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Results for “INTERPLANETARY SPACECRAFT”

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 181 records · Page 10
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NASA NTRS1985

Gravitational wave searches with ground tracking networks

Long-term experiments designed to search for gravitational waves (GW) have been performed with the Pioneer 10 and 11 spacecraft, and are planned for NASA's Galileo and ESA's Ulysses spacecraft. The result of a passing monochromatic GW is a sinusoidal modulation of the Doppler series that depends on the round-trip light time (RTLT) to a spacecraft and on the angle between the radiation propagation direction and the spacecraft link. Thus, an ideal experiment must have coverage and monitoring of interplanetary spacecraft during cruise that must be continuous as the earth turns to permit observation of complete three-pulse responses over the RTLT. To achieve this goal, an international 40-day Joint Tracking Experiment (JTE) is planned for the fall of 1987 for continuous tracking of the two spacecraft, when both will be near solar opposition. A diagram of the tracking geometry during the JTE and diagrams illustrating theoretical GW properties are included.

Estabrook, F. B.↗
NASA NTRSDate not supplied

Smooth Particle Hydrodynamic Code Predictions for Meteoroid Damage to Thermal Protection Systems Shielded By Composite Structures

Interplanetary spacecraft are exposed to meteoroid fluxes with characteristics far exceeding the physical simulation capabilities of test facilities for predicting the likelihood that a meteoroid will penetrate a spacecraft’s critical systems. Accurate risk predictions are crucial to ensuring that important interplanetary missions, such as sample returns, can survive years of exposure to the meteoroid environment and safely reenter the Earth’s atmosphere with their scientific cargo. In this paper, we summarize a series of meteoroid impact damage computational simulations into two types of spacecraft composite protective structures using the Smooth Particle Hydrodynamics Code. We consider the effects of both meteoric materials and non-meteoric materials on a shielded forebody thermal protection system (TPS) for an extreme entry environment and on an unshielded aftbody TPS that is similar to the material covering the space shuttle’s external tank.

Brooke Corbett↗
NASA NTRS2002

Outer planet spacecraft temperature testing and analysis

Unmanned spacecraft flown on missions to the outer planets of the solar system have included flybys, planetary orbiters, and atmospheric probes during the last three decades. The thermal design, test, and analysis approach applied to these spacecraft evolved from the passive thermal designs applied to the earlier lunar and interplanetary spacecraft. The inflight temperature data from representative sets of engineering subsystems and science instruments from a subset of these spacecraft are compared to those obtained during the ground test programs and from the prelaunch predictions. Several lessons are presented with specific recommendations for considerations for new projects to aid in the planning of cost effective temperature design, test, and analysis programs.

temperature testing planetary spacecraft Voyager G↗
NASA NTRS1984

The performance of differential VLBI delay during interplanetary cruise

Project Voyager radio metric data are used to evaluate the orbit determination abilities of several data strategies during spacecraft interplanetary cruise. Benchmark performance is established with an operational data strategy of conventional coherent doppler, coherent range, and explicitly differenced range data from two intercontinental baselines to ameliorate the low declination singularity of the doppler data. Employing a Voyager operations trajectory as a reference, the performance of the operational data strategy is compared to the performances of data strategies using differential VLBI delay data (spacecraft delay minus quasar delay) in combinations with the aforementioned conventional data types. The comparison of strategy performances indicates that high accuracy cruise orbit determination can be achieved with a data strategy employing differential VLBI delay data, where the quantity of coherent radio metric data has been greatly reduced.

Moultrie, B.↗
NASA NTRS1984

The Performance of Differential VLBI Delay During Interplanetary Cruise

Project Voyager radio metric data are used to evaluate the orbit determination utilities of several data strategies during spacecraft interplanetary cruise. Benchmark performance is established with an operational data strategy of conventional coherent Doppler, coherent range, and explicitly differenced range data from two intercontinental baselines to ameliorate the low declination singularity of the Doppler data. Employing a Voyager operations trajectory as a reference, the performance of the operational data strategy is compared to the performances of data strategies using differential VLBI delay data (spacecraft delay minus quasar delay) in combination with the aforementioned conventional data types. The comparison of strategy performances indicates that high accuracy cruise orbit determination can be achieved with a data strategy employing differential VLBI delay data, where the quantity of coherent radio metric data was reduced by over 95% with a concurrent 90% reduction in the DSN time allocated to radio metric data acquisition.

