The Surveyor thermal switch
Surveyor thermal switch for temperature control to assure spacecraft components performance during temperature extremes on lunar surface
Deal, T. E.↗
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The 1973 Mariner mission to Venus and Mercury. II
The heart of the spacecraft downlink is the flight data subsystem (FDS). The FDS combines the functions of science and engineering measurement control. The FDS can generate six principal telemetry formats, each of which may be transmitted directly to earth. Spacecraft engineering subsystems are considered, giving attention to the power subsystem, the attitude control subsystem, the propulsion subsystem, devices for temperature control, and the tracking subsystem. The mission operations system is also discussed together with the flight plan.
Hooke, A. J.↗
The heat pipe thermal canister
The thermal canister represents a new approach to instrument thermal control for Shuttle experiments which require tight temperature control. The canister substitutes a known, benign thermal environment for the variable and uncertain environment of space, the space environment being neutralized by a system of feedback controlled variable conductance heat pipes. A proto-flight unit has been fabricated and this paper describes the acceptance thermal vacuum test results of the thermal canister experiment which will fly on an early Space Shuttle flight.
Harwell, W.↗
Optimal control of thermally coupled Navier Stokes equations
The optimal boundary temperature control of the stationary thermally coupled incompressible Navier-Stokes equation is considered. Well-posedness and existence of the optimal control and a necessary optimality condition are obtained. Optimization algorithms based on the augmented Lagrangian method with second order update are discussed. A test example motivated by control of transport process in the high pressure vapor transport (HVPT) reactor is presented to demonstrate the applicability of our theoretical results and proposed algorithm.
Ito, Kazufumi↗
Highlights of the Zeno Results from the USMP-2 Mission
The Zeno instrument, a High-precision, light-scattering spectrometer, was built to measure the decay rates of density fluctuations in xenon near its liquid-vapor critical point in the low-gravity environment of the U.S. Space Shuttle. Eliminating the severe density gradients created in a critical fluid by Earth's gravity, we were able to make measurements to within 100 microKelvin of the critical point. The instrument flew for fourteen days in March, 1994 on the Space Shuttle Columbia, STS-62 flight, as part of the very successful USMP-2 payload. We describe the instrument and document its performance on orbit, showing that it comfortably reached the desired 3 microKelvin temperature control of the sample. Locating the critical temperature of the sample on orbit was a scientific challenge; we discuss the advantages and short-comings of the two techniques we used. Finally we discuss problems encountered with making measurements of the turbidity of the sample, and close with the results of the measurement of the decay rates of the critical-point fluctuations.
Gammon, Robert W.↗
Emulsion Chamber Technology Experiment (ECT)
The experimental objective of Emulsion Chamber Technology (ECT) was to develop space-borne emulsion chamber technology so that cosmic rays and nuclear interactions may subsequently be studied at extremely high energies with long exposures in space. A small emulsion chamber was built and flown on flight STS-62 of the Columbia in March 1994. Analysis of the several hundred layers of radiation-sensitive material has shown excellent post-flight condition and suitability for cosmic ray physics analysis at much longer exposures. Temperature control of the stack was 20 +/-1 C throughout the active control period and no significant deviations of temperature or pressure in the chamber were observed over the entire mission operations period. The unfortunate flight attitude of the orbiter (almost 90% Earth viewing) prevented any significant number of heavy particles (Z greater than or equal to 10) reaching the stack and the inverted flow of shower particles in the calorimeter has not allowed evaluation of absolute primary cosmic ray-detection efficiency nor of the practical time limits of useful exposure of these calorimeters in space to the level of detail originally planned. Nevertheless, analysis of the observed backgrounds and quality of the processed photographic and plastic materials after the flight show that productive exposures of emulsion chambers are feasible in low orbit for periods of up to one year or longer. The engineering approaches taken in the ECT program were proven effective and no major environmental obstacles to prolonged flight are evident.
Gregory, John C.↗
Cryogenic Chamber for Servo-Hydraulic Materials Testing
A compact cryogenic test chamber can be cooled to approximately 5 to 6 Kelvin for materials testing. The system includes a temperature controller and multiple sensors to measure specimen temperature at different locations. The testing chamber provides a fast and easy method to perform materials testing at lower than liquid nitrogen temperature (77 K). The purpose of the chamber is to cool a composite lap shear specimen to approximately 20 K so that tensile test force and displacement data may be acquired at this cryogenic temperature range.
