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Results for “Cryogenic cooling”

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 289 records · Page 16

Photovoltaic, gravitationally-stabilized solid-state, satellite solar power station /GSS4PS/

The salient feature of a gravitationally-stabilized satellite solar power system (SSPS) for a photovoltaic system is that the large solar array is separated into smaller segments or subunits, joined together in a linear array oriented along the local vertical. Applicability of gravitational stabilization to the design of photovoltaic SSPS is demonstrated. Both actively controlled systems using multiple solar panels oriented to the sun and passively controlled systems requiring no sun orientation are considered and determined to be feasible. Expressions for gravity-gradient induced tension and restoring torques about the local vertical are assessed. Particular attention is directed to the applicability of solid-state approaches to the design of SSPS. It is shown that an all solid-state SSPS utilizing the LITOMIC (light-to-microwave conversion) concept is feasible but that a hybrid system employing a combination of both solid-state and cryogenic cooled low-voltage techniques to the design of the power management and distribution subsystem may also provide a solution.

Cantafio, L. J.↗

Results from the Air Force Geophysics Laboratory survey catalog

Results of an IR survey program designed to obtain the spatial and brightness distributions of a representative sample of IR-emitting objects in the 3-30 micron range are analyzed. Small cryogenically cooled telescopes carried above the atmosphere on sounding rockets were employed in the research. Minimization of sky noise and photon background, experimental equipment, and data reduction techniques are discussed.

Price, S. D.↗

Survey report on the state-of-the-art of cryogenic thermometry and signal conditioners and their potential for standardized space hardware

The possibility of standard low temperature detector(s) for use in upcoming cryogenically cooled satellite and Space Shuttle Payloads was investigated. These payloads operate from .3 Kelvin to 300 Kelvin. Standard detectors were selected and matching signal conditioning equipment were specified. This equipment will operate in a spacecraft environment and be compatible with the selected detector, typical spacecraft voltages, typical spacecraft telemetry systems, and the radiation encountered by a typical earth orbiting spacecraft. Work statements to better define and advance detector performance are presented.

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The Goddard Space Flight Center Solid State Spectrometer for the HEAO-B Mission

A non-dispersive, cryogenically-cooled X-ray detector system, to be flown as one of the focal-plane experiments on the High Energy Astrophysical Observatory-B, is described. The instrument is designed to measure the X-ray flux in the 500 eV to 5000 eV range with an energy resolution of 150 eV (pulser) and a temporal resolution approaching 2 microsec.

Joyce, R. M.↗

Infrared astronomical satellite

Design and mission characteristics of the Infrared Astronomical Satellite (IRAS) are reviewed with attention to the satellite/telescope configuration. The IRAS will be launched into a 900 km near-polar orbit (inclination 99 deg), with a cryogenically cooled 60 cm telescope capable of collecting 700 million bits of data per day. The telescope is expected to add from 6000 to one million new IR sources to the astronomical catalogs. Objects for study include stars, extended sources, asteroids, zodiacal light, artificial satellites, high energy protons, and dust.

Mclaughlin, W. I.↗

High-resolution spectrometer

Proposed spectrometer combines optical and imaging devices and cryogenic cooling to measure infrared radiation in 1-to-15 micrometer wavelength range with spatial resolution of 1 arc-second and average spectral resolution of about 0.1 cm(-1). Compact, lightweight unit is suitable for laboratory or field use. Pollution monitoring is possible application.

Beer, R.↗

OAST Space Theme Workshop. Volume 3: Working group summary. 7: Material (M-1). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)

The approach of matching technology areas with various themes needs was not effective for the materials and thermal control discipline because of the diversity of requirements for each. Top priorities were evolved from the advanced space transportation system and the space power platform because these are essential building blocks in fulfilling some of the other themes. Important needs identified include life long-life cryogenic cooling systems for sensors, masers, and other devices and the needs for lightweight nuclear shielding materials for nuclear electric propulsion.

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Low-noise receivers: S-band parametric up converter development

The combination of a cryogenically-cooled parametric upconverter and a higher frequency maser post amplifier was proposed as a method of achieving maser-like receiver noise temperatures over much larger instantaneous bandwidths and tuning ranges than are presently obtainable with masers in the range of 1 to 18 GHz. An experimental 2.0- to 2.5-GHz parametric upconverter/maser system was developed to explore these possibilities. Initial tests of this system resulted in an effective input noise temperature of 3.1 K at 2295 MHz and 3.2 K at 2388 MHz. The parametric upconverter logged over 1500 hours at 4.5 K and underwent 5 thermal cycles (300 K to 4.5 K to 300 K) without degradation.

Petty, S.↗

A reflected-wave ruby maser with K-band tuning range and large instantaneous bandwidth

A novel maser concept is outlined and a unique design described which permits wide bandwidth and waveguide tuning range by employing four stages cascaded via cryogenically cooled circulators. Theoretical considerations for gain, bandwidth, gain ripple, and noise temperature are included. Operated on a closed-cycle helium refrigerator with a superconducting persistence-mode magnet, the four-stage amplifier is tunable from 18.3 to 26.6 GHz with 30 dB of net gain and achieves 240 MHz of 3-dB bandwidth near the center of this band. The measured noise temperature is 13 + or - 2 K referred to the room-temperature input flange. Applications are foreseen utilizing cooled parametric downconverters and upconverters with this amplifier at IF to extend the low-noise performance up to millimeter frequencies and down to L-band for radio astronomy and planetary spacecraft communications.