Moultrie, B.↗
NASA NTRS1995

Accuracy of wet troposphere radio path delay estimated from infrared emission

Several radio science applications require determination of the excess radio-propagation path delay caused by the Earth's atmosphere. These include very long baseline interferometry, spacecraft tracking, and potentially, detection of gravitational waves utilizing a link to a distant interplanetary spacecraft. At Ka band, the major source of variability of path delay is the fluctuations in the moisture content of the troposphere. The path delay characterization requirements for a planned gravitational wave experiment are novel and challenging. the error contribution to the phase observations due to path delay variation must be reduced by nearly two orders of magnitude over that occurring naturally on time scales of 100 to 10,000 seconds. Current approaches relying on microwave water vapor radiometry with ancillary data can deliver one order of magnitude calibration of these fluctuations, and more advanced systems are under development within the 2001-2002 time frame of the Cassini Mission to Saturn. The current work evaluates the potential for an alternative observational approach, using a ground-based Fourier transform spectrometer.

Parker, J. W.↗
NASA NTRS2008

Integration of Spacecraft Telemetry into Navigation Operations for the Cassini-Huygens Mission

The Cassini orbiter is the largest and most complex interplanetary spacecraft ever built. Since attaining orbit around Saturn in the summer of 2004, Cassini, along with its Huygens probe, have been continually improving our understanding Saturn, its satellites, its enigmatic rings system, and of the solar system. One of the hallmarks of the Cassini- Huygens Project is the close working relationship between the many teams required to operate such a sophisticated spacecraft. Their ingenuity has enabled them to find new and different ways to improve their processes during Cassini's prime 4-year orbital tour. This paper will discuss the relationship between Cassini's Navigation and Spacecraft Teams and the work required to properly configure Cassini's telemetry system for Navigation. A detailed explanation of how the Navigation Team utilizes spacecraft telemetry and analysis demonstrating the benefits will also be provided. Finally, telemetry requirements for Navigation for future missions will be addressed.

AACS↗
NASA NTRS2012

The Interplanetary Network Supplement to the Fermi GBM Catalog - An AO-2 and AO-3 Guest Investigator Project

In the first two years of operation of the Fermi GBM, the 9-spacecraft Interplanetary Network (IPN) detected 158 GBM bursts with one or two distant spacecraft, and triangulated them to annuli or error boxes. Combining the IPN and GBM localizations leads to error boxes which are up to 4 orders of magnitude smaller than those of the GBM alone. These localizations comprise the IPN supplement to the GBM catalog, and they support a wide range of scientific investigations.

Hurley, K.↗
NASA NTRS1982

Modulated Multiple Slit Camera for improved localization of gamma ray bursts

An instrument is described in which a cylindrical modulation collimator is added to one half of a Multiple Slit Camera (MSC) coded-aperture imaging system. The instrument provides gamma-ray burst positions from a single spacecraft that are as precise as the best positions from the long-baseline network of interplanetary spacecraft. The determination of fine positions is described, and the fine-position capability is shown to operate over about two-thirds of the MSC's nearly all-sky field of view. It is noted that the addition of the modulation collimator only slightly reduces the system's sensitivity and can improve the location precision for gamma-ray bursts and slower hard-X-ray transients to about 0.1 sq arcmin.

Gorenstein, P.↗
NASA NTRS1998

Interplanetary Meteoroid Model Update

The effects of the sporadic meteroid environment on interplanetary spacecraft have an inportant impact on mission design. This paper describes a reformulation of the Divine interplanetary meteroid model, called METEM, that is capable of estimating many of those effects.

interplanetary meteors meteroid model↗
NASA NTRS2009

The Applications of NASA Mission Technologies to the Greening of Human Impact

I will give an overview talk about flight software systems, robotics technologies and modeling for energy minimization as applied to vehicles and buildings infrastructures. A dominant issue in both design and operations of robotic spacecraft is the minimization of energy use. In the design and building of spacecraft increased power is acquired only at the cost of additional mass and volumes and ultimately cost. Consequently, interplanetary spacecrafts are designed to have the minimum essential power and those designs often incorporate careful timing of all power use. Operationally, the availability of power is the most influential constraint for the use of planetary surface robots, such as the Mars Exploration Rovers. The amount of driving done, the amount of science accomplished and indeed the survivability of the spacecraft itself is determined by the power available for use. For the Mars Exploration Rovers there are four tools which are used: (1) models of the rover and it s thermal and power use (2) predictive environmental models of power input and thermal environment (3) fine grained manipulation of power use (4) optimization modeling and planning tools. In this talk I will discuss possible applications of this methodology to minimizing power use on Earth, especially in buildings.

