Search NASA⌕ Search

SEARCH · Search NASA

Results for “Power Beaming”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

The Low Pressure Gas Effects On The Potency Of An Electron Beam On Ceramic Fabric Materials For Space Welding

This investigation was undertaken to evaluate if molten metal or electron beam impingement could damage or burn through the fabric of the astronauts Extravehicular Mobility Unit (EMU) during electron beam welding exercises performed in space. An 8 kilovolt electron beam with a current in the neighborhood of 100 milliamps from the Ukrainian space welding "Universal Hand Tool" burned holes in Nextel AF-62 ceramic cloth designed to withstand temperatures up to 1427 C. The burnthrough time was on the order of 8 seconds at standoff distances between UHT and cloth ranging from 6 to 24 inches. At both closer (2") and farther (48") standoff distances the potency of the beam against the cloth declined and the burnthrough time went up significantly. Prior to the test it had been expected that the beam would lay down a static charge on the cloth and be deflected without damaging the cloth. The burnthrough is thought to be an effect of partial transmission of beam power by a stream of positive ions generated by the high voltage electron beam from contaminant gas in the "vacuum" chamber. A rough quantitative theoretical computation appears to substantiate this possibility.

Nunes, Arthur C., Jr.↗
NASA NTRS1992

Enabling lunar and space missions by laser power transmission

Applications are proposed for laser power transmission on the Moon. A solar-pumped laser in lunar orbit would beam power to the lunar surface for conversion into either electricity or propulsion needs. For example, lunar rovers could be much more flexible and lighter than rovers using other primary power sources. Also, laser power could be absorbed by lunar soil to create a hard glassy surface for dust-free roadways and launch pads. Laser power could also be used to power small lunar rockets or orbital transfer vehicles, and finally, photovoltaic laser converters could power remote excavation vehicles and human habitats. Laser power transmission is shown to be a highly flexible, enabling primary power source for lunar missions.

Deyoung, R. J.↗
NASA NTRS1999

Low-Pressure Gas Effects on the Potency of an Electron Beam Against Ceramic Cloth

An 8-kv electron beam with a current in the neighborhood of 100 mA from the Ukrainian space welding "Universal Hand Tool" (UHT) burned holes in Nextel AF-62 ceramic cloth designed to withstand temperatures up to 1,427 C. The burnthrough time was on the order of 8 scc at standoff distances between UHT and cloth ranging from 6-24 in. At both closer (2 in.) and farther (48 in.) standoff distances the potency of the beam against the cloth declined and the burnthrough time went up significantly. Prior to the test it had been expected that the beam would lay down a static charge on the cloth and be deflected without damaging the cloth. The burnthrough is thought to be an effect of partial transmission of beam power by a stream of positive ions generated by the high-voltage electron beam from contaminant gas in the "vacuum" chamber. A rough quantitative theoretical computation appears to substantiate this possibility.

Nunes, A. C., Jr.↗
NASA NTRS2001

Advanced Thin Film Solar Arrays for Space: The Terrestrial Legacy

As in the case for single crystal solar cells, the first serious thin film solar cells were developed for space applications with the promise of better power to weight ratios and lower cost. Future science, military, and commercial space missions are incredibly diverse. Military and commercial missions encompass both hundreds of kilowatt arrays to tens of watt arrays in various earth orbits. While science missions also have small to very large power needs there are additional unique requirements to provide power for near sun missions and planetary exploration including orbiters, landers, and rovers both to the inner planets and the outer planets with a major emphasis in the near term on Mars. High power missions are particularly attractive for thin film utilization. These missions are generally those involving solar electric propulsion, surface power systems to sustain an outpost or a permanent colony on the surface of the Moon or Mars, space based lasers or radar, or large Earth orbiting power stations which can serve as central utilities for other orbiting spacecraft, or potentially beaming power to the Earth itself. This paper will discuss the current state of the art of thin film solar cells and the synergy with terrestrial thin film photovoltaic evolution. It will also address some of the technology development issues required to make thin film photovoltaics a viable choice for future space power systems.

Bailey, Sheila↗
NASA NTRS2002

Future Photovoltaic Power Generation for Space-Based Power Utilities

This paper discusses requirements for large earth orbiting power stations that can serve as central utilities for other orbiting spacecraft, or for beaming power to the earth itself. The current state of the art of space solar cells, and a variety of both evolving thin film cells as well as new technologies that may impact the future choice of space solar cells for high power mission applications are addressed.

Bailey, Sheila↗
NASA NTRS1980

Solar Power Satellite Microwave Power Transmission System Description Executive Summary

The history of the concept of microwave power beaming to Earth is reviewed with emphasis on transmission frequency selection. Constraints on the system power level results from (1) required rejection of waste heat resulting from inefficiencies in the cover conversion of dc electric power to microwave power; (2) the rf power intensity in the ionosphere; and (3) the effect of sidelobe level on aperture illumination factors. Transmitter arrangement, the power distribution system, attitude control, subarrays, waveguides, and alignment are discussed.

