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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2003

STS-107 Flight Day 15 Highlights

This video shows the activities of the STS-107 crew on flight day 15 of the Columbia orbiter's final mission. The crew includes Commander Rick Husband, Pilot William McCool, Mission Specialists Michael Anderson, David Brown, Laurel Clark, and Kalpana Chawla, and Payload Specialist Ilan Ramon. The primary activities of flight day 15 are crew interviews, and operating the Water Mist Fire Suppression (MIST) experiment. Early in the video, astronauts McCool and Ramon respond together to a question. Much of the video is taken up by an interview of astronauts Brown, Anderson, and McCool. Two parts of the video show the MIST experiment in operation, operated the first time by astronaut Brown. Another part of the video is narrated by Mission Specialist Clark, who identifies views of Mount Vesuvius, and an atoll in the south Pacific. In this part, Payload Specialist Ramon is seen on an exercise machine, Commander Husband shows body fluid samples from the crew taken during the mission, and Clark demonstrates how the crew eats meals. The video ends with footage from earlier in the mission which shows a deployed radiator in the shuttle's payload bay that reflects an image of the Earth.

Source record↗
NASA NTRS2002

Flight Testing of the Capillary Pumped Loop 3 Experiment

The Capillary Pumped Loop 3 (CAPL 3) experiment was a multiple evaporator capillary pumped loop experiment that flew in the Space Shuttle payload bay in December 2001 (STS-108). The main objective of CAPL 3 was to demonstrate in micro-gravity a multiple evaporator capillary pumped loop system, capable of reliable start-up, reliable continuous operation, and heat load sharing, with hardware for a deployable radiator. Tests performed on orbit included start-ups, power cycles, low power tests (100 W total), high power tests (up to 1447 W total), heat load sharing, variable/fixed conductance transition tests, and saturation temperature change tests. The majority of the tests were completed successfully, although the experiment did exhibit an unexpected sensitivity to shuttle maneuvers. This paper describes the experiment, the tests performed during the mission, and the test results.

Ottenstein, Laura↗
NASA NTRS2004

Miniature Loop Heat Pipe (MLHP) Thermal Management System

The MLHP Thermal Management System consists of a loop heat pipe (LHP) with multiple evaporators and condensers, thermal electrical coolers, and deployable radiators coated with variable emittance coatings (VECs). All components are miniaturized. It retains all the performance characteristics of state-of-the-art LHPs and offers additional advantages to enhance the functionality, versatility, and reliability of the system, including flexible locations of instruments and radiators, a single interface temperature for multiple instruments, cooling the on instruments and warming the off instruments simultaneously, improving. start-up success, maintaining a constant LHP operating temperature over a wide range of instrument powers, effecting automatic thermal switching and thermal diode actions, and reducing supplemental heater powers. It can fully achieve low mass, low power and compactness necessary for future small spacecraft. Potential applications of the MLHP thermal technology for future missions include: 1) Magnetospheric Constellation; 2) Solar Sentinels; 3) Mars Science Laboratory; 4) Mars Scouts; 5) Mars Telecom Orbiter; 6) Space Interferometry Mission; 7) Laser Interferometer Space Antenna; 8) Jupiter Icy Moon Orbiter; 9) Terrestrial Planet Finder; 10) Single Aperture Far-Infrared Observatory, and 11) Exploration Missions. The MLHP Thermal Management System combines the operating features of a variable conductance heat pipe, a thermal switch, a thermal diode, and a state-of-the-art LHP into a single integrated thermal system. It offers many advantages over conventional thermal control techniques, and can be a technology enabler for future space missions. Successful flight validation will bring the benefits of MLHP technology to the small satellite arena and will have cross-cutting applications to both Space Science and Earth Science Enterprises.