Sims, Michael H.↗
NASA NTRS2015

Cassini Attitude and Articulation Control Subsystem Fault Protection Challenges During Saturn Proximal Orbits

NASA's Cassini Spacecraft, launched on October 15th, 1997 arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended mission through 2017. As part of the final extended mission, Cassini will begin an aggressive and exciting campaign of high inclination low altitude flybys within the inner most rings of Saturn, skimming Saturn's outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, presents unique fault protection related challenges, the details of which are discussed in this paper.

Bates, David M.↗
NASA NTRS2013

Fault Protection Design and Testing for the Cassini Spacecraft in a "Mixed" Thruster Configuration

NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap from the A-branch to the B-branch RCS system. If similar degradation begins to occur on any of the B-branch thrusters, Cassini might have to assume a "mixed" thruster configuration, where a subset of both A and B branch thrusters will be designated as prime. The Cassini Fault Protection FSW was recently updated to handle this scenario. The design, implementation, and testing of this update is described in this paper.

propellant↗
NASA NTRS2010

Cassini Spacecraft In-Flight Swap to Backup Attitude Control Thrusters

NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap to the backup RCS system, the details and challenges of which are described in this paper. With some modifications, it is hoped that similar techniques and design strategies could be used to benefit other spacecraft.

Bates, David M.↗
NASA NTRS2016

Cassini Operational Sun Sensor Risk Management During Proximal Orbit Saturn Ring Plane Crossings

NASA's Cassini Spacecraft, launched on October 15th, 1997 which arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004–08), and has since been approved for a first and second extended mission through 2017. As part of the final extended missions, Cassini will begin an aggressive and exciting campaign of high inclination, low altitude flybys within the inner most rings of Saturn, skimming Saturn’s outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, requires a strategy for managing the Sun Sensor Assembly (SSA) health, the details of which are presented in this paper.

fault protection↗
NASA NTRS1997

Test Verification of the Cassini Spacecraft Dynamic Model

The Cassini spacecraft mission to Saturn will be launched in October 1997, on a Titan IV/Centaur launch vehicle. Cassini is the largest interplanetary spacecraft ever developed. Before launch approval can be obtained, a test verified finite element model of the Cassini spacecraft must be completed and approved by NASA. The correctness of this model is critical to the final verification coupled loads analysis and margin of safety assessments.

Cassini↗
NASA NTRS1989

Maintainability of unmanned planetary spacecraft - A JPL perspective

The challenge posed by the need for autonomous repair of unmanned spacecraft in unattended environments in outer space is addressed. The redundancy philosophy which forms a fundamental design driver for recent JPL interplanetary spacecraft is reviewed, and the requirements for autonomous spacecraft operations are described. Autonomous fault detection and correction is discussed, and in-flight experiences with fault correction during the VO and VGR missions are described. The lessons learned from these experiences are reviewed.

Kobele, P.↗
NASA NTRSDate not supplied

Mission Architecture for the Green Propulsion Dual Mode Mission

Current spacecraft propulsion technologies are broadly divided into chemical and electric propulsion modes, each of which has unique advantages. It is common for both systems to have a place in interplanetary spacecraft, but the size, weight, and power required to carry two separate propulsion systems is extremely limiting for small spacecraft such as CubeSats. The upcoming NASA STMD-funded Green Propulsion Dual Mode (GPDM) mission will demonstrate on-orbit a novel dual-mode propulsion system known as the GPDM Propulsion System that uses the AF-M315E/ASCENT green monopropellant to feed both a chemical 100 mN monopropellant thruster and four electrospray thrusters. GPDM will fly a 6U CubeSat in low Earth orbit and perform orbit-raising and lowering maneuvers to characterize the performance of this dual-mode propulsion technology, enabling a new generation of future interplanetary small satellite explorers. The Georgia Institute of Technology Space Systems Design Laboratory (SSDL) is conducting the design, assembly, integration, testing, and mission operations of the GPDM host spacecraft, as well as the integration of the GPDM Propulsion System payload, designed by NASA’s Marshall Spaceflight Center (MSFC). The NASA Marshall Space Flight Center is overseeing the overall GPDM project as well as specific technology development activities of the GPDM Propulsion System, while electrospray thrusters are supplied by the MIT Space Propulsion Lab, with additional components supplied by MMA Design, Blue Canyon Technologies, Quasonix, Xiphos, and Rubicon Space Systems. The GPDM spacecraft will carry the GPDM Propulsion System into orbit and use a high-power S-band radio to enable real-time operations in low Earth orbit (LEO) via the NASA Tracking and Data Relay Satellite System (TDRSS). The mission is working towards a tentative launch readiness date of August 2025, in support of launch and operations commencing in January 2026. This paper describes GPDM’s overall mission concept of operations, spacecraft overview, and subsystem breakdown.

Green Propulsion Dual Mode↗