Woodcock, G. R.↗
NASA NTRS1992

The 250-kW CW klystron amplifier for planetary radar

The design, construction, and performance testing is described of two Varian klystrons, model VKX-7864A, which replaced the aging and less efficient VA-949J klystrons in the X band planetary radar transmitter on the Goldstone, CA, 70 meter antenna. The project was carried out jointly by the JPL and Varian Assoc. Output power was increased from 200 to 250 kW continuous wave per klystron, and full dc beam power is dissipated in the collector (it was not possible to operate the VA-949J klystrons without RF drive because of limited collector dissipation capability). Replacements were made with a minimum of transmitter modifications. The planetary radar transmitter is now operating successfully with these two klystrons.

Cormier, R.↗
NASA NTRS1992

250-kW CW klystron amplifier for planetary radar

The design, construction, and performance testing is described of two Varian klystrons, model VKX-7864A, which replaced the aging and less efficient VA-949J klystrons in the X band planetary radar transmitter on the Goldstone, CA, 70 meter antenna. The project was carried out jointly by the JPL and Varian Assoc. Output power was increased from 200 to 250 kW continuous wave per klystron, and full dc beam power is dissipated in the collector (it was not possible to operate the VA-949J klystrons without RF drive because of limited collector dissipation capability). Replacement were made with a minimum of transmitter modifciations. The planetary radar transmitter is now operating successfully with these two klystrons.

Cormier, Reginald A.↗
NASA NTRS1979

Description of A 2.3 kW power transformer for space applications

The paper describes the principal features and special testing of a high-frequency high-power low-specific-weight (0.57 kg/kW) 2.3-kW electronic power transformer developed for space applications. The transformer is operated in a series resonant inverter supplying beam power to a 30-cm mercury ion thruster. High efficiency (above 98.5%) is obtained through careful detailed design. A number of unique heat removal techniques are discussed which control the winding temperature using only the available conductive cooling.

Hansen, I.↗
NASA NTRS1989

Low-earth-orbit to low-lunar-orbit laser freighter

The objective of this mission study was to compare laser propulsion to chemical LOX/H2 and nuclear electric propulsion for the specific mission of delivering a 144-metric ton lunar base from low-Earth-orbit to low-lunar-orbit. The basis of comparison was total mass in low-Earth-orbit needed to accomplish this mission. The Office of Exploration approach to establishing the lunar base was to use two vehicles: a nuclear electric propulsion (NEP) vehicle to deliver cargo and a chemical vehicle to deliver humans. The NEP vehicle was reactor driven with a vehicle dry mass of 125 metric tons. The Office of Exploration study did not use chemical propulsion for cargo, but in the present study it was used for cargo for comparison to laser propulsion. This mission study assumes a high-power laser, either nuclear or solar electric-driven diode laser, is in orbit around Earth, beaming power to a laser propulsion vehicle. Laser power is only used for the LEO escape burn; other much lower-power burns are done with LOX/H2.

Deyoung, Russell J.↗
NASA NTRS1981

Satellite Power Systems (SPS) concept definition study (Exhibit D). Volume 7: System/subsystems requirements databook

This volume summarizes the basic requirements used as a guide to systems analysis, and is a basis for the selection of candidate Satellite Power Systems (SPS) point designs. Initially, these collected data reflected the level of definition resulting from the evaluation of a broad spectrum of SPS concepts. As the various concepts matured, these requirements were updated to reflect the requirements identified for the projected satellite system/subsystem point designs. Included is an updated version of earlier Rockwell concepts using klystrons as the specific microwave power amplification approach, as well as a more in-depth definition, analysis and preliminary point design on two concepts based on the use of advanced solid state technology to accomplish the task of high power amplification of the 2.45 GHz transmitted power beam to the Earth receiver. Finally, a preliminary definition of a concept using magnetrons as the microwave power amplifiers is presented.

Hanley, G. M.↗
NASA NTRS1980

Solar power satellite microwave system concepts and performance considerations

The phase control system is the fundamental element in the forming, steering and control of the solar power satellite (SPS) microwave power beam. This system must in essence automatically adjust the phase at each of the transmitter's 101,552 power amplifiers to compensate for differences in transmission path lengths to the earth-based receiving antenna (rectenna). SPS phase control system requirements are discussed, taking into account system concepts, a reference system description, reference system performance, ground based phase control concepts, and ionosphere considerations. It is pointed out that the importance of determining the ionospheric effects cannot be overemphasized. The permissable power density limit through the ionosphere is a critical SPS sizing factor and the phase control system must be able to accommodate errors induced by a heated ionosphere.

Seyl, J. W.↗
NASA NTRS2000

POwer WithOut Wire (POWOW): A SEP Concept for Space Exploration

Electric propulsion has emerged as a cost-effective solution to a wide range of satellite applications. Deep Space 1 demonstrated electric propulsion as a primary propulsion source for a spacecraft. The POwer WithOut Wires (POWOW) concept has been developed as a solar electric propelled spacecraft that would travel to Mars, for example, enter selenosynchronous orbit and then use lasers to beam power to surface installations. This concept has been developed with industrial expertise in high efficiency solar cells, advanced concentrator modules, innovative arrays, and high power electric propulsion systems. The paper will present the latest version of the spacecraft, the technologies involved, possible missions and trip times to Mars and laser beaming options. The POWOW spacecraft is a general purpose solar electric propulsion system that includes technologies that are directly applicable to commercial and government spacecraft with power levels ranging from 4 kW in Low Earth Orbits (LEO) to about 1 MW. The system is modular and expandable. Learning curve costing methodologies are used to demonstrate cost effectiveness of a modular system.