Ku, Jentung↗
NASA NTRS2004

A 100 kW-Class Technology Demonstrator for Space Solar Power

A first step in the development of solar power from space is the flight demonstration of critical technologies. These fundamental technologies include efficient solar power collection and generation, power management and distribution, and thermal management. In addition, the integration and utilization of these technologies into a viable satellite bus could provide an energy-rich platform for a portfolio of payload experiments such as wireless power transmission (WPT). This paper presents the preliminary design of a concept for a 100 kW-class free-flying platform suitable for flight demonstration of technology experiments. Recent space solar power (SSP) studies by NASA have taken a stepping stones approach that lead to the gigawatt systems necessary to cost-effectively deliver power from space. These steps start with a 100 kW-class satellite, leading to a 500 kW and then a 1 MW-class platform. Later steps develop a 100 MW bus that could eventually lead to a 1-2 GW pilot plant for SSP. Our studies have shown that a modular approach is cost effective. Modular designs include individual laser-power-beaming satellites that fly in constellations or that are autonomously assembled into larger structures at geosynchronous orbit (GEO). Microwave power-beamed approaches are also modularized into large numbers of identical units of solar arrays, power converters, or supporting structures for arrays and microwave transmitting antennas. A cost-effective approach to launching these modular units is to use existing Earth-to-orbit (ETO) launch systems, in which the modules are dropped into low Earth orbit (LEO) and then the modules perform their own orbit transfer to GEO using expendable solar arrays to power solar electric thrusters. At GEO, the modules either rendezvous and are assembled robotically into larger platforms, or are deployed into constellations of identical laser power-beaming satellites. Since solar electric propulsion by the modules is cost-effective for both self-transport of the modules from LEO to GEO, and for on-orbit stationkeeping and repositioning capability during the satellite’s lifetime, this technology is also critical in technology development for SSP. The 100 kW-class technology demonstrator will utilize advanced solar power collection and generation technologies, power management and distribution, advanced thermal management, and solar electric propulsion. State-of-the-art solar concentrators, highly efficient multi-junction solar cells, integrated thermal management on the arrays, and innovative deployable structure design and packaging make the 100 kW satellite feasible for launch on one existing launch vehicle. Early SSP studies showed that a major percentage of the on-orbit mass for power-beaming satellites was from massive power converters at the solar arrays, at the bus, at the power transmitter, or at combinations of these locations. Higher voltage mays and power management and distribution (PMAD) systems reduce or eliminate the need for many of these massive power converters, and could enable direct-drive of high-voltage solar electric thrusters. Lightweight, highly efficient thermal management systems are a critical technology that must be developed and flown for SSP feasibility. Large amounts of power on satellites imply that large amounts of waste heat will need to be managed. In addition, several of the more innovative lightweight configurations proposed for SSP satellites take advantage of solar concentrators that are intractable without advanced thermal management technologies for the solar arrays. These thermal management systems include efficient interfaces with the WPT systems or other high-power technology experiments, lightweight deployable radiators that can be easily integrated into satellite buses, and efficient reliable thermal distribution systems that can pipe heat from the technology experiments to the radiators. In addition to demonstrating the integration and use of these mission-critical technologies, the 100 kw-class satellite will provide a large experiment deck for a portfolio of technology experiments. Current plans for this technology demonstrator allow 2000 kg of payload capability and up to 100 kW of power. The technology experiments could include one or more wireless power transmission demonstrations, either to the Earth’s surface or to a suitable space-based receiver. Technology experiments to quantify the on-orbit performance of critical technologies for SSP or space exploration are welcomed. In addition, the technology experiments provide an opportunity for international cooperation, to advance technology readiness levels of SSP technologies that require flight demonstration. This paper will present the preliminary design for a 100 kW solar-powered satellite and a variety of technology experiments that may be suitable for flight demonstration. In addition, a space-to-Earth-surface WPT experiment will be discussed.

