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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Deployable radiators for waste heat dissipation from Shuttle payloads

Prototypes of two types of modularized, deployable radiator systems with a high degree of configuration and component commonality to minimize design, development and fabrication costs are currently under development for Shuttle payloads with high waste heat: a rigid radiator system which utilizes aluminum honeycomb panels that are deployed by a scissors mechanism; and two 'flexible' radiator systems which use panels constructed from flexible metal/dielectric composite materials that are deployed by 'unrolling' or 'extending' in orbit. Detail descriptions of these deployable radiator systems along with design and performance features are presented.

Cox, R. L.↗
NASA NTRS1976

Deployable radiators for waste heat dissipation from Shuttle payloads

Thermal control of Shuttle instruments will require the use of a pumped fluid space radiator system to reject large quantities of waste heat. Many payloads, however, will have insufficient vehicle surface area available for radiators to reject this waste heat and will, therefore, require the use of deployed panels. It is desirable to utilize modularized, deployable radiator systems which have a high degree of configuration and component commonality to minimize the design, development, and fabrication costs. Prototypes of two radiator systems which meet these criteria are currently under development for Shuttle payload utilization: a 'rigid' radiator system which utilizes aluminum honeycomb panels of the Shuttle Orbiter configuration that are deployed by an Apollo Telescope Mount type scissors mechanism; and two 'flexible' radiator systems which use panels constructed from flexible metal/dielectric composite materials that are deployed by 'unrolling' or 'extending' in orbit. Detailed descriptions of these deployable radiator systems, along with design and performance features, are presented.

Cox, R. L.↗
NASA NTRS2014

Design and Test of a Deployable Radiation Cover for the REgolith X-Ray Imaging Spectrometer

The REgolith X-ray Imaging Spectrometer (REXIS) instrument contains a one-time deployable radiation cover that is opened using a shape memory alloy actuator (a "Frangibolt") from TiNi Aerospace and two torsion springs. The door will be held closed by the bolt for several years in cold storage during travel to the target asteroid, Bennu, and it is imperative to gain confidence that the door will open at predicted operational temperatures. This paper briefly covers the main design features of the radiation cover and measures taken to mitigate risks to cover deployment. As the chosen FD04 model Frangibolt actuator has minimal flight heritage, the main focus of this paper is the testing, results and conclusions with the FD04 while discussing key lessons learned with respect to the use of the FD04 actuator in this application.

Carte, David B.↗
NASA NTRS2003

Deployable radiator with flexible line loop

Radiator assembly (10) for use on a spacecraft (12) is provided including at least one radiator panel assembly (26) repeatably movable between a panel stowed position (28) and a panel deployed position (36), at least two flexible lines (40) in fluid communication with the at least one radiator panel assembly (26) and repeatably movable between a stowage loop (42) and a flattened deployed loop (44).

Keeler, Bryan V.↗
DOE OSTI2024

The Urban Deployment Model: A Toolset for the Simulation and Performance Characterization of Radiation Detector Deployments in Urban Environments

Static and mobile radiation detectors can be deployed in urban environments for a range of nuclear security applications, including radiological source search-and-tracking scenarios. Modeling detector performance for such applications is challenging, as it does not depend solely on the detector capabilities themselves. Many factors must be taken into consideration, including specific source and background signatures, the topology and constraints of the deployment environment, the presence of nuisance sources, and whether detectors are mobile or static. When considering the simultaneous deployment of multiple, heterogeneous detectors, assessment of the system-wide performance requires the simulation of the individual detectors, and a system-level analysis of the detection performance. In radiological source search-and-tracking scenarios, performance is mostly dominated by the probability of encounter, which depends on the specifics of a given deployment, e.g., static vs. mobile detectors or a combination of both modalities, the number of detectors deployed, the dynamic vs. static setting of false alarm rates, and individual vs. networked operation. The Urban Deployment Model (UDM) toolset was specifically developed to cover the gap in the available generic frameworks for the simulation of radiation detector deployments at city scales. UDM provides a unified and modular framework to support the simulation and performance characterization of heterogeneous detector deployments in urban environments. This paper presents the key components along the UDM workflow.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
NASA NTRS2024

