CINEMA Mechanical Subsystem PDR August 22 2008 David

CINEMA Mechanical Subsystem PDR August 22, 2008 David Glaser/Paul Turin 1 CINEMA PDR- MEC

MECHANICAL -- Overview • Mechanical Requirements • Mechanical Subsystems • Chassis • Solar Array • Communication Hardware • Torque Coils • Sun Sensor • Magnetometer Boom • STEIN • Mass Budget 2 CINEMA PDR- MEC

MECHANICAL – Requirements • Meet Cubesat Interface and Mass Specifications • Withstand Launch Environmental Loads • Keep Internal Magnetic Field to a Minimum • Design • Bus Chassis • House All Components in Bus • STEIN Instrument Attenuating Shutter • Magnetometer Boom Deployment Mechanism • Magnetometer Harness • Harnessing (TBD) 3 CINEMA PDR- MEC

MECHANICAL – Cube. Sat Req. 1. CINEMA must fit inside a P-Pod (Poly-Picosatellite Orbit Deployer) and be deployed without jamming 2. No parts may separate from the satellite (no space debris created) 3. No pyrotechnics allowed 4. Maximum Mass: 3 kg (negotiable? ) 5. Kill Switch, Deployment Switch, and Spring Plungers P-POD CAD Image http: //cubesat. atl. calpoly. edu/pages/reference/pictures. php KC-135 P-POD Test Video http: //cubesat. atl. calpoly. edu/pages/reference/videos. php 4 CINEMA PDR- MEC

MECHANICAL -- Chassis 34 0. 5 100 mm Rails Hard Anodized mm m 00 1 m • 0. 050 inch thick Aluminum Sheet Metal • Ends – ¼ inch Aluminum • Rail Dimensions to Cubesat Specifications 5 CINEMA PDR- MEC

MECHANICAL -- Chassis Spring Plunger Deployment Switch Spring Plunger 6 CINEMA PDR- MEC

MECHANICAL -- Overview Genesat Avionics Box Mag Boom Deployer STEIN Science Radio Transmitter Outboard Magnetometer Components will generally be fastened with a #4 -40 flathead screw, countersunk into chassis. Inboard Magnetometer Sun Sensors 7 CINEMA PDR- MEC

MECHANICAL – Solar Array • 10 Panels (3 on each long side 1 Panel on top, bottom, and short sides) • Each Panel 3 x 3. 2 inches (7. 6 x 8. 1 cm) • Nominal Bus Voltage is 9. 2 V • Therefore need 4 x PV cells on each panel • Typical cells too large • TASC cells are small enough, but require assembly, and have no coverglass 8 CINEMA PDR- MEC

MECHANICAL – Solar Array TASC PV Cells (Spectrolab) 1. 55 cm (. 61 inches) • 20 Cells/Panel • 8 Panels • Cost of Cells: $500 • No Coverglass Included • Cost of Assembly ? 3. 18 cm (1. 25 inches) 9 CINEMA PDR- MEC

MECHANICAL - Communication • Science Data Transmitter • Telemetry Transceiver • 2 Science Data Patch Antennas • 2 Telemetry Patch Antennas 10 CINEMA PDR- MEC

MECHANICAL – Torque Coils located on STEIN Side and Bottom Torque Coil Rail 11 CINEMA PDR- MEC

MECHANICAL – Torque Coils • 28 AWG Magnet Wire (0. 32 mm diam. / max current 1. 4 A) • 62 Turns (50 m of wire) • Coil Length: 0. 317 m Width: 0. 086 m • Effective Coil Area: 0. 0256 m 2 • Electrical Resistance: 10. 65Ω Bus Voltage Current (A) Am 2 Power (W) 7. 5 0. 70 1. 16 5. 28 9. 2 0. 86 1. 42 7. 94 12 CINEMA PDR- MEC

MECHANICAL – Sun Sensors • Field of View Per Sensor: 5° Azimuth x 41° Elevation 2. 3 cm • 2 Sensors @ 45° to Vertical, 90° to Each Other • Sensor: Phototransistor (Motorola MRD 300) • Prototype Tested • Load Resistor: 1 kΩ • Vcc = 5 V • Power: ~25 m. W (Light); ~10µW (Dark) 1. 6 cm CINEMA PDR- MEC 13

MECHANICAL – Sun Sensors Prototype Scanned Across Sun @ 1 RPM Averaged Data 4. 6° > 1 Volt Nominal 1. 4° Width of Opening Simulation of Earthshine Rise Time ~120 ms 14 CINEMA PDR- MEC

MECHANICAL – Sun Sensors Raw Data Large Noise Peaks Probably Due to DC Motor Noise ~ -0. 3 V Slope of Rise: ~ 35 V/sec Timing Error = 9 ms < 0. 1° 15 CINEMA PDR- MEC

