Steady-State Thermal Design of Space Radiators
Steady state thermal design of space radiators consisting of flat panel containing parallel single pass tubes
Chapman, A. J.↗
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Tethered satellite thermal design and test
The Tethered Satellite System (TSS) is the first Shuttle Orbiter mission that investigates electrodynamic phenomenon of a 20 km conductive tether, in space. The TSS Mission is planned for January 1992. The 'Deployer' that provides the mechanisms that control a tethered satellite is mounted on a Spacelab Pallet. The Deployer thermal design uses Multilayer Insulation (MLI), heaters, and the Spacelab payload freon loop. The pallet and Deployer are isolated from the space thermal environment with MLI that forms an enclosure that is a unique part of the thermal design. This paper describes the TSS thermal design, presents the analysis approach, and details the Deployer thermal balance test.
Chapter, John J.↗
Thermal design support for the Explorer gamma ray experiment telescope
The results of a thermal design definition study for the GSFC Explorer Gamma Ray Experiment Telescope (EGRET) were documented. A thermal computer model of EGRET with 241 nodes was developed and used to analyze the thermal performance of the experiment for a range of orbits, payload orientations and internal power dissipations. The recommended thermal design utilizes a small radiator with an area of 1.78 square foot on the anti-sun side of the mission adaptor and circumferential heat pipes on the interior of the same adaptor to transfer heat from the electronics compartments to the single radiator. Fifty watts of thermostatically controlled heater power are used to control the temperature level to 10 C + or - 20 C inside the insulated dome structure.
Almgren, D. W.↗
Conceptual thermal design and analysis of a far-infrared/mid-infrared remote sensing instrument
This paper presents the conceptual thermal design and analysis results for the Spectroscopy of the Atmosphere using Far-Infrared Emission (SAFIRE) instrument. SAFIRE has been proposed for Mission to Planet Earth to study ozone chemistry in the middle atmosphere using remote sensing of the atmosphere in the far-infrared (21-87 microns) and mid-infrared (9-16 microns) spectra. SAFIRE requires that far-IR detectors be cooled to 3-4 K and mid-IR detectors to 80 K for the expected mission lifetime of five years. A superfluid helium dewar and Stirling-cycle cryocoolers provide the cryogenic temperatures required by the infrared detectors. The proposed instrument thermal design uses passive thermal control techniques to reject 465 watts of waste heat from the instrument.
Roettker, William A.↗
Voyager spacecraft thermal design problems.
Voyager spacecraft thermal control design noting heat rejection louvers and multilayer insulation
Lankton, C.↗
A conceptual thermal design study of an electronically scanned thinned array radiometer
This report describes conceptual thermal design study for an Electronically Scanned Thinned Array Radiometer (ESTAR). ESTAR is an instrument concept for the measurement of soil moisture from space using synthetic aperture radiometry. The thermal design goal is to minimize the orbital temperature variation of the radiometer receivers using established materials and techniques. Two design approaches have been investigated; the first uses the waveguide as a heat sink, and the second uses a nadir facing radiator on the receiver assembly. The second approach minimizes the receiver's impact on the waveguide temperatures. Predicted temperatures for all receivers are presented for the two cases indicating the transient thermal environments the receivers would experience during an orbit. In addition, the effects of the receiver heat dissipation on the waveguide temperatures are shown.
Gould, D. C.↗
Assessment of the Mars Helicopter Thermal Design Sensitivities Using the Veritrek Software
The Mars Helicopter will be a technology demonstration conducted during the Mars 2020 mission. The primary mission objective is to achieve several 90-second flights and capture visible light images via forward and nadir mounted cameras. These flights could possibly provide reconnaissance data for sampling site selection for other Mars surface missions. The helicopter is powered by a solar array, which stores energy in secondary batteries for flight operations, imaging, communications, and survival heating. The helicopter thermal design is driven by minimizing survival heater energy while maintaining compliance with allowable flight temperatures in a variable thermal environment. Due to the small size of the helicopter and its complex geometries, along with the fact that it operates with very low power and small margins, additional care had to be paid while planning thermal tests and designing the thermal system. A Thermal Desktop® model has been developed to predict the thermal system’s performance. A reduced-order model (ROM) created with the Veritrek software has been utilized to explore the sensitivities of the thermal system’s drivers, such as electronics dissipations, gas gaps, heat transfer coefficients, etc., as well as to assess and verify the final thermal design. This paper presents the performance of the Veritrek software products and the details of the ROM creation process. The results produced by Veritrek were utilized to study the effect of the major thermal design drivers and Mars environment on the Mars Helicopter in as little as 10 days, an effort that would have taken over 4 months using traditional thermal analysis techniques.
