Design and Manufacturing of a Technology Demonstration Model for a Heat Rejection System Dedicated to Advanced Spacecraft and Payload Thermal Control

1983 ◽  
Author(s):  
Jean Pierre Bouchez ◽  
Luigi Bussolino
Keyword(s):  
Thermal Control ◽  
Heat Rejection ◽  
Design And Manufacturing ◽  
Technology Demonstration

scholarly journals Prospects for Implementing Variable Emittance Thermal Control of Space Suits on the Martian Surface

2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Christopher J. Massina ◽  
David M. Klaus
Keyword(s):  
Environmental Parameters ◽  
Landing Site ◽  
Thermal Control ◽  
Control Mechanisms ◽  
Martian Surface ◽  
Solar Absorption ◽  
Heat Rejection ◽  
Extravehicular Activity ◽  
Space Suits ◽  
Rejection Mechanism

Extravehicular activity (EVA) will play an important role as humans begin exploring Mars, which, in turn, will drive the need for new enabling technologies. For example, space suit heat rejection is currently achieved through the sublimation of ice water to the vacuum of space, a mechanism widely regarded as not feasible for use in Martian environment pressure ranges. As such, new, more robust thermal control mechanisms are needed for use under these conditions. Here, we evaluate the potential of utilizing a full suit, variable emittance radiator as the primary heat rejection mechanism during Martian surface EVAs. Diurnal and seasonal environment variations are considered for a latitude 27.5°S Martian surface exploration site. Surface environmental parameters were generated using the same methods used in the initial selection of the Mars Science Laboratory's initial landing site. This evaluation provides theoretical emittance setting requirements to evaluate the potential of the system's performance in a Mars environment. Parametric variations include metabolic rate, wind speed, radiator solar absorption, and total radiator area. The results showed that this thermal control architecture is capable of dissipating a standard nominal EVA metabolic load of 300 W in all the conditions with the exception of summer noon hours, where a supplemental heat rejection mechanism with a 250 W capacity must be included. These results can be used to identify when conditions are most favorable for conducting EVAs. The full suit, variable emittance radiator architecture provides a viable means of EVA thermal control on the Martian surface.

Defining a Discretized Space Suit Surface Radiator With Variable Emissivity Properties

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Christopher J. Massina ◽  
David M. Klaus
Keyword(s):  
Heat Flux ◽  
Constant Temperature ◽  
Thermal Control ◽  
Constant Heat Flux ◽  
Order Estimate ◽  
Space Suit ◽  
Constant Heat ◽  
Load Range ◽  
Heat Rejection ◽  
Integration Architecture

Heat rejection for space suit thermal control is typically achieved by sublimating water ice to vacuum. Converting the majority of a space suit's surface area into a radiator may offer an alternative means of heat rejection, thus reducing the undesirable loss of water mass to space. In this work, variable infrared (IR) emissivity electrochromic materials are considered and analyzed as a mechanism to actively modulate radiative heat rejection in the proposed full suit radiator architecture. A simplified suit geometry and lunar pole thermal environment is used to provide a first-order estimate of electrochromic performance requirements, including number of individually controllable pixels and the emissivity variation that they must be able to achieve to enable this application. In addition to several implementation considerations, two fundamental integration architecture options are presented—constant temperature and constant heat flux. With constant temperature integration, up to 48 individual pixels with an achievable emissivity range of 0.169–0.495 could be used to reject a metabolic load range of 100 W–500 W. Alternatively, with constant heat flux integration, approximately 400 pixels with an achievable emissivity range of 0.122–0.967 are required to reject the same load range in an identical external environment. Overall, the use of variable emissivity electrochromics in this capacity is shown to offer a potentially feasible solution to approach zero consumable loss thermal control in space suits.