Francis, John J.↗
Development of Two Color Fluorescent Imager and Integrated Fluidic System for Nanosatellite Biology Applications
Nanosatellites offer frequent, low-cost space access as secondary payloads on launches of larger conventional satellites. We summarize the payload science and technology of the Microsatellite in-situ Space Technologies (MisST) nanosatellite for conducting automated biological experiments. The payload (two fused 10-cm cubes) includes 1) an integrated fluidics system that maintains organism viability and supports growth and 2) a fixed-focus imager with fluorescence and scattered-light imaging capabilities. The payload monitors temperature, pressure and relative humidity, and actively controls temperature. C. elegans (nematode, 50 m diameter x 1 mm long) was selected as a model organism due to previous space science experience, its completely sequenced genome, size, hardiness, and the variety of strains available. Three strains were chosen: two green GFP-tagged strains and one red tdTomato-tagged strain that label intestinal, nerve, and pharyngeal cells, respectively. The integrated fluidics system includes bioanalytical and reservoir modules. The former consists of four 150 L culture wells and a 4x5 mm imaging zone the latter includes two 8 mL fluid reservoirs for reagent and waste storage. The fluidic system is fabricated using multilayer polymer rapid prototyping: laser cutting, precision machining, die cutting, and pressure-sensitive adhesives it also includes eight solenoid-operated valves and one mini peristaltic pump. Young larval-state (L2) nematodes are loaded in C. elegans Maintenance Media (CeMM) in the bioanalytical module during pre-launch assembly. By the time orbit is established, the worms have grown to sufficient density to be imaged and are fed fresh CeMM. The strains are pumped sequentially into the imaging area, imaged, then pumped into waste. Reagent storage utilizes polymer bags under slight pressure to prevent bubble formation in wells or channels. The optical system images green and red fluorescence bands by excitation with blue (473 nm peak) and amber (587 nm peak) LEDs it achieves 8 m lateral resolution using a CMOS imaging chip (as configured for serial data speeds) or 4 m resolution using USB imaging chips. The imager consists of a modified commercial off-the-shelf CMOS chip camera, amber, blue and white LEDs, as well as a relay lens and dual-band filters to obviate moving parts while supporting both fluorescence wavelengths.
Wu, Diana Terri↗
RST Optical Telescope Build Progress
The Nancy Grace Roman Space Telescope (RST) is a Hubble-size telescope with a large field of view for large surveys of the sky, cold temperatures for enabling near infrared imaging, and controlled temperature stability for long exposures and coronagraphy. The OTA includes the primary mirror, secondary mirror, and aft optics for inserting light into the Wide Field Instrument and the Coronagraph Instrument. The testing of the optical assemblies and structures are nearly complete and ready for telescope integration. Pictures and descriptions of the assemblies will be provided, followed by performance results achieved at these level of assemblies.
Tony Whitman↗
Roman Optical Telescope Assembly (OTA) Build and Integration Progress
The Nancy Grace Roman Space Telescope (RST) is a Hubble-class telescope with a large field of view for large surveys of the sky, cold temperatures for enabling near infrared imaging, and controlled temperature stability for long exposures and coronagraphy. The OTA includes the primary mirror, secondary mirror, and aft optics for guiding light into the Wide Field Instrument and the Coronagraph Instrument. The testing of the optical assemblies and structures are nearly complete in preparation for telescope integration. Pictures and descriptions of the assemblies are provided, followed by performance results measured at these level of assemblies. The assemblies are nearly complete as they are tested through thermal cycling to cold temperatures for infrared operation, mechanical strength and vibration, and optically testing. Optical surface figure error results are shown for all the optical surfaces.
RST↗
Control and measurement of temperatures of Mariner IV.
Control and measurement of temperatures of Mariner IV
SPACECRAFT CONTROL↗
OSS-1/contamination monitor
A 20-cm high, 18-cm wide, and 30-cm long (8x7x12 inch) box weighing about 7 kg (15 lbs) and consuming about 7 watts of power was carried on the OSS-1 pallet to monitor the mass build-up or accretion of condensible, volatile materials on surfaces in the shuttle bay during all phases of ascent, on-orbit, and descent. Passively thermally controlled, the box holds two witness samples and four actively temperature controlled quartz crystal microbalances (TQCM) whose temperature can vary from -60 C to +80 C. Graphs show the accretion indicated by the TQCM during the launch and early orbital phase. Conditions during tail to the Sun, nose to the Sun, and bay to the Sun attitudes of the shuttle during STS-3 are reflected in temperatures indicated by the OSS-1 thermistor. These temperatures influence outgassing rates of various materials as well as measurements made by the contamination monitor package. The parameters that bear on TQCM measurements data are shown in graphs and discussed.
