Spacecraft Thermal Control

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2 Spacecraft Thermal Control February 17-18, 2010 Beltsville, Maryland $990 (8:30am - 4:00pm) "Register 3 or More & Receive $ each Off The Course Tuition." Summary This is a fast paced two-day course for system engineers and managers with an interest in improving their understanding of spacecraft thermal design. All phases of thermal design analysis are covered in enough depth to give a deeper understanding of the design process and of the materials used in thermal design. Program managers and systems engineers will also benefit from the bigger picture information and tradeoff issues. The goal is to have the student come away from this course with an understanding of how analysis, design, thermal devices, thermal testing and the interactions of thermal design with the overall system design fit into the overall picture of satellite design. Case studies and lessons learned illustrate the importance of thermal design and the current state of the art. Instructor Douglas Mehoke is the Assistant Group Supervisor and Technology Manager for the Mechanical System Group in the Space Department at The Johns Hopkins University Applied Physics Laboratory. He has worked in the field of spacecraft and instrument thermal design for 30 years, and has a wide background in the fields of heat transfer and fluid mechanics. He has been the lead thermal engineer on a variety spacecraft and scientific instruments, including MSX, CONTOUR, and New Horizons. He is presently the Technical Lead for the development of the Solar Probe Plus Thermal Protection System. What You Will Learn How requirements are defined. Why thermal design cannot be purchased off the shelf. How to test thermal systems. Basic conduction and radiation analysis. Overall thermal analysis methods. Computer calculations for thermal design. How to choose thermal control surfaces. When to use active devices. How the thermal system interacts with other systems. How to apply thermal devices. Course Outline 1. The Role of Thermal Control. Requirements, Constraints, Regimes of thermal control. 2. The basics of Thermal Analysis, conduction, radiation, Energy balance, Numerical analysis, The solar spectrum. 3. Overall Thermal Analysis. Orbital mechanics for thermal engineers, Basic orbital energy balance. 4. Model Building. How to choose the nodal structure, how to calculate the conductors capacitors and Radfacs, Use of the computer. 5. System Interactions. Power, Attitude and Thermal system interactions, other system considerations. 6. Thermal Control Surfaces. Availability, Factors in choosing, Stability, Environmental factors. 7. Thermal control Devices. Heatpipes, MLI, Louvers, Heaters, Phase change devices, Radiators, Cryogenic devices. 8. Thermal Design Procedure. Basic design procedure, Choosing radiator locations, When to use heat pipes, When to use louvers, Where to use MLI, When to use Phase change, When to use heaters. 9. Thermal Testing. Thermal requirements, basic analysis techniques, the thermal design process, thermal control materials and devices, and thermal vacuum testing. 10. Case Studies. The key topics and tradeoffs are illustrated by case studies for actual spacecraft and satellite thermal designs. Systems engineering implications. 28 Vol. 100 Register online at or call ATI at or

3 Boost Your Skills with On-Site Courses Tailored to Your Needs The Applied Technology Institute specializes in training programs for technical professionals. Our courses keep you current in the state-of-the-art technology that is essential to keep your company on the cutting edge in today s highly competitive marketplace. Since 1984, ATI has earned the trust of training departments nationwide, and has presented on-site training at the major Navy, Air Force and NASA centers, and for a large number of contractors. Our training increases effectiveness and productivity. Learn from the proven best. For a Free On-Site Quote Visit Us At: For Our Current Public Course Schedule Go To:

4 Spacecraft Thermal Control 2 WHY DO WE NEED THERMAL CONTROL IN SPACECRAFT UNCONTROLLED TEMPERATURES CAN BE VERY COLD OR VERY HOT TYPICAL ELECTRONICS ARE NORMALLY DESIGNED TO OPERATE AT ROOM TEMPERATURE SOME COMPONENTS, SUCH AS CRYOGENIC EQUIPMENT, MAY REQUIRE SPECIAL TEMPERATURE ENVIRONMENTS RELIABILITY IS ENHANCED BECAUSE OF REDUCED THERMAL WORKING STANDARD COMPONENTS CAN BE DESIGNED IF THE OPERATING ENVIRONMENT IS KNOWN

5 Spacecraft Thermal Control 3 DESIGN REQUIREMENTS DESIGN TEMPERATURES MISSION BOUNDARIES ENVIRONMENTS ORBIT STABILIZATION LIFETIME PHYSICAL CONFIGURATION OPERATIONAL MODES OTHER ESD COST WEIGHT

6 Spacecraft Thermal Control 4 THERMAL ANALYSIS THE THERMAL DESIGN OF A SPACECRAFT IS ACCOMPLISHED BY BOTH TEST AND ANALYSIS ANALYSIS FIRST CONFIRMS THAT A DESIGN IS FEASIBLE AND THEN TEST IS USED TO CONFIRM THE FINAL DESIGN THE ANALYSIS OF A SPACECRAFT IS BASED ON THE FIRST LAW OF THERMODYNAMICS THIS ANALYSIS WILL INCLUDE MODEL BUILDING» CONDUCTION» RADIATION» THERMAL CAPACITY ENVIRONMENTAL HEAT INPUTS OPERATIONAL MODES ORBITAL HEAT BALANCE

