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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Mark 4-A DSCC telemetry system description

The DSN is undertaking a major modification of the Mark 3. The modified network described is the Mark 4-A. The DSCC portion of the DSN telemetry system is changed in two major ways as a result of the Mark 4-A DSN implementation. Two 34 meter antennas are added to each deep space communications complex (DSCC). The arraying of those antennas with the existing 64 and 34 meter antennas will provide the equivalent of two separate 64 meter antennas or two 64 meter antennas arrayed together. To accomplish this, the DSCC is modified to provide baseband combining of three 34 meter antennas and one 64 meter antenna. The telemetry system is configured to support either two deep space missions and one highly elliptical orbiter or two highly elliptical orbiters and one deep space mission. Highly elliptical orbiter missions have data rates up to 202 ksps modulated directly on the carrier.

Burt, R.↗
NASA NTRS2007

SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe

SIMBOL-X is a high energy new generation telescope covering by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays, i.e. from 0.5 to 80 keV. It is using in this field a focalizing payload which until now was used for energy below 10 keV only, via the construction of a telescope distributed on two satellites flying in formation. SIMBOL-X permits a gain of two orders of magnitude in sensibility and spatial resolution in comparison to state of the art hard X-rays instruments. The mirror satellite will be in free flight on a high elliptical orbit and will target the object to observe very precisely, thus focusing the hard X-ray emission thanks to this mirror module. At the focal point area which is situated 20 meters behind the mirror satellite, the detector satellite maintains its position on a forced orbit thanks to a radio link with the mirror satellite and a lateral displacement sensor using a beam emitted onboard the mirror satellite. This configuration is said "formation flying". The location of the detector satellite shall be very finely tuned as it carries the focal plane of this distributed telescope. To provide science measurements, the Simbol-X orbit has been chosen High elliptic (HEO), which means elliptical orbit with a high perigee altitude. Preliminary studies where made with an orbit with an altitude of the perigee of 44000km and altitude of the apogee of 253000km. The orbit was seven days ground track repeated in order to maintain a perigee pass over the Malindi ground station to download scientific telemetry. But as studies went on, difficulties in mass budget, link budget, perigee maintenance and formation flying maintenance were raised. This was mainly due to the vicinity of the Moon and its disturbing effect on the satellites orbits. Alternative orbits have been proposed in order to demonstrate the feasibility of the mission. The problematic of bringing the two satellites from their injection orbit to their operational orbit 20 m apart from each other and then maintain this configuration is very challenging. It requires theoretical development of the relative motion between two satellites in high eccentric orbit with large differential disturbance on the two bodies. This paper will present the mission analysis for the Simbol-X satellites with the complex problematic of doing formation flying in high elliptic orbit.

Gamet, Philippe↗
NASA NTRS1984

Determining highly elliptical earth orbits with VLBI and Delta-VLBI

This paper shows the feasibility of using Very Long Baseline Interferometric (VLBI) data acquired by the Deep Space Network to navigate highly elliptical earth orbiting satellites. The planned mission orbit of the Ion Release Module of the Active Magnetospheric Particle Tracer Explorers is used as a reference for developing strategies and provides the first opportunity for a possible flight demonstration with a spacecraft in a highly elliptical orbit. The navigation accuracy improvements achievable with VLBI and Delta-VLBI data types are determined for comparison with the capabilities of a reference Doppler strategy. The results show that strategies using wideband Delta-VLBI measurements taken near periapse perform best, determining apoapse position to an order of magnitude better than conventional Doppler, while also substantially reducing the required antenna support.

Frauenholz, R. B.↗
NASA NTRS1985

Interferometry Measures Elliptical Satellite Orbits

Very-long-baseline interferometry offers advantages over conventional Doppler measurements. Conference paper shows feasibility of using data from very-long-baseline interferometry (VLBI) to locate and predict motion of satellites in highly elliptical orbits about Earth. VLBI data obtained from Deep Space Network. Data not only improves navigation accuracy but also acquired with less use of worldwide network of ground stations.