Connie Carrington↗
NASA NTRS2005

Effect of Variable Emittance Coatings on the Operation of a Miniature Loop Heat Pipe

Abstract. As the size of spacecraft shrink to accommodate small and more efficient instruments, smaller launch vehicles, and constellation missions, all subsystems must also be made smaller. Under NASA NFL4 03-OSS-02, Space Technology-8 (ST 8), NASA Goddard Space Flight Center and Jet Propulsion Laboratory jointly conducted a Concept Definition study to develop a miniature loop heat pipe (MLHP) thermal management system design suitable for future small spacecraft. The proposed MLHP thermal management system consists of a miniature loop heat pipe (LHP) and deployable radiators that are coated with variable emittance coatings (VECs). As part of the Phase A study and proof of the design concept, variable emittance coatings were integrated with a breadboard miniature loop heat pipe. The miniature loop heat pipe was supplied by the Jet Propulsion Laboratory (PL), while the variable emittance technology were supplied by Johns Hopkins University Applied Physics Laboratory and Sensortex, Inc. The entire system was tested under vacuum at various temperature extremes and power loads. This paper summarizes the results of this testing and shows the effect of the VEC on the operation of a miniature loop heat pipe.

Douglas, Donya M.↗
NASA NTRS2005

Miniature Loop Heat Pipe with Multiple Evaporators for Thermal Control of Small Spacecraft

This paper presents an advanced miniature heat transport system for thermal control of small spacecraft. The thermal system consists of a loop heat pipe (LHP) with multiple evaporators and multiple deployable radiators for heat transfer, and variable emittance coatings on the radiators for performance enhancement. Thermoelectric coolers are used to control the loop operating temperature. The thermal system combines the functions of variable conductance heat pipes, thermal switches, thermal diodes, and the state-of-the-art LHPs into a single integrated thermal system. It retains all the performance characteristics of state-of-the-art LHPs and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. Steady state and transient analytical models have been developed, and scaling criteria have also been established. A breadboard unit has been built for functional testing in laboratory and thermal vacuum environments. Experimental results show excellent performance of the thermal system and correlate very well with theoretical predictions.

Ku, Jentung↗
NASA NTRS2019

The International Space Station (ISS) Port 1 (P1) External Active Thermal Control System (EATCS) Ammonia Leak

Ammonia is used in the Starboard 1 (S1) and Port 1 (P1) External Active Thermal Control System (EATCS) to cool the pressurized modules, and some of the external electrical power distribution hardware. Leaks that develop in these critical cooling systems that deplete in-line tanks can ultimately result in loss of cooling, which can have devastating impacts to the mission, science and crew onboard the ISS. A slow ammonia leak was initially observed from the P1 EATCS in 2011, but later in 2013 the leak rate began to accelerate. The ammonia inventory eventually began to decay exponentially, raising concerns that the inventory could drop to levels where the system would not be operational.The Robotic External Leak Locator (RELL) was built and launched to the ISS to detect and help locate ammonia leaks using the ISS Robotic Arm and remote ground operator control without constant crew involvement. RELL pinpointed the ammonia leak to the two flexible jumper hose assemblies connecting one of two fluid loops in one of the three deployable radiators to the P1 EATCS. The ammonia inside the two hose assemblies and that radiator fluid loop was isolated and vented to space in 2017. This stopped the leak and an Extravehicular Activity was conducted to remove the two hose assemblies so they could be returned to ground for further Test, Teardown and Evaluation (TT&E). The purpose of this presentation is to discuss this leakage scenario and the TT&E efforts.

Cowan, Darnell T.↗
NASA NTRSDate not supplied

Additive Manufacturing and Experimental Characterization of Nickel-Titanium Shape-Memory Alloy Wick Structures and Heat Pipes for Spacecraft Thermal Control