Application of Affordable Composite Materials and Processes on UCAV (Extended Abstract)

2001 ◽  
Author(s):  
Steve J. Schwedt
Keyword(s):  
Composite Materials ◽  
Air Force ◽  
Flight Test ◽  
Advanced Technology ◽  
Demonstration Program ◽  
Air Vehicle ◽  
Design And Manufacturing ◽  
Technology Demonstration ◽  
Air Vehicles

Abstract The Unmanned Combat Air Vehicle (UCAV) program is an Advanced Technology Demonstration Program funded by DARPA and the Air Force. As a part of the program two demonstration air vehicles were fabricated and assembled for flight test and for demonstrating the affordability of UCAVs. Using advanced design and manufacturing toolsets, the first vehicle, 27 feet long with a 34-foot wingspan, was designed and delivered in 18 months. In addition, unique fabrication, tooling, and assembly techniques were used to produce these vehicles. This presentation will discuss the techniques used that led to the success of the program.

scholarly journals РАЗРАБОТКА КОНЦЕПЦИИ ДВУХФАЗНОЙ СИСТЕМЫ ТЕПЛООТВОДА СПУТНИКА

2021 ◽  
pp. 31-46
Author(s):  
Рустем Юсуфович Турна
Keyword(s):  
Control System ◽  
Power Systems ◽  
Thermal Control ◽  
Practical Implementation ◽  
Space Technology ◽  
Two Phase ◽  
Heat Rejection ◽  
Design And Optimization ◽  
Thermal Control System ◽  
Hydraulic Network

For spacecraft (SC) with power unit capacity more than 4 ... 6 kW promising construction of thermal control system (TCS) based on two-phase mechanically pumped loops (2PMPL). The development of 2PMPL has been carried out quite intensively since the early '80s. However, so far there are no examples of practical implementation of such high-power systems. One of the main reasons mentioned is the novelty of the system, and insufficient study of its operation in space conditions, which adds risks. The most important component of such systems is a heat rejection subsystem (HRS), whose task is to reject heat from the coolant and radiate it into space. In its turn, HRS is also a system, the design of which requires using a system approach, considering various aspects of its operation. HRS includes a heat-hydraulic network and a radiation heat exchanger (RHE). The key elements of the HRS are condensers (CC), quite new devices for space technology. This paper presents an algorithm for the design and optimization of the heat rejection subsystem (HRS) of a satellite two-phase thermal control system. The methodology of engineering synthesis of complex technical systems and informal procedures for multi-criteria optimization of elements and subsystems at various stages of HRS design is repeatedly used. t is shown that optimization should be carried out both at the level of elements and subsystems, and at the level of the whole thermal control system. As a result of the study, the HRS design is proposed, which uses condensers in the form of smooth steel tubes of constant cross-section and their series-parallel connection scheme in the hydraulic network. Main advantages of the design: traditional for single-phase loops elements are used; operation of elements and subsystems in zero gravity conditions is predictable and allows complete testing on the ground without mandatory flight experiment; the system is operable at high saturation pressures (temperatures) (on ammonia - up to 85℃).

Development and Experimental Demonstration of a Shape Memory Alloy-Based Adaptive Two-Phase Radiator for Space Applications

2020 ◽  
Author(s):  
Jared Lilly ◽  
Bethany Hansen ◽  
Ryan Lotz ◽  
Darren Hartl ◽  
Thomas Cognata ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Single Phase ◽  
Thermal Control ◽  
Working Fluid ◽  
Two Phase ◽  
Space Applications ◽  
Regenerative Heat ◽  
Heat Rejection ◽  
Wide Range

Abstract Future space exploration, such as the Artemis program, journeys to Mars, and future lander missions will require thermal control systems (TCSs) with the ability to adapt to a wide range of thermal loads due to vastly fluctuating external temperatures. Current TCSs employ radiators that can achieve a turndown ratio (defined as the ratio of the maximum to minimum heat rejection rates) of 12:1 by utilizing regenerative heat exchangers and a two-fluid-loop system, both of which are heavy and complex. However, future missions will demand radiators that can provide turndown ratios of 12:1 while remaining light, functionally passive, and simply designed. Previous work has investigated using shape memory alloy (SMA) components in single phase radiator prototypes to achieve efficient heat rejection. Preliminary analysis shows that SMA-based radiators can enable turndown ratios as high as 37:1. In this paper, the design, fabrication, and testing of an SMA torque tube driven radiator prototype is discussed. The SMA torque tube is attached to a heat rejecting panel that resembles flat radiator panels currently installed on the International Space Station. As the temperature of the working fluid in the TCS increases, the SMA torque tube actuates and rotates the panel, allowing for more radiative heat rejection to occur. This new design matures the concept past a previous prototype that merely demonstrated actuation under single-phase (e.g., liquid water) flow. The current radiator prototype has been designed to function not only with closed-loop, single-phase fluid flow, but also in conjunction with a two-phase TCS and even as a heat pipe. Both approaches take advantage of phase transformation of the working fluid to improve overall TCS efficiency and decrease complexity. During testing, a heated two-phase working fluid was circulated through the system, resulting in a maximum angular actuation of 67 degrees, thus demonstrating two-phase operation for the first time. These results give confidence that an SMA torque tube-driven radiator can outperform current radiators as development continues.

