components February-March 2010 In-House Fabrication of Parts by SSL Machine Shop, March-April 2010 Integration with 7 PC-104 Boards (May? 2010) Integration with CINEMA Chassis and harnessing (Summer 2010) Performance Test In Spacecraft Level Vibration Test (Fall 2010)

TRIO-CINEMA 18 UCB, 2/08/2010 Mechanical Systems - Exterior Structure Harnessing

TRIO-CINEMA 19 UCB, 2/08/2010 Harnessing Overview Make electrical connections between avionics boards Make electrical connections between avionics stack and all instruments, and other components

TRIO-CINEMA 20 UCB, 2/08/2010 Harnessing Requirements Level 2 Telecom TEL-03 RF Harnessing Accommodate coax from transmitter/transceiver to splitters, from splitters to patch antennas Level 3 MAGIC Boom & OB Sensor BOM-04OB MAG Harness Supports an 18-conductor (36 AWG magnet wire) shielded harness (captured to OB sensor, Connector on MAGIC board end). Able to withstand the forces from being stored in a coil and deployed several times. Level 3 STEIN Preamp/Shaper SFE-08Interfaceparallel harness to FPGA board (or serial interface using small FPGA on ADC board - TBD) Few harnessing requirements have been defined

TRIO-CINEMA 21 UCB, 2/08/2010 Harnessing Design Design is mostly incomplete What has been done: MAGIC harness (between MAGIC board and sensor) has been designed and ETU built/tested (more info later) Have begun discussions with John Sample on the HVPS board connector and its routing Solar Panel to EPS connectors have been defined Other?

TRIO-CINEMA 22 UCB, 2/08/2010 Harnessing Issues No known issues yet

TRIO-CINEMA 23 UCB, 2/08/2010 Harnessing Development Plans Development Requirements should be developed – February 2010 As the seven boards in the avionics stack become available a harnessing scheme will be worked out – February-April 2010 Recommend meetings to discuss this begin immediately

TRIO-CINEMA 24 UCB, 2/08/2010 Mechanical Systems - Thermal Thermal Design

TRIO-CINEMA 25 UCB, 2/08/2010 Thermal Overview Thermal Design Approach is to create a simple model of the heat inputs and outputs through the satellite surface and critical instrument surfaces

TRIO-CINEMA 26 UCB, 2/08/2010 Thermal Requirements Level 2 Structure MEC-04ThermalProvide passive thermal design utilizing thermal finishes on surfaces not covered by solar array. Transfer heat away from power dissipaters to bus (particularly transmitter, which needs ~100g heat sync)

TRIO-CINEMA 27 UCB, 2/08/2010 Thermal Design We have only just begun to make a thermal model of the satellite. Early approach: modify spreadsheet made for THEMIS by Dave Pankow Model of tumbling spacecraft needed, in a addition to spinning at ecliptic-normal Pankow did analysis of deployed magnetometer Possible surfaces include black anodize, white paint, MLI S-Band Transmitter and DC-DC converters both dissipate significant power – will be mounted to chassis wall

TRIO-CINEMA 28 UCB, 2/08/2010 Thermal Analysis Results Magnetometer Analysis – D. Pankow Combination of white and black surfaces would create best temperature range Harness may alter mag temperature by a few degrees Stacer boom will be thermally isolated and have a moderate temperature range

TRIO-CINEMA 29 UCB, 2/08/2010 Thermal Analysis Results Spacecraft level model – no results yet, but note that upper and lower surfaces of satellite have large areas of aluminum wall exposed – careful choice of surface materials will be needed S-Band Transmitter and DC-DC converters both dissipate significant power – will be mounted to chassis walls

TRIO-CINEMA 30 UCB, 2/08/2010 Thermal Issues We have no thermal specifications for the patch antenna dielectric material (Rogers RT/Duroid 6002). For now we are treating it as a grey painted surface.

TRIO-CINEMA 31 UCB, 2/08/2010 Thermal Development Plans Lots of work ahead: Spacecraft level model in Excel will be completed in early February Need to include Earth IR emission Need to include a tumbling mode A thermal model and design of STEIN is needed to ensure that the detector remains as cool as possible A thermal model of the torque coils is also warranted, as large temperature fluctuations would alter coil resistance and therefore magnetic dipole of the coils All thermal models will be reviewed by Chris Smith, SSL thermal engineer Thermal Desktop (FEA) models will be created if necessary

TRIO-CINEMA 32 UCB, 2/08/2010 Mechanical Systems – Magnetometer Magnetometer Mechanical

TRIO-CINEMA 33 UCB, 2/08/2010 Magnetometer Mechanical Overview Stacer boom (flight spare from FAST mission) Stowed Magnetometer

TRIO-CINEMA 34 UCB, 2/08/2010 Magnetometer Mechanical Requirements Level 3 MAGIC Boom & OB Sensor BOM-01Length>1m BOM-03ActuationActuated by a SMA controlled by the C&DH via a switched bus voltage power service BOM-04OB MAG HarnessSupports an 18-conductor (36 AWG magnet wire) shielded harness (captured to OB sensor, Connector on MAGIC board end). Able to withstand the forces from being stored in a coil and deployed several times. BOM-05OB MAG Mechanical Supports a 25g OB MAG sensor per the MAGIC ICD BOM-06OB MAG ThermalOB sensor to be thermally isolated from stacer and passively thermally controlled by the surface properties between -120 and +50C )TBR) BOM-07MAGIC Boom+sensor+harn ess mass ~160g BOM-08Boom DeploymentStow magnetometer and Stacer boom within the space provided; Deploy Magnetometer to 1 m distance with a single, one-shot actuation;