Frauenholz, R. B.↗
NASA NTRS1977

Atmospheric braking to circularize an elliptical Venus orbit

The use of atmospheric drag to circularize an elliptical spacecraft orbit at Venus is analyzed parametrically for the Venus Orbital Imaging Radar Mission (VOIR) in 1983. Navigation, maneuver, and guidance requirements are discussed for the decay of a 24-hr orbit to a close circular orbit in about 30-60 days. A prototype 'Aerobrake' is described which is approximately 5 m in diameter and 25 kg in mass and which replaces a chemical retroengine of about 1300 kg in mass (delta V = 2.5 km/s) by a 700 kg in-orbit mass. The aerobrake, a light deployable Inconel sheet, shields the spacecraft from the flow and radiates the aerodynamic heating.

Mcronald, A. D.↗
NASA NTRS2000

Optical Communications Study for the Next Generation Space Telescope

The Next Generation Space Telescope (NGST), part of NASA's Origins program, is a follow on to the Hubble Space Telescope expected to provide timely new science along with answering fundamental questions. NGST is a large diameter, infrared optimized telescope with imaging and spectrographic detectors which will be used to help study the origin of galaxies. Due to the large data NGST will collect, Goddard Space Flight Center has considered the use of optical communications for data downlink. The Optical Communications Group at the Jet Propulsion Laboratory has performed a study on optical communications systems for NGST. The objective of the study was to evaluate the benefits gained through the use of optical communication technologies. Studies were performed for each of four proposed NGST orbits. The orbits considered were an elliptical orbit about the semi stable second Lagrangian point, a 1 by 3 AU elliptic orbit around the sun, a 1 AU drift orbit, and a 1 AU drift orbit at a 15 degree incline to the ecliptic plane. An appropriate optical communications system was determined for each orbit. Systems were evaluated in terms of mass, power consumption, size, and cost for each of the four proposed orbits.

Ceniceros, Juan M.↗
NASA NTRS2018

In-Flight Operation of the Dawn Ion Propulsion System Through Completion of the Final Orbit Around Dwarf Planet Ceres

The Dawn mission, part of NASA’s Discovery Program, has as its goal the scientific exploration of the two most massive main-belt objects, Vesta and Ceres. The Dawn spacecraft was launched from the Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H- 9.5 (Delta-II Heavy) rocket that placed the 1218-kg spacecraft onto an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory for the heliocentric transfer to Vesta, orbit capture at Vesta, transfer between Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, transfer between Ceres science orbits, and orbit maintenance maneuvers. Full-power thrusting from December 2007 through October 2008 was used to successfully target a Mars gravity assist flyby in February 2009 that provided an additional DV of 2.6 km/s. Deterministic thrusting for the heliocentric transfer to Vesta resumed in June 2009 and concluded with orbit capture at Vesta on July 16, 2011. From July 2011 through September 2012 the IPS was used to transfer to all the different science orbits at Vesta and to escape from Vesta orbit. Cruise for a rendezvous with Ceres began in August 2012 and completed in late December 2014. From December 2014 through June 2016 the IPS was used for transiting the spacecraft to all science orbits at Ceres including the final orbit for Dawn’s primary mission, called the low altitude mapping orbit (LAMO), a circular orbit at a mean altitude above Ceres of approximately 385 km. Dawn met or exceeded all pre-launch science requirements and Dawn's prime mission concluded on June 30, 2016. Dawn subsequently received NASA approval for two extended missions at Ceres, called XM1 and XM2. During XM1 IPS was used for orbit maintenance and to transit the spacecraft to several new, higher-altitude science orbits, ending in an elliptical orbit at a maximum altitude of approximately 38,000 km. In XM2, IPS operations included transiting the Dawn spacecraft to its final, highly elliptical orbit at Ceres ranging from 35 km perigee to 4,800 km apogee. Science data acquisition will continue in XM2 until the hydrazine is exhausted, which is expected to occur between August and October 2018. Dawn has successfully completed all science goals for both the primary and XM1 extended missions. To date the IPS has been operated for approximately 51,250 hours, consumed approximately 416 kg of xenon, and provided a delta-V of almost 11.5 km/s, a record for an on-board propulsion system. The IPS performance characteristics are close to the expected performance based on analysis and testing performed pre-launch. Dawn’s IPS continues to be fully operational as of June 2018. This paper provides an overview of Dawn’s mission objectives and the results of Dawn IPS mission operations for XM1, and XM2 through June 2018.