Kruger, R.↗
Capillary Limit of a Miniature Loop Heat Pipe with Multiple Evaporators and Multiple Condensers
An experimental investigation of a miniature loop heat pipe with multiple evaporators and multiple condensers were conducted in order to evaluate its capillary limit. The experimental tests were conducted by varying heat load to one or both evaporators, with and without active temperature control of compensation chamber (CC) using the thermoelectric devices, and variable tilts between the evaporators and the CCs. The physical process of the loop and thermal conductance of the heat leak from evaporator to (CC) were discussed based on the test results. The difference of the temperature profiles between with and without active control of CC temperature was evaluated. The effect of the gravity on capillary limit and CC temperature was also evaluated by comparing the test result in horizontal position with that in vertical position. The loop recovery after capillary limit was exceeded was also described.
Ku, Jentung↗
Construction and testing of a gas-loaded, passive-control, variable-conductance heat pipe
A methanol heat pipe using nitrogen gas for temperature control has been constructed and tested. The system was run over a power ratio of 15 (2 to 30 watts) with the heat source near ambient temperature and with the heat sink at a nominal value of 32 F. Control was obtained with a metal bellows gas reservoir which was actuated by an internal liquid-filled bellows. The liquid bellows was pressurized by expanding liquid methanol which was contained in an auxiliary reservoir in the evaporator heater block. It was demonstrated that the temperature variation of the heat source was reduced from 36 F for the heat pipe with no control to 7 F with the actuated bellows control.
Depew, C. A.↗
Advanced Thermal Control Flight Experiment.
The advanced Thermal Control Flight Experiment on the Applications Technology Satellite (ATS-F) will evaluate, for the first time in a space environment, the performance of a feedback-controlled variable conductance heat pipe and a heat pipe thermal diode. In addition, the temperature control aspects of a phase-change material (PCM) will be demonstrated. The methanol/stainless steel feedback-controlled heat pipe uses helium control gas that is stored in a wicked reservoir. This reservoir is electrically heated through a solid state controller that senses the temperature of the heat source directly. The ammonia/stainless steel diode heat pipe uses excess liquid to block heat transfer in the reverse direction. The PCM is octadecane. Design tradeoffs, fabrication problems, and performance during qualification and flight acceptance tests are discussed.
Kirkpatrick, J. P.↗
Temperature Compensated Sapphire Resonator for Ultrastable Oscillator Operating at Temperatures Near 77 Deg Kelvin
A sapphire resonator for an ultrastable oscillator capable of substantial performance improvements over the best available crystal quartz oscillators in a compact cryogenic package is based on a compensation mechanism enabled by the difference between copper and sapphire thermal expansion coefficients for so tuning the resonator as to cancel the temperature variation of the sapphire's dielectric constant. The sapphire resonator consists of a sapphire ring separated into two parts with webs on the outer end of each to form two re-entrant parts which are separated by a copper post. The re-entrant parts are bonded to the post by indium solder for good thermal conductivity between parts of that subassembly which is supported on the base plate of a closed copper cylinder (rf shielding casing) by a thin stainless steel cylinder. A unit for temperature control is placed in the stainless steel cylinder and is connected to the subassembly of re-entrant parts and copper post by a layer of indium for good thermal conduction. In normal use, the rf shielding casing is placed in a vacuum tank which is in turn placed in a thermos flask of liquid nitrogen. The temperature regulator is controlled from outside the thermos flask to a temperature in a range of about 40K to 150K, such as 87K for the WGH-811, mode of resonance in response to microwave energy inserted into the rf shielding casing through a port from an outside source.
Dick, G. John↗
Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity
The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.
Marangoni and Natural Convection↗
Thermal control characteristics of a diffuse bladed, specular base louver system.
Spacecraft temperature control louver system using diffuse metallic blades and specular base reflection
Parmer, J. F.↗