Deployed Electromagnetic Radiation Deflector Shield Creating a Zone of Minimum Radiation and Magnetic/Plasma Effects for Spacecraft

Spaceflight outside of the Earth's protective magnetic field is dangerous from a cosmic radiation perspective. Inside Earth's magnetic field, where the manned International Space Station (ISS) orbits, the radiation encountered is minimal and almost all is deflected by our planet's magnetic fields. However, outside that protective shield, the Sun's solar wind (high energy radiation, solar energetic particles or SEPs) consisting of protons, electrons, alpha particles and plasmas continuously bombards the spacecraft for the months or years of spaceflight. On occasion the Sun produces a CME (Coronal Mass Ejection) that vastly increases the energy and volume of this radiation. These particles damage human DNA as well as living tissue and can destroy sensitive electronics. The Deployed Electromagnetic Radiation Deflector Shield (DERDS) provides a magnetic field that will deflect SEPs and CMEs and other harmful solar and cosmic rays away from a manned spacecraft, robotic spacecraft, or manned extra-planetary base stations using an electromagnet that is deployed between the spacecraft/station and the source of radiation and creates a magnetosphere or zone of minimal radiation in which the spacecraft or base station would reside.

Patent↗
NASA NTRS2018

Ammonia Vent of the External Active Thermal Control System (EATCS) Radiator #3 Flow Path #2 on the International Space Station (ISS)

The External Active Thermal Control System (EATCS) provides cooling for all pressurized modules and the main Power Distribution Electronics (PDE) on the International Space Station (ISS). There are 2 EATCS loops (Loop A and Loop B) which includes 3 deployable radiators. Each deployable radiator contains 2 flow paths to provide heat rejection.Telemetry monitoring identified a coolant (liquid ammonia) leak in EATCS Loop B. Robotic External Leak Locator (RELL) scans found higher concentrations of vaporous ammonia near the EATCS Loop B Radiator #3 Flow Path #2. On May 3, 2017, the EATCS Loop B Radiator #3 Flow Path #2 was isolated and vented. As of the data to date, the ammonia leak has ceased. The purpose of this presentation is to discuss the analysis for venting the EATCS Loop B Radiator #3 Flow Path #2. Venting analysis is performed to determine the worst case time to empty the flow path and maximum thrusts imposed on the ISS. Flight controllers and engineers in the Mission Control Center (MCC) uses this data to develop operational procedures and perform the vent safely. It was predicted that the worst case time to empty the EATCS Loop B Radiator #3 Flow Path #2 was ~ 60 minutes. The predicted maximum thrusts were ~ 11 lbf (49 N) at the start of the vent and ~10 lbf (45 N) after the system reaches saturation.The vent was successfully performed and took ~ 20 minutes to empty the EATCS Loop B Radiator #3 Flow Path #2. Using telemetry from the day of the vent, analysis determined the time to empty the EATCS Loop B Radiator #3 Flow Path #2 would be ~13 minutes. The predictive analysis used worst case inputs and assumptions which bounded the actual results. Telemetry is not available to correlate actual thrust with the predicted maximum thrusts. However, by using Russian Thrusters for ISS attitude control, attitude control telemetry indicated the flight attitude was maintained.

Cowan, Darnell T.↗
NASA NTRS1975

Deployable Heat Pipe Radiator

A 1.2- by 1.8-m variable conductance heat pipe radiator was designed, built, and tested. The radiator has deployment capability and can passively control Freon-21 fluid loop temperatures under varying loads and environments. It consists of six grooved variable conductance heat pipes attached to a 0.032-in. aluminum panel. Heat is supplied to the radiator via a fluid header or a single-fluid flexible heat pipe header. The heat pipe header is an artery design that has a flexible section capable of bending up to 90 degrees. Radiator loads as high as 850 watts were successfully tested. Over a load variation of 200 watts, the outlet temperature of the Freon-21 fluid varied by 7 F. An alternate control system was also investigated which used a variable conductance heat pipe header attached to the heat pipe radiator panel.

