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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Electromagnetic deep-probing (100-1000 kms) of the Earth's interior from artificial satellites: Constraints on the regional emplacement of crustal resources

A spherical harmonic analysis program is being tested which takes magnetic data in universal time from a set of arbitrarily space observatories and calculates a value for the instantaneous magnetic field at any point on the globe. The calculation is done as a least mean-squares value fit to a set of spherical harmonics up to any desired order. The program accepts as a set of input the orbit position of a satellite coordinates it with ground-based magnetic data for a given time. The output is a predicted time series for the magnetic field on the Earth's surface at the (r, theta) position directly under the hypothetically orbiting satellite for the duration of the time period of the input data set. By tracking the surface magnetic field beneath the satellite, narrow-band averages crosspowers between the spatially coordinated satellite and the ground-based data sets are computed. These crosspowers are used to calculate field transfer coefficients with minimum noise distortion. The application of this technique to calculating the vector response function W is discussed.

Hermance, J. F.↗
DOE OSTI2026

Using Gravitational Lensing to Probe for Candidate Quintessential Galaxies in the Epoch of Reionization

Abstract Understanding the properties of the first generation of galaxies is an ongoing challenge in observational astrophysics. James Webb Space Telescope deep-field observations have led to the identification of large numbers of galaxies within the Epoch of Reionization (EoR); however, it remains observationally challenging to study the detailed properties of the most numerous, faint high- z galaxies without strong gravitational lensing. To this end, we present five m AB ≃ 24 galaxies, all projected behind the cores of massive clusters where high lensing magnifications significantly (≳1.5 mag) boost their observed brightness. These galaxies are each characterized by a drop-off in their spectra between the near-IR and optical wavelengths, suggesting the presence of a Lyman break at z > 6. The bright sources enable precise dropout color constraints. We combine the dropout data with follow-up imaging to constrain continuum slopes redward of their breaks. Using the open-source spectral energy distribution modeling software Prospector , we characterize two of these galaxies as probable high- z ( z ∼ 6.5–7) and three as probable low- z ( z ∼ 2) sources, demonstrating that for very bright ( m AB < 24) dropout candidates even limited photometric data have good power to distinguish between high- z galaxies and red or dusty low- z galaxies. The two candidate high- z dropouts are comparably bright to the brightest galaxies identified at such redshifts in deep fields, but due to lensing magnifications are intrinsically fainter by at least 1.5 mag. If confirmed, these galaxies represent exciting laboratories for performing detailed follow-up studies of galaxy properties within the EoR.

Roberson, Joshua [University of Cincinnati] (ORCID↗
NASA NTRS1980

Planetary radar

The radar astronomy activities supported by the Deep Space Network are reported. The high power S- and X-band radar transmitters at the Goldstone 64 meter station were used for a radar probe of Mars during January, February, and March 1980, which was designed to provide range and Doppler data derived from signals reflected from the Martian surface, taking advantage of the planet's nearness during opposition.

Taylor, R. M.↗
NASA NTRS1980

Pioneer Venus Overview

A Pioneer Venus Overview is discussed. Pioneer Venus consists of two basic spacecraft: Orbiter and Multiprobe. The latter was separated into five separate vehicles near Venus. These were the probe transporter (called the Bus), a large atmospheric entry probe (dubbed Sounder) and three identical smaller probes (called North , Day, and Night in accordance with their entry locations). At Venus all six spacecraft communicated directly back to the Earth-based Deep Space Network (DSN) and, in the case of the Multiprobe mission, to two special receiving sites near Guam and Santiago (Chile). At the time this Special Issue was submitted for publication the nominal mission was complete and the Orbiter was continuing into an extended mission phase. It appears so that sufficient fuel remains to permit full operation through calendar year 1980, at least. The scientific payload, Principle Investigator, and his affiliation are listed for each Pioneer Venus spacecraft. This special issue is primarily devoted to short descriptions of the instruments listed with the exception of the Orbitor Cloud Photopolarimeter. Detailed instrument descriptions for this experiment have been published. Before proceeding with descriptions of the individual instruments, four special archival-type reports are included. The first deals with spacecraft design and operation. The Pioneer Venus spacecraft were unique and very special design features and operational modes needed to be incorporated. These are summarized therein. It should be noted that neither the scientific objectives nor the scientific results of the Pioneer Venus program are described or discussed in detail. The objectives have been published elsewhere.