Hengeveld, Derek W.↗
Thermal design of the Cosmic Background Explorer cryogenic optical assembly
The Cosmic Background Explorer (COBE) is a satellite which is designed to study the 3-K cosmic background radiation. Two cryogenic instruments and a common support structure comprise the Cryogenic Optical Assembly (COA). In order to make definitive measurements of the low-energy FIR radiation, the temperature of the COA must be maintained below 3 K. Temperature control of the COA elements is achieved by the use of a superfluid helium dewar. The thermal design also minimizes power dissipation, transient operational effects, and thermal gradients within the COA. This is accomplished by isolating selected components and heat-sinking others to various locations on the cryogen tank. The thermal design was developed primarily through analysis. Analytical models were created to perform parametric design studies. Ground testing was performed to correlate the thermal models and validate the thermal design. Both test and flight data confirmed that all design requirements were either met or exceeded.
Mosier, Carol L.↗
Applications of high thermal conductivity composites to electronics and spacecraft thermal design
Recently, high thermal conductivity graphite fiber-reinforced metal matrix composites (MMCs) have become available that can save weight over present methods of heat conduction. Another significant advantage is that these materials can be used without the plumbing and testing complexities that accompany the use of liquid heat pipes. A spinoff of this research was the development of other MMCs as electronic device heat sinks. These use particulates rather than fibers and are formulated to match the coefficient of thermal expansion of electronic substrates in order to alleviate thermally induced stresses. The development of both types of these materials as viable weight-saving substitutes for the traditional methods of thermal control for electronics packaging and also for spacecraft thermal control applications are the subjects of this report.
Sharp, G. Richard↗
Applications of high thermal conductivity composites to electronics and spacecraft thermal design
Recently, high thermal conductivity continuous graphite fiber reinforced metal matrix composites (MMC's) have become available that can save much weight over present methods of heat conduction. These materials have two or three times higher thermal conductivity in the fiber direction than the pure metals when compared on a thermal conductivity to weight basis. Use of these materials for heat conduction purposes can result in weight savings of from 50 to 70 percent over structural aluminum. Another significant advantage is that these materials can be used without the plumbing and testing complexities that accompany the use of liquid heat pipes. A spinoff of this research was the development of other MMC's as electronic device heat sinks. These use particulates rather than fibers and are formulated to match the coefficient of thermal expansion of electronic substrates in order to alleviate thermally induced stresses. The development of both types of these materials as viable weight saving substitutes for traditional methods of thermal control for electronics packaging and also for spacecraft thermal control applications are the subject of this report.
Sharp, G. Richard↗
Thermal design optimization of a segmented GFRP primary reflector for a submillimeter telescope
Results are presented of a thermal design optimization study of the segmented GFRP primary reflector of the earth-orbiting Submillimeter Imager and Line Survey telescope. The paper examines the thermal requirements of the primary reflector and the thermal environment of the telescope and describes the thermal design of the primary reflector. Particular attention is given to the geometric math model and the thermal math model of the telescope. A summary for the steady-state thermal performance of the optimized design is presented, showing that the optimized design has reduced, by an order of magnitude, structural spatial temperature gradients, which were earlier shown to be the most significant obstacle in maintaining the required telescope figure accuracy.
Tsuyuki, Glenn T.↗
Thermal design, analysis and testing of the Halogen Occultation Experiment
This paper briefly introduces the Halogen Occultation Experiment (HALOE) and describes the thermal requirements in some detail. The thermal design of the HALOE is described, together with the design process and the analytical techniques used to arrive at this design. The flight hardware has undergone environmental testing in a thermal vacuum chamber to validate the thermal design. The HALOE is a unique problem in thermal control due to its variable solar loading, its extremely sensitive optical components and the high degree of pointing accuracy required. This paper describes the flight hardware, the design process and its verification.