Edelstein, F.↗
NASA NTRS1981

Augmented orbiter heat rejection study

Spacecraft radiator concepts are presented that relieve attitude restrictions required by the shuttle orbiter space radiator for baseline and extended capability STS missions. Cost effective heat rejection kits are considered which add additional capability in the form of attached spacelab radiators or a deployable radiator module.

Hixon, C. W.↗
NASA NTRS1991

Infrastructure for deployment of power systems

A preliminary effort in characterizing the types of stationary lunar power systems which may be considered for emplacement on the lunar surface from the proposed initial 100-kW unit in 2003 to later units ranging in power from 25 to 825 kW is presented. Associated with these power systems are their related infrastructure hardware including: (1) electrical cable, wiring, switchgear, and converters; (2) deployable radiator panels; (3) deployable photovoltaic (PV) panels; (4) heat transfer fluid piping and connection joints; (5) power system instrumentation and control equipment; and (6) interface hardware between lunar surface construction/maintenance equipment and power system. This report: (1) presents estimates of the mass and volumes associated with these power systems and their related infrastructure hardware; (2) provides task breakdown description for emplacing this equipment; (3) gives estimated heat, forces, torques, and alignment tolerances for equipment assembly; and (4) provides other important equipment/machinery requirements where applicable. Packaging options for this equipment will be discussed along with necessary site preparation requirements. Design and analysis issues associated with the final emplacement of this power system hardware are also described.

Sprouse, Kenneth M.↗
NASA NTRS2000

Managing Risk for Thermal Vacuum Testing of the International Space Station Radiators

The International Space Station (ISS) is designed with large deployable radiator panels that are used to reject waste heat from the habitation modules. Qualification testing of the Heat Rejection System (HRS) radiators was performed using qualification hardware only. As a result of those tests, over 30 design changes were made to the actual flight hardware. Consequently, a system level test of the flight hardware was needed to validate its performance in the final configuration. A full thermal vacuum test was performed on the flight hardware in order to demonstrate its ability to deploy on-orbit. Since there is an increased level of risk associated with testing flight hardware, because of cost and schedule limitations, special risk mitigation procedures were developed and implemented for the test program, This paper introduces the Continuous Risk Management process that was utilized for the ISS HRS test program. Testing was performed in the Space Power Facility at the NASA Glenn Research Center, Plum Brook Station located in Sandusky, Ohio. The radiator system was installed in the 100-foot diameter by 122-foot tall vacuum chamber on a special deployment track. Radiator deployments were performed at several thermal conditions similar to those expected on-orbit using both the primary deployment mechanism and the back-up deployment mechanism. The tests were highly successful and were completed without incident.

Carek, Jerry A.↗
NASA NTRS1975

A 2.2 sq m /24 sq ft/ self-controlled deployable heat pipe radiator - Design and test

An all heat pipe, deployable radiator has been developed which can effectively control pumped fluid loop temperatures under varying loads using variable conductance panel heat pipes. The 2.2 sq m (24 sq ft) aluminum panel can be coupled to either a fluid header or a flexible heat pipe header capable of transporting 850 watts in a 90-deg bent configuration. Test results support the feasibility of using this system to passively control Freon-21 loop temperatures.