Colin, Lawrence↗
NASA NTRS2023

Testing the Gravitational Redshift With an Inner Solar System Probe: the Veritas Case

The NASA Discovery-class mission VERITAS, selected in June 2021, will be launched towards Venus after 2027. In addition to the science instrumentation that will build global foundational geophysical datasets, VERITAS proposed to conduct a technology demonstration for the Deep Space Atomic Clock (DSAC-2). A first DSAC successfully operated in low-Earth orbit for more than two years, demonstrated the trapped ion atomic clock technology, and established a new level of performance for clocks in space. DSAC-2 would have further improvements in size, power, and performance. It would host a 1× 10 -13 grade USO to produce a frequency output with short-term stability of less than 2× 10 -13 /√ τ (where τ is the averaging time).However, due to funding shortfalls, DSAC-2, had to be canceled. The initially foreseen presence of an atomic clock on board the probe, however, raised the question whether this kind of instrumentation could be useful not only for navigation and time transfer but also for fundamental physics tests. In this work, we consider the DSAC-2 atomic clock and VERITAS mission as a specific example to measure possible discrepancies in the redshift predicted by General Relativity by using an atomic clock onboard an interplanetary spacecraft. In particular we investigate the possibility of measuring possible violations of the Local Lorentz Invariance and Local Position Invariance principles. We perform accurate simulations of the experiment during the VERITAS cruise phase. We consider different parametrizations of the possible violations of the General Relativity, different operational conditions, and several different assumptions on the expected measurement performance. We show that DSAC-2 onboard VERITAS would provide new and improved constraints with respect to the current knowledge. Our analysis shows the scientific value of atomic clocks like DSAC-2 hosted onboard interplanetary spacecraft.

Fabrizio De Marchi↗
NASA NTRS1998

Optical Communication Subsystem for the X200 Series of Planetary Missions

NASA has started a major new Advanced Deep Space System Development (a.k.a x2000) Program at JPL. The objective of this program is to develop and space-qualify (in a total system environment) advanced, cutting-edge technologies for the next generation of deep-space exploration missions.

Optical Communication Planetary Missions Fire and ↗
NASA NTRS2012

Development of the Optical Communications Telescope Laboratory: A Laser Communications Relay Demonstration Ground Station

The Laser Communications Relay Demonstration (LCRD) project will demonstrate high bandwidth space to ground bi-directional optical communications links between a geosynchronous satellite and two LCRD optical ground stations located in the southwestern United States. The project plans to operate for two years with a possible extension to five. Objectives of the demonstration include the development of operational strategies to prototype optical link and relay services for the next generation tracking and data relay satellites. Key technologies to be demonstrated include adaptive optics to correct for clear air turbulence-induced wave front aberrations on the downlink, and advanced networking concepts for assured and automated data delivery. Expanded link availability will be demonstrated by supporting operations at small sun-Earth-probe angles. Planned optical modulation formats support future concepts of near-Earth satellite user services to a maximum of 1.244 Gb/s differential phase shift keying modulation and pulse position modulations formats for deep space links at data rates up to 311 Mb/s. Atmospheric monitoring instruments that will characterize the optical channel during the link include a sun photometer to measure atmospheric transmittance, a solar scintillometer, and a cloud camera to measure the line of sight cloud cover. This paper describes the planned development of the JPL optical ground station.

optical commuication↗
NASA NTRS2000

Transportation System Options For The Interstellar Probe Mission

NASA is considering a mission to explore near-interstellar space early in the next decade as the first step toward a vigorous interstellar exploration program. A key enabling technology for such an ambitious science and exploration effort is the development of propulsion systems capable of providing fast trip times. Advanced propulsion technologies that might support an interstellar precursor mission early in the next century include some combination of solar sails, nuclear electric propulsion systems, and aerogravity assists. For years, the scientific community has been interested in the development of solar sail technology to support exploration of the inner and outer planets. Progress in thin-film technology and the development of technologies that may enable the remote assembly of lar2e sails in space are only now maturing to the point where ambitious interstellar precursor missions can be considered. Electric propulsion is now being demonstrated for planetary exploration by the Deep Space I mission. The primary issues for it's adaptation to interstellar precursor applications include the nuclear reactor that would be required and the engine lifetime. A propulsion system concept for the proposed Interstellar Probe mission will be described for each.