Rayman, Marc D.↗
NASA NTRS1986

An elliptical binary orbit model of GX 1 + 4

The X-ray source GX 1 + 4 (4U 1728-24) was observed by the high-energy X-ray spectrometer on OSO 8 for five days from September 20-24, 1978, and X-rays in the energy range 16-72 keV were analyzed. Measurements of the pulse period, pulsar angular acceleration, and luminosity of GX 1 + 4 are reported. The pulsar light curves obtained in different energy ranges are presented, and it is concluded that the period is about 220 s rather than about 110 s. The observations are combined with those reported by others, and a history of GX 1 + 4 as observed in hard X-rays is presentd. A continuous function for the change in period is inferred that suggests a 304-day periodicity. It is proposed that such a period in the spin-up could be caused by an elliptical orbit of GX 1 + 4 abouts its red giant companion.

Cutler, E. P.↗
NASA NTRS1990

Impact of Non-geostationary Orbits on PASS

The use of satellites in non-geostationary orbits (NGO) for PASS (Personal Access Satellite System) is discussed. The following subject areas are covered: (1) orbit parameters (circular and elliptical orbit characteristics); (2) link characteristics (Doppler shift, propagation loss, CONUS coverage antenna, multibeam antenna gain, and impact on link equations); (3) number of satellites required for continuous CONUS coverage (circular and elliptical orbit results); and (4) advantages and disadvantages of NGOs.

Estabrook, Polly↗
NASA NTRS1978

Hughes/GE improved NiCd cell design

Synchronous orbit and elliptical orbit life tests are used to make improvements in cell design for spacecraft application. The test increased the electrolyte volume and the surface area in cells to reduce the current density on charge and discharge.

Krause, S.↗
NASA NTRS1981

Mark 4-A DSCC telemetry system description

This system is designed as a replacement for the Mark III. Two major changes in the DSCC portion of the DSN Telemetry System are discussed: the addition of two 34 meter antennas to each DSCC; and the configuration of the telemetry system. The telemetry system is configured to support either two deep space missions and one highly elliptical orbit, or two highly elliptical orbits and one deep space mission.

Burt, R.↗
NASA NTRS1992

Advanced propulsion for LEO-Moon transport. 2: Tether configurations in the LEO-Moon system

This brief work discusses a possible application of a tether as a dynamical element in a low Earth orbit (LEO)-Moon transport system, and is a part of the Cal Space study of that transport system. To be specific, that study concentrated on the downward transport of O2 from the Moon to LEO, where it is stored for use as a rocket propellant, thus reducing Earth liftoff mass requirements by a factor of about 8. Moreover, in order to display clearly the role of advanced technology, only one novel technology was introduced at a single node in the transport system, the rest being 'conventional' rocket transport. Tethers were found useful in several different roles: hanging from platforms in lunar orbits, as supports for elevators, spinning in LEO, or spinning in a tether transport orbit, an elliptical orbit with perigee at approximately 600 km. This last use is considered here. Presented are the usefulness of the tether, nature of the tether system, the apparatus needed to support, deploy, and control it, and a discussion of needed developments.