Foss, Richard A.↗
Thermal Design of Astrobee Perching Arm
This paper presents the thermal design of actuators in the perching arm of Astrobee robot that will operate inside the International Space Station (ISS) in starting 2019. Since the crew's safety is of the utmost importance on the ISS, all materials used in the Astrobee robot should meet the touch temperature requirements according to the ISS safety standards to protect crew from skin burns. The Astrobee perching arm consists of 2-DOF arm servo motors and 1-DOF gripper DC motor, which are capable of overheating when stalled, particularly given the lack of gravity-driven thermal convection in the ISS zero-gee environment. Thermal properties of two types of actuators are verified by monitoring the touch temperature in worst-case operations with no thermal protection. Then, the proper thermal protection designs have been conducted and installed to guarantee the safety in all conditions.
Park, In-Won↗
Thermal Design of Astrobee Perching Arm
This paper presents the thermal design of actuators in the perching arm of Astrobee robot that will operate inside the International Space Station (ISS) starting in 2019. Since the crew's safety is of the utmost importance on the ISS, all materials used in the Astrobee robot should meet the touch temperature requirements according to the ISS safety standards to protect crew from skin burns by controlling the exposure temperature. The Astrobee perching arm consists of 2-DOF (Degrees-of-Freedom)- arm servo motors and 1-DOF gripper DC motor, which are capable of overheating in the stalled condition. Thermal properties of two types of actuators are verified by monitoring the touch temperature in worst-case operations with no thermal protection. Then, the proper thermal protection designs have been conducted and installed to guarantee the safety in all conditions.
Park, In-Won↗
An assessment of thermal design procedures for Shuttle payloads
A review of the thermal design options for unmanned Shuttle payloads is presented. Because many future Shuttle payloads will have budgets and less time available for the definition of their thermal subsystems, simplified design procedures will be the most cost-effective. The thermal interface between an individual payload and the Orbiter is discussed. A simplified, modular thermal control system that will reduce the cost of providing thermal protection by minimizing both the initial procurement cost of any specialized hardware and the need for a detailed thermal interface analysis is described.
Almgren, D. W.↗
Tethered Satellite System Tip Canister - Thermal design and test
The Tethered Satellite System (TSS) is scheduled for launch, on STS-46 in mid-1992. The major mission objective is to investigate electrodynamic phenomena associated with long electrically conductive tether, in the earth orbital environment. A spherical Satellite (1.6-m diameter), remains connected to the Orbiter throughout TSS-1 mission by a conductive tether. The Satellite operates at up to 20 km above the Orbiter during the TSS mission. The Tip Canister (TPC), that is mounted on the end of a 12-m retractable boom, contains mechanisms that control and monitor tether movement. The TPC is an independent thermal system from the base 'Deployer/Spacelab Pallet'. This paper presents the TPC thermal design verification approach that includes a description of thermal design and thermal balance testing. Flight TPC temperature predictions are also presented.
Chapter, John J.↗
Thermal design of the Galileo bus and Retro Propulsion Module
The Galileo spacecraft (S/C) consists of an Orbiter and Probe which have instruments to investigate the chemical composition and physical state of Jupiter's atmosphere, the Jovian satellites and the structure and physical dynamics of the Jovian magnetosphere. Galileo was at the Kennedy Space Center (KSC) preparing for a May 1986 launch at the time of the Challenger accident. The delay and an incraease in mission time has decreased the Radioisotope Thermoelectric Generator power output significantly. A change to the Inertial Upper Stage from the more powerful Centaur G-Prime has resulted in a trajectory that requires gravity assists once by Venus and twice by earth. The resulting peak solar intensity of this roundabout trajectory is more than twice the previous design value for the direct trajectory. Galileo was returned to the Jet Propulsion Laboratory (JPL) from KSC in February 1987 to begin the rework of the S/C thermal design. Verification of the thermal redesign was completed in the JPL 25' space simulator in August and November of 1988. This paper summarizes the thermal design and redesign of the Bus and Retro Propulsion Model.
Avila, A.↗
Thermal design of the ACCESS erectable space truss
Thermal design requirements for the erectable truss beam to be assembled in-orbit during extra-vehicular activity as part of the ACCESS experiment to take place in 1985-1986 are formulated and assessed. The coatings, insulation, and materials chosen for the structural elements of the beam are detailed. A combined radiation and conduction thermal model reveals that worst-case thermal gradients within the ACCESS structure over plane-to-sun angles of 0 to 80 deg will be less than 29 F, which is within the allowable limit of 50 F. The individual strut insulation concept using aluminized Kapton is shown to offer significant advantages over white paint or a chromic acid anodized surface for controlling the thermal response.
Bradley, O. H., Jr.↗