Johnson, Charles Les↗
NASA NTRS2015

Error Budgets for the Exoplanet Starshade (exo-s) Probe-Class Mission Study

Exo-S is a probe-class mission study that includes the Dedicated mission, a 30 millimeters starshade co-launched with a 1.1 millimeter commercial telescope in an Earth-leading deep-space orbit, and the Rendezvous mission, a 34 millimeter starshade intended to work with a 2.4 millimeters telescope in an Earth-Sun L2 orbit. A third design, referred to as the Rendezvous Earth Finder mission, is based on a 40 millimeter starshade and is currently under study. This paper presents error budgets for the detection of Earth-like planets with each of these missions. The budgets include manufacture and deployment tolerances, the allowed thermal fluctuations and dynamic motions, formation flying alignment requirements, surface and edge reflectivity requirements, and the allowed transmission due to micrometeoroid damage.

high-contrast imaging↗
NASA NTRS1962

MARINER 2 FLIGHT TO VENUS

The trajectory analysis behind this spacecraft's history-making flight to Venus, which reaches the high point of flyby on December 14, will become a fundamental operation for future deep-space flights.

TRACKING↗
NASA NTRS1993

Clementine 2: a Double Asteroid Flyby and Impactor Mission

Recently JPL was asked by SDIO to analyze and develop a preliminary design for a deep-space mission to fly by two near-Earth asteroids, Eros and Toutatis. As a part of this mission, JPL was also asked to assess the feasibility of deploying a probe on approach to impact Toutatis. This mission is a candidate for SDIO's Clementine 2. SDIO's motivations were to provide further demonstrations of precision, autonomous navigation for controlling the flight paths of both a spacecraft and a probe. NASA's interest in this mission is driven by the opportunity to obtain the first close-up images and other scientific measurements from a spacecraft of two important near-Earth objects. For Toutatis this is especially important since it was observed and imaged extensively just last Dec. using Earth-based radar; Clementine 2 will provide the opportunity to corroborate the radar data and validate the ultimate potential of the radar technique. Scientifically, the probe impact at Toutatis will allow the acquisition of data pertaining to the dynamic strength of surface material and data on the properties of the regolith and on stratification below the surface, and will potentially allow the measurement of thermal diffusivity between the interior and the surface. These determinations will be accomplished by means of high-resolution imagery of the impact crater and its surroundings in visible, ultraviolet, and infrared wave bands from the spacecraft flying by some 30 min. after the probe strike. In addition, if the spacecraft can be equipped with a lightweight mass spectrometer and dust analyzer, the potential also exists to measure the particle sizes and distribution and the composition of the eject a cloud. This mission is planned to be launched in Jul. 1995, with the Eros encounter on 13 Mar. 1996, and the Toutatis flyby on 4 Oct. 1996, some 440 days after launch.

Boain, R. J.↗
NASA NTRS2013

Emission-line Galaxies from the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (Pears) Grism Survey. II. The Complete Sample

We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0 < z < 1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 Hα, [O III], and/or [O II] emission lines in the PEARS sample of 906 galaxies to a limiting flux of ~10 -18(exp) erg s -1(exp) cm -2(exp). The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M * ≥ 10 9(exp) M ☉ decreases by an order of magnitude at z ≤ 0.5 relative to the number at 0.5 < z < 0.9, supporting the argument of galaxy downsizing.