Towards High Turndown Ratio Shape Memory Alloy-Driven Morphing Radiators

2018 ◽  
Author(s):  
Patrick Walgren ◽  
Othmane Benafan ◽  
Lisa Erickson ◽  
Darren Hartl
Keyword(s):  
Shape Memory ◽  
Control Systems ◽  
Mechanical Response ◽  
Thermal Environment ◽  
Shape Change ◽  
Rejection Rate ◽  
Thermal Control ◽  
Design Tool ◽  
Sensors And Actuators ◽  
Heat Rejection

Future manned space missions will require thermal control systems that can adapt to larger fluctuations in temperature and heat flux that exceed the capabilities of current state-of-the-art systems. These missions will demand novel space radiators that can vary the heat rejection rate of the system to maintain the crew cabin at habitable temperatures throughout the entire mission. Current systems can provide a turndown ratio (defined as the ratio of maximum to minimum heat rejection) of 3:1 under adverse conditions. However, future missions are projected to demand thermal control systems that can provide a turndown ratio of more than 6:1. A novel radiator concept, known as the morphing radiator, varies the system heat rejection rate by altering the shape of the radiator that is exposed to space. This shape change is accomplished through the use of shape memory alloys, a class of active materials that exhibit thermomechanically-driven phase transformations and can be used as both sensors and actuators in thermal control applications. In past efforts, prototype morphing radiators have been tested in a relevant thermal environment, demonstrating the feasibility and scalability of the concept. This work summarizes the progress towards testing a high-performance morphing radiator in a relevant thermal environment and details the development of an efficient numerical model that predicts the mechanical response of an arbitrary morphing radiator configuration due to changes in temperature. Model predictions are then validated against previous experimental results, demonstrating the usefulness of the model as a design tool for future morphing radiator prototypes.

Scanning-probe microscope analysis of optical thin films: A new analytical tool in a manufacturing environment

1994 ◽  
Vol 52 ◽  
pp. 1068-1069
Author(s):  
S. P. Sapers ◽  
R. Clark ◽  
P. Somerville
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Control ◽  
Scanning Probe Microscope ◽  
Scanning Probe ◽  
List Type ◽  
Manufacturing Environment ◽  
Physical Measurements ◽  
Probe Microscope

OCLI is a leading manufacturer of thin films for optical and thermal control applications. The determination of thin film and substrate topography can be a powerful way to obtain information for deposition process design and control, and about the final thin film device properties. At OCLI we use a scanning probe microscope (SPM) in the analytical lab to obtain qualitative and quantitative data about thin film and substrate surfaces for applications in production and research and development. This manufacturing environment requires a rapid response, and a large degree of flexibility, which poses special challenges for this emerging technology. The types of information the SPM provides can be broken into three categories:(1)Imaging of surface topography for visualization purposes, especially for samples that are not SEM compatible due to size or material constraints;(2)Examination of sample surface features to make physical measurements such as surface roughness, lateral feature spacing, grain size, and surface area;(3)Determination of physical properties such as surface compliance, i.e. “hardness”, surface frictional forces, surface electrical properties.

Miniature Heat Pipes for Thermal Control of Radio-Electronic Equipment

2007 ◽  
Vol 38 (3) ◽  
pp. 245-258 ◽  
Author(s):  
Leonid L. Vasiliev ◽  
Andrei G. Kulakov ◽  
L. L. Vasiliev, Jr ◽  
Mikhail I. Rabetskii ◽  
A. A. Antukh
Keyword(s):  
Heat Pipes ◽  
Thermal Control ◽  
Electronic Equipment ◽  
Radio Electronic
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