DINO CDR Thermal 2252021 Thermal Subsystem CDR March
DINO CDR – Thermal 2/25/2021 Thermal Subsystem CDR March 13, 2004 Robin Hegedus Nicole Demandante Josh Stamps
DINO CDR – Thermal 2/25/2021 Objective • The thermal team seeks to maintain all components within their temperature limits for all modes of operation. Colorado Space Grant Consortium 2
DINO CDR – Thermal 2/25/2021 Current Requirements Temperature Ranges Flight Comp 0 C 40 C Radio -20 C 60 C HOP -60 C 65 C Lithium Batteries 0 C 40 C PCB 0 C 50 C Battery Panel - S/C Interface Max 30 C difference Colorado Space Grant Consortium 3
DINO CDR – Thermal 2/25/2021 Discussion Outline • • • Summary of progress at PDR Changes in design since PDR Design Plan Control Devices to be utilized What’s Left Plan of Action Colorado Space Grant Consortium 4
DINO CDR – Thermal 2/25/2021 PDR Summary-Design Plan (Phase 1) • The design plan was to have a general model completed by mid-February. – all heat sources – General conduction model – General radiation model • Status as of PDR – Roughly half of the conduction model was complete – A quarter of the radiation model was complete – Much of the physical satellite was finalized at PDR Colorado Space Grant Consortium 5
DINO CDR – Thermal 2/25/2021 PDR Summary-Design Plan (Phase 2) • Between mid-February and CDR – control devices would be selected based on projected temperature range endured by DINO. • • Temperature Sensors MLI Blankets Radiator Possibly Heaters • Status as of PDR – Approximately 30 temp sensors would be utilized. – MLI blankets could be purchased or assembled Colorado Space Grant Consortium 6
DINO CDR – Thermal 2/25/2021 Obstacles – Computer Crash • Computer Crash – TAK currently unlicensed – Current Model has been lost • Problem was anticipated – Hardware/Software failures randomly disabled computer terminal between December and March. – Plan B already determined by time of crash. – Funding gathered by time of crash. Colorado Space Grant Consortium 7
DINO CDR – Thermal 2/25/2021 What was Plan B? • New software to replace TAK III: – Ideal Software Abilities • Upload structure drawings directly. • Model variable heat sources and accurate conduction models. • Model radiation heat transfer for orbiting satellite. – Three solutions considered • Replace TAK III • Thermal Desktop (SINDA) • Cosmos. WORKS Colorado Space Grant Consortium 8
DINO CDR – Thermal 2/25/2021 Software Comparison Software Heat Gen. / Conduction Radiation Direct Upload Cost TAK III Yes No No Moderate Thermal Desktop (SINDA) Yes Yes High Cosmos Works Yes No Yes Low Colorado Space Grant Consortium 9
DINO CDR – Thermal 2/25/2021 Software Solution • Thermal Desktop exhibited the best performance characteristics. – Direct upload of SOLIDWORKS drawings. – Simulation of Radiation Heat Transfer for a satellite with Rad. CAD component. – Visual illustration of satellite temperatures at given time. • About that cost? – EEF Grant was accepted to cover cost of auto. CAD. – C&R Technologies donated the Thermal Desktop Package, waiving 80% of the overall cost. – The discovery of an on-campus CAD provider allowed for a 90% reduction in the cost of the auto. CAD 2004 program. Colorado Space Grant Consortium 10
DINO CDR – Thermal 2/25/2021 Post-PDR Summary • Phase 1 of Post-PDR plan failed with the computer. • Phase 2 was still on track with new software available at time of crash. • Thermal Device Selection determined: – Temperature Sensors – MLI Blankets Colorado Space Grant Consortium 11
DINO CDR – Thermal 2/25/2021 Thermal Strategy • ISO-Grid Frame allows for convenient analysis. – Side-panels isolated from one another. – Potential heat paths are minimal. – Easy dumping of excess heat to radiator on Nadir Plate if necessary. – Mounting of devices can be manipulated with insulative washers or variable interface areas so as to create isothermal enviornment. • Side Panels can be controlled independently. Colorado Space Grant Consortium 12