Hubble↗
NASA NTRS2006

NASA's 2004 In-Space Propulsion Refocus Studies for New Frontiers Class Missions

The New Frontiers (NF) program is designed to provide opportunities to fulfill the science objectives for top priority, medium class missions identified in the Decadal Solar System Exploration Survey. This paper assesses the applicability of the In-Space Propulsion s (ISP) Solar Electric Propulsion (SEP) technologies for representative NF class missions that include a Jupiter Polar Orbiter with Probes (JPOP), Comet Surface Sample Return (CSSR), and two different Titan missions. The SEP technologies evaluated include the 7-kW, 4,100-second NASA's Evolutionary Xenon Thruster (NEXT), the 3-kW, 2,700-second Hall thruster, and two different NASA Solar Electric Propulsion Technology Readiness (NSTAR) thrusters that are variants of the Deep Space 1 (DS1) thruster. One type of NSTAR, a 2.6-kW, 3,100-second thruster, will be the primary propulsion system for the DAWN mission that is scheduled to launch in 2006; the other is an "enhanced", higher power variant (3.8-kW, 4,100-second) and is so-called because it uses NEXT system components such as the NEXT power processing unit (PPU). The results show that SEP is applicable for the CSSR mission and a Titan Lander mission. In addition, NEXT has improved its applicability for these types of missions by modifying its thruster performance relative to its performance at the beginning of this study.

Witzberger, Kevin E.↗
NASA NTRS1985

On the trail of Comet G-Z

The International Cometary Explorer (ICE) is to investigate the magnetic and electric fields, plasmas, and particles in the Comet Giacobini-Zinner (G-Z) and to study its interaction with solar wind. The ICE can pass through the comet only once and it will take 90 minutes to cross from one side of the tail to the other. Since the Comet G-Z often changes its orbit due to nongravitational forces changing its direction and velocity, ICE's position needs to be adjusted. The probe is aimed 10,000 km from the nucleus in order to be provided the best passage through the Comet G-Z. The 64-meter dishes of JPL's Deep-Space Network (DSN) will receive data transmitted on two adjacent S-band frequencies at the rate of 1024 bits per second. Also NASA has arranged for the radio telescope at Arecibo to record the transmission. The Japanese 64-meter tracking antenna at Usada, equipped with an ultrasensitive receiver for one ICE frequency, will provide pre-encounter and post-encounter tracking. The ICE data may provide information about the dust tail in the Comet G-Z which could be compared to previous research.

Maran, S. P.↗
DOE OSTI2025

QUPITER -- Space Quantum Sensors for Jovian-Bound Dark Matter

We propose utilizing space quantum sensors to detect ultralight dark matter (ULDM) bound to planetary bodies, focusing on Jupiter as the heaviest planet in the solar system. Leveraging Jupiter's deep gravitational potential and the wealth of experience from numerous successful missions, we present strong sensitivity projections on the mass and couplings of scalar ULDM. Future space missions offer unique opportunities to probe the ULDM interactions using quantum sensors, including superconducting quantum interference device (SQUID) magnetometers. By measuring dark matter-induced magnetic field oscillations, we expect to achieve sensitivity orders of magnitude beyond the terrestrial probes and significantly improve detection prospects of theoretically motivated ULDM candidates.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS2012

Self-Nulling Lock-in Detection Electronics for Capacitance Probe Electrometer

A multi-channel electrometer voltmeter that employs self-nulling lock-in detection electronics in conjunction with a mechanical resonator with noncontact voltage sensing electrodes has been developed for space-based measurement of an Internal Electrostatic Discharge Monitor (IESDM). The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. Use of an AC-coupled lock-in amplifier with closed-loop sense-signal nulling via generation of an active guard-driving feedback voltage provides the resolution, accuracy, linearity and stability needed for long-term space-based measurement of the IESDM. This implementation relies on adjusting the feedback voltage to drive the sense current received from the resonator s variable-capacitance-probe voltage transducer to approximately zero, as limited by the signal-to-noise performance of the loop electronics. The magnitude of the sense current is proportional to the difference between the input voltage being measured and the feedback voltage, which matches the input voltage when the sense current is zero. High signal-to-noise-ratio (SNR) is achieved by synchronous detection of the sense signal using the correlated reference signal derived from the oscillator circuit that drives the mechanical resonator. The magnitude of the feedback voltage, while the loop is in a settled state with essentially zero sense current, is an accurate estimate of the input voltage being measured. This technique has many beneficial attributes including immunity to drift, high linearity, high SNR from synchronous detection of a single-frequency carrier selected to avoid potentially noisy 1/f low-frequency spectrum of the signal-chain electronics, and high accuracy provided through the benefits of a driven shield encasing the capacitance- probe transducer and guarded input triaxial lead-in. Measurements obtained from a 2- channel prototype electrometer have demonstrated good accuracy (|error| < 0.2 V) and high stability. Twenty-four-hour tests have been performed with virtually no drift. Additionally, 5,500 repeated one-second measurements of 100 V input were shown to be approximately normally distributed with a standard deviation of 140 mV.