Moore, C. R.↗

Tests of low background photo conductors

In support of two infrared astronomy space projects, the IRAS satellite and the IRT on Spacelab 2, low-background tests were carried out on the performance and characterization of Si:Ga, Si:As, Si:Sb and Ge:Ga photoconductive detectors. These test results represent a useful appraisal of this family of detectors when operated at 1.8-4.2 K and at background power levels of 10 to the -14th to 10 to the -13th W. In addition to detector performance data, results are also presented on cryogenically cooled MOSFET amplifiers operated in the source follower and in the balanced-dc-TIA configurations.

Young, E. T.↗

Pulsed plasma thruster backflow characteristics

The exhaust plume of a millipound pulsed plasma thruster has been investigated using a unique vacuum facility with cryogenically cooled low back-scatter chamber walls. The mass flux distribution of the plume was determined, with emphasis on the region upstream of the thruster. Measurements of the plume material scattered from the chamber walls were used with articulated collimator-quartz crystal microbalance measurements of the total flux to estimate the upstream flux originating in the plume. This flux was found to be of order 10 to the minus 10 g/sq cm/ pulse and to vary approximately with the inverse square of the radius. Measurements indicate the directed plume is essentially axisymmetric with a slight elongation in the direction parallel to the interelectrode gap. This downstream flux decreases with radius along a Gaussian profile with 90% of the plume confined to a 40 deg half-angle cone.

Rudolph, L. K.↗

Support assembly for cryogenically coolable low-noise choke waveguide

A compact cryogenically coolable choked waveguide for low-noise input coupling into a cryogenically cooled device, such as a maser or parametric amplifier, utilizes coaxial stainless steel support tubes surrounding the waveguide and connected in cascade to provide a folded low thermal conduction path. The edges of the tubes connected are welded.

Mccrea, F. E.↗

Infrared telescope on Spacelab 2

The infrared telescope (IRT) on Spacelab 2 which will be the first cryogenically cooled telescope operated from the Orbiter is discussed. Its objectives are to measure the induced environment about the Orbiter and to demonstrate the ability to manage a large volume of superfluid helium in space. The prime astrophysical objectives are to map extended sources of low surface brightness infrared emission, including the zodiacal light, the galactic plane, and extragalactic regions. The IRT design is described, including the f/4 15.2 cm highly baffled Herschelian telescope cooled to 8 K which may scan to within 35 deg of the sun. The focal plane cooled to 3 K consists of nine discrete photoconductors covering the wavelength of 4.5-120 microns in five bands, with a single stellar detector used for aspect determination. Overlapping scans, contiguous orbits, and a six degree per second scan rate permit rapid redundant coverage of 60 % of the sky.

Koch, D.↗

Review of design and operational characteristics of the 0.3-meter transonic cryogenic tunnel

The fundamentals of cryogenic testing are validated both analytically and experimentally employing the 0.3-m transonic cryogenic tunnel. The tunnel with its unique Reynolds number capability has been used for a wide variety of aerodynamic tests. Techniques regarding real-gas effects have been developed and cryogenic tunnel conditions are set and maintained accurately. It is shown that cryogenic cooling, by injecting nitrogen directly into the tunnel circuit, imposes no problems with temperature distribution or dynamic response characteristics.

Ray, E. J.↗

Internal image motion compensation system for the Shuttle Infrared Telescope Facility

The Shuttle Infrared Telescope Facility (SIRTF) is being designed as a 1-m, cryogenically cooled telescope capable of a thirty-fold improvement over currently available infrared instruments. The SIRTF, mounted in the Orbiter bay on the Instrument Pointing System (IPS), requires that the image at the focal plane be stabilized to better than 0.1 arcsec with an absolute accuracy of 1 arcsec in order to attain this goal. Current estimates of IPS performance for both stability and accuracy indicate that additional stabilization will be necessary to meet the SIRTF requirements. An Image Motion Compensation (IMC) system, utilizing a Charge Coupled Device (CCD) star tracker located at the focal plane and a steerable mirror in the SIRTF optical path, has been designed to work in conjunction with the IPS.

Lorell, K. R.↗

Simulation of the Infrared Astronomical Satellite /IRAS/ telescope system

The Infrared Astronomical Satellite (IRAS), a joint Dutch-British-U.S. project scheduled for launch in February 1981, will conduct the first all-sky infrared survey between 8 and 120 microns using a 60-cm aperture, cryogenically-cooled telescope. A computer simulation program has been developed at Ames Research Center to aid in the design of this complex telescope. The development and implementation of the IRAS Telescope Simulator (IRTS), its input data sources, and its output data products are described.

Henderson, E.↗

Dynamic Isolation for Cryogenic Refrigerators

Prototype pressure-compensated mounting isolates a Tunable Diode Laser (TDL) housing from mechanical vibration. Mounting is being tested as part of Langley Research Center program for development of highly sensitive instruments that remotely measure important chemical constituents of atmosphere. Instruments typically have requirement for cryogenic cooling of sensitive detectors and components that are necessary to detect presence of tenuous constituents of atmosphere. Key elements of mounting are two bellows, reaction plate, flexible straps and vibration isolators.

Averill, R. D.↗

Evaluation of moire techniques for wind tunnel metrology

The development of a moire technique suitable for the analysis of object deflections in a cryogenically cooled, transonic wind tunnel is described. The operating environment for the wind tunnel has a temperature range of 77 to 3390 k, pressure to 91390 Kgs/sq m, and noise to 150 dB SPL. Efforts were made to accomplish the following: to demonstrate projection moire as it would be used to study structural deflections; to use optical processing to multiply the sensitivity of the moire; and to investigate a system design based on the requirements of the wind tunnel geometry.

Harris, J. S.↗