Shape memory alloys (SMA), such as those based on nickel-titanium (NiTi), are increasingly being applied as multifunctional spacecraft components. For thermal management applications, NiTi flow tubing hinges and self-deploying loop heat pipes have been demonstrated. Emerging additive manufacturing (AM) processes are enabling more complex SMA devices than can be formed from conventional plain wire, tubing, and sheet stock materials. This paper presents our progress toward applying powder bed fusion AM to producing porous NiTi wicks and NiTi-H2O heat pipes, which could be embedded in thermally deploying radiators for spacecraft thermal management. AM near-equiatomic NiTi (55.1 wt% Ni) porous wick specimens were produced with a range of deposition parameters. Transient acetone rate-of-rise experiments were performed to estimate wick permeability (K) and average pore radius (r_pore) values and identify parameter sets with high capillary performance. Surface treatments were evaluated to achieve hydrophilic wick structures. Evaluated treatments included chemical oxide growth with H2O2, oxide and sodium titanate growth with NaOH solution, and ultrasonic cleaning with specialty detergents that can remove hydrocarbon contaminants. The most durable hydrophilic surface conditions were obtained with the NaOH treatment. High performing wick deposition parameters were used to produce a full AM NiTi heat pipe, which was treated with NaOH solution to activate the wick. This heat pipe was operated on a test stand in the inverted configuration (upper evaporator and lower condenser), and demonstrated stable nearly isothermal operation for 150 hrs.

Thermal management↗
NASA NTRSDate not supplied

Additive Manufacturing and Experimental Characterization of Nickel-Titanium Shape-Memory Alloy Wick Structures and Heat Pipes for Spacecraft Thermal Control

Shape memory alloys (SMA), such as those based on nickel-titanium (NiTi), are increasingly being applied as multifunctional spacecraft components. For thermal management applications, NiTi flow tubing hinges and self-deploying loop heat pipes have been demonstrated. Emerging additive manufacturing (AM) processes are enabling more complex SMA devices than can be formed from conventional plain wire, tubing, and sheet stock materials. This paper presents our progress toward applying powder bed fusion AM to producing porous NiTi wicks and NiTi-H2O heat pipes, which could be embedded in thermally deploying radiators for spacecraft thermal management. AM near-equiatomic NiTi (55.1 wt% Ni) porous wick specimens were produced with a range of deposition parameters. Transient acetone rate-of-rise experiments were performed to estimate wick permeability (K) and average pore radius (r_pore) values and identify parameter sets with high capillary performance. Surface treatments were evaluated to achieve hydrophilic wick structures. Evaluated treatments included chemical oxide growth with H2O2, oxide and sodium titanate growth with NaOH solution, and ultrasonic cleaning with specialty detergents that can remove hydrocarbon contaminants. The most durable hydrophilic surface conditions were obtained with the NaOH treatment. High performing wick deposition parameters were used to produce a full AM NiTi heat pipe, which was treated with NaOH solution to activate the wick. This heat pipe was operated on a test stand in the inverted configuration (upper evaporator and lower condenser), and demonstrated stable nearly isothermal operation for 150 hrs.