7 Spacecraft Thermal Control 5 THERMAL ANALYSIS PROGRAMS FOURIER S LAW OF HEAT CONDUCTION FIRST LAW OF THERMODYNAMICS RAD PROGS. SSPTA, RADFAC, NEVADA, TRAYSIS GENERAL 3D HEAT CONDUCTION EQUATION ADDITION OF RADIATION ETC. COMPUTER SOLUTION OF DIFFERENCE EQUATION CONVERSION OF EQUATION TO FINITE DIFFERENCE GENERAL FINITE DIFFERENCE HEAT FLOW EQUATION COMMERCIAL PROGRAMS SINDA, TAK, ESATAN, PC3D, ITAS Boundary conditions (external heat inputs, internal power), TAM

8 Spacecraft Thermal Control 6 RADIATION RADIATION IS THE ONLY MEANS OF ENERGY TRANSFER TO AND FROM THE SPACECRAFT IN SPACE IT IS ALSO AN IMPORTANT MEANS OF TRANSFER WITHIN THE SPACECRAFT WE WILL COVER THE FOLLOWING IN THIS SECTION: BLACKBODY RADIATION REFLECTION AND EMISSION RADIATION HEAT TRANSFER BETWEEN TWO BLACK BODIES RADIATION TRANSFER BETWEEN TWO REAL BODIES SOLAR SPECTRUM SOLAR ABSORPTANCE AND IR EMITTANCE MEASUREMENTS

9 Spacecraft Thermal Control 7 THERMAL DESIGN 1 THERMAL DESIGN CONSISTS OF MAKING CHOICES FOR: RADIATOR LOCATIONS THERMAL CONTROL SURFACES FOR THE RADIATORS THERMAL CONTROL SURFACES FOR OTHER EXTERNAL AND INTERNAL COMPONENTS INSULATION LOCATIONS AND TYPE THERMAL DEVICES SUCH AS: LOUVERS HEAT PIPES HEATERS, THERMOSTATIC AND COMMANDABLE PHASE CHANGE PACKAGES THERMOELECTRIC COOLERS RADIOACTIVE HEAT SOURCES CRYOGENIC COOLERS OR DEWARS STRUCTURE AND THERMAL DOUBLERS

10 Spacecraft Thermal Control AVAILABILITY OF COATINGS Black Ni, Cr, Cu Black paint Solar Absorptance, α Au Aluminum paint Kapton Al White paint 0.2 Polished metals FEP Teflon, with Ag, Al Ag OSR Emittance, Figure 7-7 Solar Absorptance versus Emittance for Typical Materials ε

11 Spacecraft Thermal Control 9 HEAT PIPES SIMPLE PASSIVE HEAT PIPE Q PRESSURE VESSEL, (PIPE) WORKING FLUID WICK Q EVAPORATOR CONDENSER PIPE AND WICK - ALUMINUM FLUID - FREON EFFECTIVE THERMAL CONDUCTIVITY MANY TIMES HIGHER THAN SOLID CONDUCTORS RELIABLE IF PROPERLY CONSTRUCTED LIGHT WEIGHT MODERATE IN COST FOR STANDARD DESIGNS APPLICATIONS MUST CONSIDER TESTING IN THE DESIGN PROCESS (AT 1G THEY MUST BE NEARLY HORIZONTAL TO OPERATE)

12 T-Test Boundary Temp. Fixed at calculated prediction Spacecraft Thermal Control 10 Q-test vs. T-test Q -Test Boundary Temp. fixed by equilibrium energy flow between simulated environment and radiation to cold walls S/C Int. Pwr. Radiation to Cold walls S/C Int. Pwr. Radiation to Cold walls Controlling Heat input Tests only the internal model which is correlated by comparison of test result and test simulation Simulated space environmental Heat input The accuracy of this technique is limited only by the ability to simulate the space environment and the correct orbital configuration

13 Boost Your Skills with On-Site Courses Tailored to Your Needs The Applied Technology Institute specializes in training programs for technical professionals. Our courses keep you current in the state-of-the-art technology that is essential to keep your company on the cutting edge in today s highly competitive marketplace. For 20 years, we have earned the trust of training departments nationwide, and have presented on-site training at the major Navy, Air Force and NASA centers, and for a large number of contractors. Our training increases effectiveness and productivity. Learn from the proven best. ATI s on-site courses offer these cost-effective advantages: You design, control, and schedule the course. Since the program involves only your personnel, confidentiality is maintained. You can freely discuss company issues and programs. Classified programs can also be arranged. Your employees may attend all or only the most relevant part of the course. Our instructors are the best in the business, averaging 25 to 35 years of practical, realworld experience. Carefully selected for both technical expertise and teaching ability, they provide information that is practical and ready to use immediately. Our on-site programs can save your facility 30% to 50%, plus additional savings by eliminating employee travel time and expenses. The ATI Satisfaction Guarantee: You must be completely satisfied with our program. We suggest you look at ATI course descriptions in this catalog and on the ATI website. Visit and bookmark ATI s website at for descriptions of all of our courses in these areas: Communications & Computer Programming Radar/EW/Combat Systems Signal Processing & Information Technology Sonar & Acoustic Engineering Spacecraft & Satellite Engineering I suggest that you read through these course descriptions and then call me personally, Jim Jenkins, at (410) , and I ll explain what we can do for you, what it will cost, and what you can expect in results and future capabilities. Our training helps you and your organization remain competitive in this changing world. Register online at or call ATI at or