MECHANICAL – Mag & Boom 16 CINEMA PDR- MEC

MECHANICAL – Mag & Boom • 1 meter stacer boom • Held by Ti. Ni P 5 Pin Puller • Magnetometer in 2 x 2 cm compartment • Magnetometer Harness • 18 strands of 36 AWG magnet wire • Aracon braid for Harness Jacket • Non-Magnetic Braid on 6 cm closest to sensor • Fixed to Mag Mount and Base of Boom via Screw-Down Fixtures • 18 -pin Connector at End 17 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Magnetometer Mount Magnetometer Chassis Mounts 18 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Ti. Ni Pin Puller Stowed Stacer Boom Release Pin 19 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Harness Details Harness Constraining Fixtures String Cannister 20 CINEMA PDR- MEC

MECHANICAL – Mag & Boom 21 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Harness Assembly 22 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Anti-vibration Clearance 0. 02 inches (0. 5 mm) 23 CINEMA PDR- MEC

MECHANICAL – Mag & Boom Prototype Harness • 36 AWG Magnet Wire with Polythermalize Insulation • Examined for Wear Under Microscope • 18 Strands Wound with a winding machine, 1 turn/cm • Tension on cable not controlled • Inserted into Aracon Braid • Harness Deploy Tested on Mockup Boom 24 CINEMA PDR- MEC

MECHANICAL – Mag & Boom & Harness Mock Up – Stowed Configuration ID 2. 54 cm Annulus 3. 8 mm 25 CINEMA PDR- MEC

MECHANICAL – Mag & Boom & Harness Mock Up – Deployment Test Video (half speed) 26 CINEMA PDR- MEC

MECHANICAL -- STEIN • Collimator: 40° x 60° FOV • High Voltage Plates: 4 mm separation, ~1 cm from detector • Attenuator: Swinging Shutter with Be. Cu Foil • Actuated by Two SMA “Nanomuscles” • Flight Heritage from THEMIS and other Missions • Low Electrical and Magnetic Noise • Microswitch Overcenter Mechanism 27 CINEMA PDR- MEC

MECHANICAL -- STEIN Collimator Attenuator Detector and Electronics 28 CINEMA PDR- MEC

MECHANICAL -- STEIN Collimator 60° Electric Field Plates 29 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Shutter with Be. Cu Foil 4 Pixel Detector 30 CINEMA PDR- MEC

MECHANICAL -- STEIN Actuators – Shutter Closed Nanomuscle Actuator Pivot Lever Countermass Capton Yoke Cam/Lever 31 CINEMA PDR- MEC

MECHANICAL -- STEIN Actuators – Shutter Open 32 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Overcenter Mechanism HM Microswitch Spring Plunger Cam Bearing 33 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Mechanism Specifications Nanomuscle Nominal Stroke Max. Force Spring-Loaded Lever 4 mm 70 g (0. 69 N) 5. 92 35° Roller Displacement 0. 89 mm Plunger Displacement Nanomuscle Lever Pivot Angle Mech. Advantage 0. 79 mm Spring Rad. w/ 4 mm stroke 6. 55 mm Spring Constant 0. 17 N/mm Rad. w/ 3. 5 mm stroke 5. 73 mm Free Length 15. 75 mm Microswitch Actuation Force ~0. 98 N Spring Constant ~0. 5 N/mm Operating Stroke 0. 15 mm 34 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Mechanism Analysis Maximum Torque from Nanomuscle and Lever Stroke Lever Radius Tmax (m. Nm) FOS 4 3. 5 5. 73 3. 95 0. 99 4 6. 55 4. 52 1. 13 35 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Overcenter Mechanism – Cam Analysis 36 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Overcenter Mechanism – Cam Analysis 37 CINEMA PDR- MEC

MECHANICAL -- STEIN Attenuator Mounting – How to Locate These Components 38 CINEMA PDR- MEC

MECHANICAL -- STEIN 1. Attenuator Mounting – Collimator Shell 39 CINEMA PDR- MEC

MECHANICAL -- STEIN 2. Attenuator Mounting – Add Mount Plate 40 CINEMA PDR- MEC

MECHANICAL -- STEIN 3. Attenuator Mounting – Add Shutter and Actuators 41 CINEMA PDR- MEC

MECHANICAL -- STEIN 4. Attenuator Mounting – Add Switch Mounts 42 CINEMA PDR- MEC

MECHANICAL -- STEIN 5. Attenuator Mounting – Add Switches #0 -80 Set Screw for Switch Location Adjustment 43 CINEMA PDR- MEC

MECHANICAL – Mass Budget Subsystem/Part Proposal PDR Chassis 470 463 Solar Arrays 375 MAG Boom System 113 156 Sun Sensors 10 10 Antennas 15 165 1 battery pack 950 2 battery packs ? ? Transmitter 70 70 Torque Coils 50 85 STEIN Detector Head 70 146 STEIN Electronics 90 90 STEIN HVPS 150 MAG Electronics 45 45 Instrument Digital 90 90 Instrument LVPS 150 Harnessing 60 60 Thermal 50 50 2758 3055 Genesat Avionics Total CINEMA PDR- MEC Highlighted figures Have changed since the proposal. Most other figures are rough estimates. 44