Arnold, J. R.↗
NASA NTRS2000

New Millennium EO3

The New Millennium Program (NMP) is a NASA technology program that focuses on the validation of advanced spacecraft and instrumentation technologies in space. This program specifically seeks technologies that could significantly benefit future space and Earth science missions by enabling new science capabilities and reducing life cycle costs. These technologies must also require a validation in space to mitigate risks to the first science users, and provide cross-cutting benefits to both NASA's Earth and Space Science enterprises. The NASA Office of Earth Science (OES) directed the NMP to focus the third Earth Observing mission, E03, on innovative measurement concepts that would facilitate remote sensing observations from orbits beyond conventional low-Earth orbit (LEO). These orbits include geosynchronous orbits, highly elliptical orbits, mid-Earth and high-Earth orbits, and other unique vantage points such as L1 and L2. To maximize the input from the Earth science community, a NASA Research Announcement (NRA) was released to solicit innovative measurement concepts for this NMP flight. Because the NMP is a technology validation program, rather than a conventional science program, the NRA required that these measurement concepts employ revolutionary technologies and/or measurement strategies that will enable future science missions from orbits beyond LEO. Another requirement was that a validation in space was needed to reduce real or perceived risks of this concept to future science users. The proposals submitted in response to this NRA were peer reviewed by the NASA OES. The measurement concepts selected through this process will be summarized in this presentation. The E03 measurement concept NRA did not solicit complete mission concepts or flight hardware. Instead, the selected investigators will join integrated project formulation teams to define the mission for the demonstration of the measurement technique and participate in mission design trades and implementation planning. The teams will define and document the measurement approach, the required technologies, the validation plan, the scalability of the design to future science missions, and the infusion path for the completely validated instrument. During this project formulation phase, the specific technologies required to implement each measurement concept will be solicited through an open technology solicitation, and the technology providers will be added to the integrated teams. Once a complete candidate mission concept has been formulated for each measurement concept, these concepts will be subjected to a comprehensive review. The Associate Administrator of the OES will use the results of this review to select a single concept for the E03 flight opportunity. That mission concept will enter its implementation phase, which is expected to last for less than 36 months before launch. During this phase, and after launch, the implementation team will work with the NMP to document and disseminate the information gathered during the flight qualification testing and operations of the measurement concept and its component technologies. This information will be archived and published, where appropriate, to encourage the rapid infusion of these validated technologies into future space and Earth science missions. I

Li, Fuk K.↗
NASA NTRS2018

Mission Design for the Exploration of Ice Giants, Kuiper Belt Objects and Their Moons Using Kilopower Electric Propulsion

The exploration of Ice Giants, Kuiper Belt Objects (KBOs) and their moons pose unique challenges from a mission design standpoint. NASA is currently developing a scalable 1-10 kilowatt electric class in-space fission reactor, known as Kilopower. The focus of this paper is to investigate the applicability of Kilopower Electric Propulsion to orbiting missions to Uranus, Neptune, and Pluto. This effort is broken into two pieces for each destination. First, a broad search of interplanetary trajectories with multiple gravity assists is completed to identify a range of mission opportunities from 2025 to 2045. Second, preliminary analysis is completed to understand the accessibility of various destination orbits, including elliptical orbits around the primary body and circular orbits around the largest moons. Results suggest that orbital missions to Uranus and Neptune are feasible with reasonable time of flight. Further work is necessary to achieve similar success with Pluto missions, but preliminary results are promising.

Uranus↗
NASA NTRS1976

Mission design implications of an inclined elliptical geosynchronous orbit /International Ultraviolet Explorer/

In order to maximize the weight capability, an inclined elliptical geosynchronous orbit rather than the initially conceived circular one was selected for the International Ultraviolet Explorer (IUE), a joint NASA/ESA effort to study the ultraviolet spectra of stars, galaxies and nebulae. The design of intermediate and mission orbits satisfying the numerous mission requirements and constraints is discussed. The other areas of mission analysis included in the paper are launch window analysis, and orbit evolution and stationkeeping analysis. A significant result of the study is the manner in which statistical data, generated by a Monte Carlo simulation, were incorporated into the pre-flight mission analysis.

Dial, O. L.↗