DINO CDR – Thermal 2/25/2021 Controlling Battery Panel • Battery Panel – Structure design minimizes external heat transfer to sensitive battery cells and circuitry. – Possibly heaters will be required. – External Surface could be painted to minimize/maximize radiation heat transfer. Colorado Space Grant Consortium 13
DINO CDR – Thermal 2/25/2021 Controlling Side Panels • Sides with Solar Panels – Back of Solar Panel provides heat that must be transferred away in order to preserve efficiency of Solar Panels. – Excess heat can be transferred to radiator, or to ‘cold’ parts of satellite. – Devices mounted on these sides can be isolated from heat generated by solar panels by use of isolating washers or by minimizing their interface area. • Sides without Solar Panels – MLI covers frame to prevent direct radiation exposure, and to provide an adiabatic environment for devices mounted on panel. Colorado Space Grant Consortium 14
DINO CDR – Thermal 2/25/2021 Controlling Nadir Plate • Most complex of all panels in terms of heat. – Science cameras have narrow operating range – Radiator mounted on this panel – Lightband • Frame will be protected by MLI to prevent direct radiation from entering/exiting satellite. • Cameras will be isolated from frame with insulative material. Possible Heaters will be used. Colorado Space Grant Consortium 15
DINO CDR – Thermal 2/25/2021 Testing/Monitoring Design • Temperature Sensors required – Verify Model during testing by monitoring temperature gradients throughout satellite. – Monitor temperature of critical devices onboard DINO while in orbit. • Enabling Active Control – Knowledge of accurate temperature measurements of devices during orbit allows for troubleshooting potential failures. Colorado Space Grant Consortium 16
DINO CDR – Thermal 2/25/2021 Temperature Sensors Needed Local Temperatures (28): – Battery Panel/Satellite Interface (12) – Side Panel/Nadir Plate Interface (6) – Body Mounted S. Panel (4) – Science Cameras (2) – Radios (1) – 27 V Battery Pack (1) – Magnetometer (1) – Tip Mass Comm (1) Device Temperatures (4): – – ADCS Circuitry (1) Flight Computer (1) C&DH Circuitry (1) TNC/Radio Circuitry (1) Devices already monitored – – – Colorado Space Grant Consortium Battery Cells HOPS Frangibolts EMC Hinges FITS Sensors 17
DINO CDR – Thermal 2/25/2021 Sensor Requirements • Monitoring Temperature Gradients – 30+ sensors desired • Cost Effective – Temperature Differences Measured • Linearity more important than accuracy – Wide Temperature Range • Monitoring Sensitive Equipment – High Accuracy Desired – Appropriate Temperature Range – Mountability Colorado Space Grant Consortium 18
DINO CDR – Thermal 2/25/2021 Sensor Options • Four Basic Types: – – Thermocouples Thermistors RTD’s IC’s Colorado Space Grant Consortium 19
DINO CDR – Thermal 2/25/2021 Temperature Sensor Comparison Sensor Advantages Disadvantages Thermistor High Output Fast Non-Linear Limited Range Current Source Required Thermocouple Self-Powered Inexpensive Wide-Temp Range Non-Linear Low-Voltage RTD Most Accurate More Linear than couple Expensive Current Source Required IC Very Accurate Most Linear Inexpensive Voltage Source Required Narrow Range Colorado Space Grant Consortium 20
DINO CDR – Thermal 2/25/2021 Temperature Sensor Comparison Device Input Output Accuracy Range Linearity (Rank) Cost (Rank) Thermocouple (T -Type) Temperature (Self – Powered) Voltage (0. 042 m. V/ °C) ± 1° C -270 °C 350 °C 4 1 Thermistors Current Source Resistance ± 0. 2° C -100 °C 250 °C 3 3 RTD’s Current Source Resistance ± 0. 01% -250 °C 650 °C 2 4 IC’s (AD 590) Voltage Source (4 -30 V) Current (1 µA/ °C) ± 0. 05 °C -50 °C 1 2 Colorado Space Grant Consortium 21