Brandhorst, Henry W., Jr.↗
NASA NTRS1979

Description of a 2.3 kW power transformer for space applications

The principle features and special testing of a high voltage high power transformer designed and developed for space application are described. The transformer is operated in a series resonant inverter supplying beam power to a 30 cm mercury ion thruster. Electrical requirements include operation of 2.3 kW continuous power output, primary currents to 35 amps rms, and frequencies up to 20 kHz. High efficiency was obtained through detailed considerations of the tradeoffs available in core materials, wire selection, coil configurations and thermal control. A number of novel heat removal techniques are discussed which control the winding temperature using only the available conductive cooling.

Hansen, I.↗
NASA NTRS1990

5kW xenon ion thruster lifetest

This paper describes the results of the first lifetest of a high power ring-cusp ion thruster. A 30-cm laboratory model thruster was operated steady-state at a nominal beam power of 5kW on xenon propellant for approximately 900 hours. This test was conducted to identify life-limiting erosion mechanisms and thruster design modifications, and to demonstrate operation using simplified power processing. The results from this test are described including the conclusions derived from extensive post-test analyses of the thruster. Modifications to the thruster and ground support equipment, which have been incorporated to solve problems identified by the lifetest, are also described.

Patterson, Michael J.↗
NASA NTRS2006

Effects of the Antenna Aperture on Remote Sensing of Sea Surface Salinity at L-Band

Remote sensing of sea surface salinity with sufficient accuracy to meet the needs of global oceanography is a challenging task. The global variability of the salinity signal in the open ocean is only a few Kelvin even at L-band and an accuracy on the order of 0.1K is desired to study the influence of salinity on ocean circulation and energy exchange with the atmosphere. On the other hand, resolution is not an issue for understanding the dynamics of the open ocean where scales of hundreds of km are not uncommon. This permits remote sensing with large antenna footprints and spatial averaging to reduce noise. However, antennas with large footprints introduce other problems. For example, the angle of incidence and hence the brightness temperature varies over the footprint. Similarly, the polarization of brightness temperature relative to the antenna ports changes. Studies have been conducted using antenna patterns representative of the antenna that will be flown on the Aquarius mission to examine these effects. Aquarius is a pushbroom style radiometer with three beams looking across track away from the sun. The beams are at incidences angles (at the spacecraft) of about 26.5, 34 and 40 degrees each with a half-power beam width of about 5.8 degrees. It is shown that the measured brightness temperature is biased relative to the value at boresight because of changes across the field of view. The bias can be as much as 4K and positive or negative depending on polarization. Polarization mixing because of the variations of the local plane of incidence across the footprint also occur and can result in biased polarimetric measurements. A bias in the third Stokes parameter of as much as 0.4K is possible. Such effects may affect algorithms that use the third Stokes parameter to correct for Faraday rotation. Another issue associated with the antenna is sun glint. This is an issue determined by surface roughness and antenna sidelobes. Examples will be given for the random component (glint) for the case of the Aquarius antenna beams. Fortunately, the Aquarius beams mostly look to the dark side of the day-night termination, but during some portions of the year they will see sun-lighted ocean. In this case, glint could be an issue for the inner-most beam.

Dinnat, Emmanuel P.↗
NASA NTRS1990

A 5-kW xenon ion thruster lifetest

The results of the first life test of a high power ring-cusp ion thruster are presented. A 30-cm laboratory model thruster was operated steady-state at a nominal beam power of 5 kW on xenon propellant for approximately 900 hours. This test was conducted to identify life-timing erosion modifications, and to demonstrate operation using simplified power processing. The results from this test are described including the conclusions derived from extensive post-test analyses of the thruster. Modifications to the thruster and ground support equipment, which were incorporated to solve problems identified by the lifetest, are also described.

Patterson, Michael J.↗
NASA NTRS2008

Wireless Power Transmission Options for Space Solar Power

Space Solar Power (SSP), combined with Wireless Power Transmission (WPT), offers the far-term potential to solve major energy problems on Earth. In the long term, we aspire to beam energy to Earth from geostationary Earth orbit (GEO), or even further distances in space. In the near term, we can beam power over more moderate distances, but still stretch the limits of today s technology. In recent studies, a 100 kWe-class "Power Plug" Satellite and a 10 kWe-class Lunar Polar Solar Power outpost have been considered as the first steps in using these WPT options for SSP. Our current assessments include consideration of orbits, wavelengths, and structural designs to meet commercial, civilian government, and military needs. Notional transmitter and receiver sizes are considered for use in supplying 5 to 40 MW of power. In the longer term, lunar or asteroidal material can be used. By using SSP and WPT technology for near-term missions, we gain experience needed for sound decisions in designing and developing larger systems to send power from space to Earth.

Potter, Seth↗