TRIO-CINEMA 35 UCB, 2/08/2010 Magnetometer Mechanical Design 18 Twisted Conductors 36 AWG Magnet Wire with Flight Heritage Aracon Braided Jacket – Silver/Nickel Harness Design

TRIO-CINEMA 36 UCB, 2/08/2010 Magnetometer Mechanical Design Spans the width of the CINEMA chassis Mounted to walls with screws Mag extends out < 6.5 mm from outer wall Mag Boom Design TiNi

TRIO-CINEMA 37 UCB, 2/08/2010 Magnetometer Mechanical Design Kickoff Spring Potted Sensor in housing

TRIO-CINEMA 38 UCB, 2/08/2010 Magnetometer Mechanical Test Results 1.ETU Harness has been tested for insulation breakdown after extreme bending tests 2.Force Ratio on Pinpuller is 3.3 minimum. 3.ETU Mag Boom has been assembled with mock sensor mass and deployed 11 times Students have successfully assembled it 4.Twice the release pin experienced binding and pin/bushing interface was redesigned and lubrication added – four consecutive successful deployments since redesign 5.Deployment forces on harness seem to be minimal 6.ETU Mass: 210 g (50 g more than requirement)

TRIO-CINEMA 39 UCB, 2/08/2010 Magnetometer Mechanical Test Results Sample Test Video

TRIO-CINEMA 40 UCB, 2/08/2010 Magnetometer Mechanical Issues Binding of release pin Will continue to monitor during subsequent tests Need to define reliability requirement Fragility of harness braided jacket need to develop better handling procedures and reliability requirement Boom length appears to be < 1 m (~0.90 m). MAGIC team has said this is fine as long as they know the exact deployed length MAGIC team wants to assure that deployment shock will not exceed instrument limitations Thermal design needs to be finalized – surface materials (mentioned earlier in Thermal presentation)

TRIO-CINEMA 41 UCB, 2/08/2010 Magnetometer Mechanical Development Plans Development Deployment shock test with STM supplied by MAGIC team – spring 2010 Possible Vibe Test (Piggyback on RBSP test) Feb- March 2010 Fabrication of Flight Model Parts – April-May 2010 Integration with CINEMA Chassis (Summer 2010) Performance Test In Spacecraft Level Vibration and Thermal Vac Tests (Fall 2010)

TRIO-CINEMA 42 UCB, 2/08/2010 Mechanical Systems - STEIN STEIN Mechanical David Glaser

TRIO-CINEMA 43 UCB, 2/08/2010 STEIN Mechanical Overview

TRIO-CINEMA 44 UCB, 2/08/2010 STEIN Mechanical Requirements STE-07STEIN FOVCharged particle FOV 40 degrees by 70 degrees. Two-pi glint free FOV STE-08Stray LightPrevent stray light from getting to the detector from any direction, including from the back (sensitive to 1E-6 suns) STE-09STEIN DefelectorsHigh voltage surfaces shall be no less than 2 mm away from other surfaces; STE-10STEIN Scattered Electrons Surfaces near the electron trajectories shall be formed to reduce scattered electrons STE-11STEIN Mass~260g for detector head (excludes electronics, HVPS) COL-01CollimationProvide better than 1E-6 sunlight rejection up to 40 degrees (TBR) from bore-sight in spin direction

TRIO-CINEMA 45 UCB, 2/08/2010 STEIN Mechanical Design Baffles and housing interior are blackened

TRIO-CINEMA 46 UCB, 2/08/2010 STEIN Mechanical Design Attenuator Mechanism is Modular STEIN Assembly

TRIO-CINEMA 47 UCB, 2/08/2010 STEIN Mechanical Design Electrostatic Deflector inch thick BeCu blades sandwiched between.025-inch thick Aluminum clamps Blades are Cu plated and blackened with Ebanol C

TRIO-CINEMA 48 UCB, 2/08/2010 STEIN Mechanical Test Results Mass of ETU Sensor Head: ~250 g (meets requirement) Attenuator is easily mounted to and removed from housing Deflection plates mount easily into housing Original deflectors scattered many electrons - redesigned No HV arcing was observed in vacuum chamber tests with original deflectors New deflectors have been assembled but not yet tested

TRIO-CINEMA 49 UCB, 2/08/2010 STEIN Mechanical Design New Electrostatic Deflector Design inch thick BeCu blades sandwiched between.025-inch thick Aluminum clamps Blades are Cu plated and blackened with Ebanol C

TRIO-CINEMA 50 UCB, 2/08/2010 STEIN Mechanical Design Electrostatic Deflector New design is wider to eliminate edge effects Old Flat Plate Design

TRIO-CINEMA 51 UCB, 2/08/2010 STEIN Mechanical Issues 1.New deflection system needs to be tested in vacuum chamber 2.Need to test blocking of stray visible light 3.End clamps on electrostatic deflectors flex too much – solution is to add third fastener in the middle and/or make parts from stainless steel 4.Should baffles be fastended with epoxy or screws? 5.Thermal requirements/modeling/design needed 6.Assembly procedure of detector board and signal processing boards has not been defined

TRIO-CINEMA 52 UCB, 2/08/2010 STEIN Mechanical Development Plans Development New deflection system to be tested - Feb Add second side of deflection and test - March 2010 Integrate baffles with epoxy and test light-tightness – April 2010 Final design changes for flight – March 2010 Fabricate Flight Parts – May 2010 Assemble and Test Flight Model – June-July 2010 Performance Test In Spacecraft Level Vibration Test (Fall 2010)