Edelstein, F.↗
NASA NTRS2013

Folding Elastic Thermal Surface - FETS

The FETS is a light and compact thermal surface (sun shade, IR thermal shield, cover, and/or deployable radiator) that is mounted on a set of offset tape-spring hinges. The thermal surface is constrained during launch and activated in space by a thermomechanical latch such as a wax actuator. An application-specific embodiment of this technology developed for the MATMOS (Mars Atmospheric Trace Molecule Occultation Spectrometer) project serves as a deployable cover and thermal shield for its passive cooler. The FETS fits compactly against the instrument within the constrained launch envelope, and then unfolds into a larger area once in space. In this application, the FETS protects the passive cooler from thermal damage and contamination during ground operations, launch, and during orbit insertion. Once unfolded or deployed, the FETS serves as a heat shield, intercepting parasitic heat loads by blocking the passive cooler s view of the warm spacecraft. The technology significantly enhances the capabilities of instruments requiring either active or passive cooling of optical detectors. This can be particularly important for instruments where performance is limited by the available radiator area. Examples would be IR optical instruments on CubeSATs or those launched as hosted payloads because radiator area is limited and views are often undesirable. As a deployable radiator, the panels making up the FETS are linked thermally by thermal straps and heat pipes; the structural support and deployment energy is provided using tape-spring hinges. The FETS is a novel combination of existing technologies. Prior art for deployable heat shields uses rotating hinges that typically must be lubricated to avoid cold welding or static friction. By using tape-spring hinges, the FETS avoids the need for lubricants by avoiding friction altogether. This also eliminates the potential for contamination of nearby cooled optics by outgassing lubricants. Furthermore, the tape-spring design of the FETS is also self-locking so the panels stay in a rigid and extended configuration after deployment. This unexpected benefit makes the tape-spring hinge design of the FETS a light, simple, reliable, compact, non-outgassing hinge, spring, and latch. While tape-spring hinges are not novel, they have never been used to deploy passive unfolding thermal surfaces (radiator panels, covers, sun shades, or IR thermal shields). Furthermore, because this technology is compact, it has minimal impact on the launch envelope and mass specifications. FETS enhances the performance of hosted payload instruments where the science data is limited by dark noise. Incorporating FETS into a thermal control system increases radiator area, which lowers the optical detector temperature. This results in higher SNR (signal-to-noise ratio) and improved science data.

Urquiza, Eugenio↗
NASA NTRS1985

Thermal management system options for high power space platforms

Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

Sadunas, J. A.↗
NASA NTRS2005

Lightweight Radiator System for a Spacecraft

Three documents describe various aspects of a proposed lightweight, deployable radiator system for dissipating excess heat from the life-support system of a habitable spacecraft. The first document focuses on a radiator tube that would include a thin metal liner surrounded and supported by a thicker carbon-fiber-reinforced composite tubular structure that, in turn, would be formed as part of a unitary composite radiator-fin structure consisting mostly of a sheet of reticulated vitreous carbon laminated between carbon-fiber-reinforced face sheets. The thermal and mechanical properties, including the anisotropies, of the component materials are taken into account in the design. The second document describes thermo-structural bumpers, in the form of exterior multiple-ply carbon-fiber sheets enclosing hollows on opposite sides of a radiator fin, which would protect the radiator tube against impinging micrometeors and orbital debris. The third document describes a radiator system that would include multiple panels containing the aforementioned components, among others. The system would also include mechanisms for deploying the panels from compact stowage. Deployment would not involve breaking and remaking of fluid connections to the radiator panels.

Copeland, Robert J.↗
NASA NTRSDate not supplied

Conceptual Thermal Control System Design for a Lunar Surface Habitat

NASA is currently considering a Surface Habitat (SH) to provide 30-60 day habitability for a crew of up to four to explore the Lunar surface at a South Pole location. The SH concept is comprised of an inflatable volume for the habitable space, a metallic airlock and a descent stage with access to a pressurized rover and other surface assets provided through the airlock. A conceptual architecture for the SH Thermal Control System (TCS) is presented with resource estimates. The TCS design employs a dual loop architecture with a water/propylene glycol mix for the internal crew spaces with a freeze tolerant coolant utilized for the external loop. The internal loop is partitioned into low and moderate temperature service with a sublimator available for operational scenarios prior to thermal radiator deployment (or redeployment). Analytical models are utilized to optimize radiator geometry/orientation as well as the TCS internal/external loop architecture. Heritage hardware is utilized for the TCS concept wherever possible and low mass, dust tolerant, deployable/retractable thermal radiators (in partial gravity) present a technology challenge. The TCS must accommodate infrequent eclipse periods lasting up to 100 hours in duration and mitigation strategies to reduce the energy needed to maintain the SH and associated systems above survival temperature limits during this period are explored. Mitigation options include retractable or freezable radiators, other reconfigurable radiator geometries, alternate fluids, re-generable heat exchangers, temperature excursions, thermal energy storage and optimized inflatable optical properties. Finally, TCS sensitivity to SH Electrical Power System (EPS) growth is considered with both operational and dormant impacts quantified.

Thermal Control↗