Blaes, Brent R.↗
NASA NTRS1998

Subsurface Structure in the Martian Polar Layered Deposits: The Deep Space 2 Impact Accelerometry Experiment

While primarily a technology demonstration mission, the New Millenium Mars Microprobes (also known as Deep Space 2, or simply DS2)will also provide the first in situ science measurements of the martian subsurface. The DS2 impact accelerometry experiment will provide both engineering data about the depth of probe emplacement and science data about the physical nature of the subsurface at the probes' landing sites. Little is known about the detailed physical properties or small-scale vertical structure of the subsurface at the DS2 landing site in the southern martian polar layered deposits. Imaging data from the Viking Orbiters and Mars Global Surveyor reveal alternating bands of light and dark material in this region with thicknesses at least as small as the limit of resolution, about 10 m. The overall composition of these layers is poorly constrained, but generally thought to be a mixture of dust and ice with the layers being caused by variations in the dust/ice ratio, or perhaps by dust deposits of different densities. Low thermal inertias in the region suggest that the top few centimeters of the surface are composed of a mantling of fine-grained dust. However, 3.5-cm radar returns indicate that the maximum depth of this dust is not greater than a few tens of centimeters. Thermal models generally agree that, while the layered deposits do provide a potential near-surface reservoir for ice, the uppermost few centimeters to meters in these regions are likely to be ice-free because of sublimation losses. Finally, while it is generally agreed that the layered deposits are the product of variations in the martian climate, no direct correlation has been made between band sequences and specific climate changes. Our intention is to shed light on some of these questions about the martian polar layered deposits by using the DS2 accelerometry experiment to determine the physical nature of the layered deposits, and to detect the presence of any subsurface layering of dust, ice, and/or rock. In the process, we will also determine the final resting depth of the two microprobes, an important parameter in the interpretation of other DS2 experiments.

Moersch, J. E.↗
NASA NTRS2000

Dynamic Capability of an Operating Stirling Convertor

The NASA John H. Glenn Research Center and the US Department of Energy are currently developing a Stirling convertor for use as an advanced spacecraft power system for future NASA deep-space missions. NASA Headquarters has recently identified the Stirling technology generator for potential use as the spacecraft power system for two of NASA's new missions, the Europa Orbiter and the Solar Probe missions (planned for launch in 2006 and 2007 respectively). As part of the development of this power system, a Stirling Technology Demonstration Convertor was vibration tested at NASA John H. Glenn Research Center to verify its survivability and capability of withstanding the harsh dynamic environment typically seen by the spacecraft when it is launched by an expendable launch vehicle. The Technology Demonstration Convertor was fully operational (producing power) during the random vibration testing. The output power of the convertor and other convertor performance indicators were measured during the testing, and these results are discussed in this paper. Numerous accelerometers and force gauges also were used to provide information on the dynamic characteristics of the Technology Demonstration Convertor and as an indication of any possible damage due to the vibration. These measurements will also be discussed in this paper. The vibration testing of the Stirling Technology Demonstration Convertor was extremely successful. The Technology Demonstration Convertor survived all its vibration testing with no structural damage or functional performance degradation. As a result of this testing, the Stirling convertor's capability to withstand vibration has been demonstrated, enabling its usage in future spacecraft power systems.

Goodnight, Thomas W.↗