Thermal management↗
NASA NTRSDate not supplied

Engineering Design Study of Laser Power Beaming for Applications on the Moon

Using a laser to send power to a photovoltaic receiver has been proposed to transmit electrical power on the moon, particularly for applications such as powering a rover in near-polar permanent-ly-shadowed regions (PSR) where solar power is not available, however detailed engineering design studies of the spacecraft for such applications has not previously been undertaken. In this work, we did an engineering design study of two applications of laser power beaming for near-term lunar ap-plications. In the first application studied, an application was studied to provide power during the lunar night for a global network of small landers spread across the lunar surface, at latitudes ranging from equatorial to near polar landing sites. We analyze a proposal to power such small landers from orbit, using a laser to beam power from an orbital power station to photovoltaic arrays on the landers that are tuned to the laser wavelength. A commercially-available high-power 1.07-µ diode-pumped fiber laser was chosen as the source. To minimize beam spread of the a spot at the required distance, a 1.5 meter optical element was provided, using a design based on the Kepler telescope. To provide power to landers at any location, three orbital stations (“beamcraft) are required, each carrying a 3-kW laser. (If the surface science platforms requiring power are only in polar locations, or converse-ly, only in near equatorial locations, only one orbital platform is needed.) The approach is seen to be feasible, and a systems analysis was completed, the concept of operations for the system out-lined and a design for the beamcraft put together. The second design study looked at surface-to-surface power beaming using the VSAT as the la-ser platform, for an application to provide power to the interior of a permanently shadowed lunar crater from a surface platform. To maximize the distance of beaming, taking into account possible surface irregularities and the short distance to the horizon of the moon, it is desirable to emplace the laser at an elevation above the surface. The Vertical Solar Array Technology (VSAT) is a NASA program developing a solar array mounted vertically on a 10-m tall mast, designed for emplacement on a Commercial Lunar Payload Services (CLPS) lander to provide 10-kW (BOL) power near the south polar region of the moon, with a target readiness date of 2028. We used this design as the starting platform and the power source for a laser power beaming station. By mounting the laser beam director at the top of the solar array mast, a viewing distance to power receivers up to 10 km is possible. Requirements for the system were to be able to provide 300 W of continuous usable power to users including CLPS landers, VIPER class rovers, or the proposed Lunar Terrain Vehicle. The specified requirement was to be able to transmit power to a distance of up to 10 km, over a design lifetime of 5 years, and fitting within a total system landed mass under 625 kg. Again, a 1.07-µ fiber laser is mounted on the deck of the lander, with laser output sent to the laser beam director by a fiber-optic cable. A 7 square meter deployable radiator keeps the laser within operating temperature limits. The beam director is based on the design of a prototype unit developed by the University of California Santa Barbara. The system beams power for 57% of the time, with 44% of the time idle (accounting for the time when the VSAT array is itself in shadow). 1595 Watts of optical power are output in the beam. Accounting for receiver efficiency and beam losses, this results in an output onto the 1.5-meter receiving photovoltaic array of 542 watts. Of this, 300 watts is directly available to the user, while 242 watts is directed to the batteries for use while the beam is not available.

laser power↗
NASA NTRS1991

Preliminary design of a radiator shading device for a lunar outpost

The National Aeronautics and Space Administration is designing a thermal control system for an outpost to be placed permanently on the Moon. One of the functions of the thermal control system is to reject waste heat, which can be accomplished through a radiator. At the lunar equator and during the lunar midday, an unshaded radiator absorbs more heat than it rejects. This problem can be solved by using a shading device to reduce radiation incident on the radiator. The design team was asked to develop concepts for reducing the radiation incident on the radiator and for deploying the radiator and shade system for a 10 kW and a 25 kW heat rejection system. The design team was also asked to develop the best concepts into preliminary design. From the several alternatives developed by the design team, the best one was selected using a decision matrix. Preliminary design of the best concept include support structure, stress analyses, and thermal performance. In addition, the team developed ideas for removing lunar dust from the shading device. The final design solution consisted of a winged radiator shading system with a rail support structure and a scissors mechanism for deployment. The total radiator area required was calculated to be 389 sq m for the 10 kW heat rejection system and 973 sq m for the 25 kW heat rejection system.

Barron, Carlos↗
NASA NTRS1977

Flexible deployable-retractable space radiators

A lightweight flexible radiator system for on-orbit cooling of space payloads is described. The radiator is packaged as a compact unit which can be attached to a vehicle structure or hatch prior to or after launch. On-orbit, it is deployed to provide the radiating surface needed for a specific experiment. The unit is being independently developed and qualified as a heat rejection system which will be ready for any spacecraft or experiment, and which will not require significant structural and systems accommodation. Design details and thermal vacuum test results are presented.

Leach, J. W.↗
NASA NTRS1981

Thermal vacuum testing of flexible radiator systems

Flexible fin radiators are being developed to meet spacecraft requirements of light weight, compact launch volume, modular growth, reusability, and the capability of an on-orbit deployment and retraction. Two prototype versions of deployable/retractable, flexible finspace radiators (soft and hard tube) were tested simultaneously under thermal vacuum conditions. A map of the heat rejection performance of each radiator panel under various environmental conditions is given. The soft tube radiator deployment system demonstrated minimal gas pressure and was capable of maintaining partial deployment; temperature control was achieved by varying the deployment length. The radiator could be recovered after an inadvertant freezing of the coolant in the Teflon tube. The hard tube radiator deployment mechanism performed adequately throughout the testing, but did exhibit some undesirable performance characteristics. The hard tube radiator pressure drop was higher than expected, but was not affected by the length of deployment. The radiator operated at less than full deployment, and the manifolds were found to have a significant effect on heat rejection. At low-load conditions, the hard tube radiator appeared to bypass its deployed area.