DINO CDR – Thermal 2/25/2021 Sensor Selection • Thermocouple – For measuring temperature gradients thermocouple is preferred. – Low Cost – Wide Temperature Range – NO INPUT REQUIRED • IC’s – – – For measuring devices, IC’s are preferred Low Cost High Accuracy Appropriate Temperature Range Wide Input Range Colorado Space Grant Consortium 22
DINO CDR – Thermal 2/25/2021 Thermocouple Selection Parameters Type Material Accuracy Cost (50 ft) J Iron Constantan ± 0. 04° C $13 K Chromium Aluminum ± 2. 2° C $23 T Copper Constantan ± 1° C $14 E Chromium Constantan ± 1. 7° C $31 Acquired from NIST database Colorado Space Grant Consortium 23
DINO CDR – Thermal 2/25/2021 Thermocouple Selection • Type T- Copper. Constantan Thermocouple Input Temperature Output . 042 m. V/°C Accuracy ± 1°C Range -270 to 350 °C Linearity ± 3°C Cost $14 for 50 ft. Colorado Space Grant Consortium 24
DINO CDR – Thermal 2/25/2021 Device Temperature Sensors Integrated Circuit Sensors • AD 590 - Two-terminal (Voltage In/Current Out) integrated circuit temperature transducer. Characteristic Wide Temp. Range Value -55 to 150 °C Accuracy ± 0. 5 °C Linear Current Output 1 μA / °C Excellent Linearity ± 0. 3 °C Wide Supply Range Low Cost Colorado Space Grant Consortium 4 V to 30 V $1. 25 to $3. 50 25
DINO CDR – Thermal 2/25/2021 Multilayer Insulation (MLI) • MLIs will be used to keep DINO as isothermal as possible by creating an adiabatic surface Colorado Space Grant Consortium 26
DINO CDR – Thermal 2/25/2021 Outer Layer • Purpose – – Protect Against Space Exposure Maintain Temperature Provide ESD Prevention Provide Atomic Oxygen and Micrometeoroid Protection • Material – Kapton – Teflon FEP Colorado Space Grant Consortium 27
DINO CDR – Thermal 2/25/2021 Inner Layer • Purpose – Decrease the heat transfer through the blanket • Materials – Mylar • Can be bought cheap – Dacron or some sort of mesh • Wedding Veils have been used before • Used to separate the layers of Mylar and minimize the amount of conduction between layers Colorado Space Grant Consortium 28
DINO CDR – Thermal 2/25/2021 Construction of MLI • Materials Needed – Will need Mylar for the inner layers – Velcro for mounting – Rest of the material will be determined in the future based on prices and material properties • Plan to build MLIs in-house – Hope to get some more help from Ball Aerospace – Will be great educational experience for all involved Colorado Space Grant Consortium 29
DINO CDR – Thermal 2/25/2021 Construction Objectives • • Minimize effect of seams and gaps Provide vent paths Optimize number of layers Maximize loft Colorado Space Grant Consortium 30
DINO CDR – Thermal 2/25/2021 Application Of MLI • All surfaces which emit or receive radiation – – – Between side panels Behind deployable panel Nadir Panel Tip-Mass Exceptions • • Radiator Solar Panels Battery Assembly Camera Colorado Space Grant Consortium 31
DINO CDR – Thermal 2/25/2021 The Future of MLIs on DINO • We still need to determine the materials that are going to be used for all of the layers • Need to determine the number of layers – Number of layers will be determined by the effective emissivity required to keep DINO at the required temperatures – This will be found from thermal model Colorado Space Grant Consortium 32
DINO CDR – Thermal 2/25/2021 Testing Plan • Minimal research done thus far – Hope to use Ball Aerospace Advice in developing test plan. • Vision – Thermal Vacuum Testing – Manipulate Heat Environment while monitoring temperature distribution throughout DINO. Colorado Space Grant Consortium 33
DINO CDR – Thermal 2/25/2021 What’s Left for Thermal • • Possible Heaters for cameras/batteries Complete MLI Plan Obtain/Design/Calibrate Thermocouples Begin/Complete New Thermal Model Size Radiator Obtain Insulative Washers Test Plan Colorado Space Grant Consortium 34
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