Rankin, G.↗
NASA NTRSDate not supplied

Experimental Characterization of Additively Manufactured Nickel-Titanium Shape Memory Alloy Heat Pipes

Shape memory alloys (SMA) have been identified for use in spacecraft components as replacement for conventional deployment mechanisms. They may be used in thermal management components such as radiators to create self-deploying radiators. One SMA, NiTi, has also been developed for additive manufacturing processes. Heat pipes are a common way to create highly effective and lightweight spaceflight radiators, and heat pipes can also be made from NiTi and related alloys. The wick is the critical element of a functioning heat pipe, and recent progress over the past years has led to the development of additively manufactured heat pipe wicks in various materials. The combination of these efforts is the focus of this project: creating an additively manufactured, shape memory alloy self-deploying heat pipe radiator. This paper will focus on the experimental characterization of these additively manufactured NiTi heat pipes. The heat pipe coupons were additively manufactured by direct metal laser sintering (DMLS), with an integral liquid cooled condenser. Heat is input to the heat pipe via a thin film heater. Thermocouples were spot welded to the heat pipes to measure temperature at several axial locations. The heat pipes were tested with two working fluids: water and ethanol. Ethanol is not an ideal working fluid for heat pipes but is useful in characterizing them because it wets well to a wide variety of surfaces. Water is in general a superior working fluid for heat pipes, but its contact angle and therefore wicking performance strongly depends on the surface chemistry of the surface it is in contact with. A particular measurement of interest in this test is the evaporator to condenser thermal conductance, which will be compared in the full paper to recently published correlations for additively manufactured heat pipes. Experimental results for two straight geometry and one bellows geometry heat pipe will be presented. The bellows geometry is of interest for condenser of the self-deploying radiator design.

Additive manufacturing↗
NASA NTRS1978

Deployable heat-pipe radiator

Loop temperatures are controlled effectively under varying load conditions. Radiator has four separate pieces of hardware: heat-pipe panel, flexible heat-pipe leader, heat exchanger, fluid header. Single-fluid transport capacities of about 850 watts, corresponding to 51,000 watt-inches, have been achieved in 90 degree bend orientation of heat-pipe header.

Edelstein, F.↗
NASA NTRSDate not supplied

RadLab: A Comprehensive Database and Analysis Toolkit for Space Radiation Measurements Relevant to Space Radiation Biology

RadLab, a new addition to the NASA Open Science Data Repository (OSDR), is a public platform for space radiation data relevant to human space exploration. RadLab consists of a database, a submission portal, and user-friendly visualization and data analysis tools, including a graphical user interface (GUI) and an application programming interface (API). Investigators from ISS partners including Germany, Italy, Canada, Hungary, the Czech Republic, Russia, Japan have committed to providing data from their instruments. RadLab will also include data from other spacecraft in LEO: the Space Shuttle, the Mir space station, biosatellites; and beyond LEO: the lunar and the Martian surface, the heliocentric orbit at 1 AU, Mars orbit, and Earth-Mars space. Once fully operational, RadLab will provide open, centralized access to space radiation physics data relevant to human space exploration; a platform for submission of data by agencies and research institutions responsible for radiation detectors deployed in space; analysis tools to facilitate detector and dataset intercomparison to better understand space habitat radiation environments; capabilities for space biology investigators to determine the radiation environment to which samples were exposed. A RadLab Working Group (RLWG) has been formed, modeled on the GeneLab Analysis Working Groups and comprised of data contributors and users. RLWG tasks include identifying data sources, normalizing data from diverse detectors, expanding the analysis toolkit and, perhaps most importantly, sharing ideas for research exploiting capabilities of RadLab. We will provide an overview of RadLab data and capabilities and discuss examples of its potential as a resource for open science.

radiation↗