Nuclear Electric Spacecraft for Unmanned Planetary and Interplanetary Missions
Nuclear electric spacecraft for unmanned planetary and interplanetary missions - powerplants
ELECTRIC PROPULSION↗
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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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MARINER II - AN EXAMPLE OF AN ATTITUDE STABILIZED SPACE VEHICLE
Planetary spacecraft system and subsystem design with references to the mariner ii space probe
MARINER II SPACE PROBE↗
Planetary vehicle thermal insulation systems, phase I Summary report
Tests and analyses to select materials and techniques for thermal insulation of planetary spacecraft
THERMAL INSULATION↗
Analytical techniques in planetary quarantine and spacecraft sterilization Final report
Analytical techniques and calculations in planetary quarantine and spacecraft sterilization
PLANETARY ENVIRONMENT↗
Magellan Project: Evolving enhanced operations efficiency to maximize science value
Magellan has been one of NASA's most successful spacecraft, returning more science data than all planetary spacecraft combined. The Magellan Spacecraft Team (SCT) has maximized the science return with innovative operational techniques to overcome anomalies and to perform activities for which the spacecraft was not designed. Commanding the spacecraft was originally time consuming because the standard development process was envisioned as manual tasks. The Program understood that reducing mission operations costs were essential for an extended mission. Management created an environment which encouraged automation of routine tasks, allowing staff reduction while maximizing the science data returned. Data analysis and trending, command preparation, and command reviews are some of the tasks that were automated. The SCT has accommodated personnel reductions by improving operations efficiency while returning the maximum science data possible.
Cheuvront, Allan R.↗
Planned In-Space Electric Propulsion Experiments
Ion Propulsion provides an order of magnitude improvement, relative to chemical on-board propulsion systems, of specific impulse at the cost of a relatively small increase in propulsion system dry mass. For civilian space craft, ion propulsion technology provides the potential for increased performance and reduced cost for planetary spacecraft and for large satellites in geostationary orbit. For military applications ion propulsion offers significant benefits for station keeping and repositioning satellites in geostationary orbit. NASA has begun to validate ion propulsion technology for applications to which 2.5 kW to 5.0 kW ion thrusters would be appropriate. NASA's validation program, called NSTAR (NASA SEP Technology Application Readiness), consists of two major elements: a ground test element and an in-space experiment. The Ground Test Element will validate the life, integrability, and performance of low-power ion propulsion. The In-Space Element will demonstrate the ability to integrate and fly an ion propulsion system. As an experiment, it will measure the interactions between the ion propulsion system, the host spacecraft, and the surrounding space plasma; and it will provide a quantitative assessment of the ability of ground testing to replicate the in-space performance of ion thrusters. By involving industry in this program, a commercial source for this technology will be assured. Further, the successful completion of the NSTAR validation program will stimulate commercial and government (both civilian and military) uses of this technology.
ion propulsion planetary spacecraft geostationary ↗
Segmented Ion Engine Operation and Performance
The continuing trend toward smaller and smaller planetary spacecraft to enable the use of smaller, less expensive launch vehicles has motivated an examination of new approaches to reduce the size and mass of xenon ion propulsion systems for these new spacecraft. A system is proposed which is based on the use of a single 4x15-cm segmented ion thruster operated from a single internally redundant power processing unit. An engine input power throttling range of 380 to 4640 W is projected. The design and operation over a power range of 600 to 2400 W of a laboratory model segmented ion engine equipped with carbon-carbon grids is presented. There appear to be no problems associated with interactions with multiple ion sources operating from a single set of high voltage power supplies, neutralization of multiple ion sources from a single centrally located neutralizer, or operation of flat, thin carbon-carbon grids.
ion↗
Planning, evaluation, and analytical studies in planetary quarantine and spacecraft sterilization Quarterly progress report
Planetary quarantine flight regulations and information system, microbe release probability, heat sterilization cycles, organic synthesis and contamination factors, Mars landing microbes
Source record↗
Spacecraft Radio Scintillation and Solar System Exploration
When a wave propagates through a turbulent medium, scattering by the random refractive index inhomogeneities can lead to a wide variety of phenomena that have been the subject of extensive study. The observed scattering effects include amplitude or intensity scintillation, phase scintillation, angular broadening, and spectral broadening, among others. In this paper, I will refer to these scattering effects collectively as scintillation. Although the most familiar example is probably the twinkling of stars (light wave intensity scintillation by turbulence in the Earth's atmosphere), scintillation has been encountered and investigated in such diverse fields as ionospheric physics, oceanography, radio astronomy, and radio and optical communications. Ever since planetary spacecraft began exploring the solar system, scintillation has appeared during the propagation of spacecraft radio signals through planetary atmospheres, planetary ionospheres, and the solar wind. Early studies of these phenomena were motivated by the potential adverse effects on communications and navigation, and on experiments that use the radio link to conduct scientific investigations. Examples of the latter are radio occultation measurements (described below) of planetary atmospheres to deduce temperature profiles, and the search for gravitational waves. However,these concerns soon gave way to the emergence of spacecraft radio scintillation as a new scientific tool for exploring small-scale dynamics in planetary atmospheres and structure in the solar wind, complementing in situ and other remote sensing spacecraft measurements, as well as scintillation measurements using natural (celestial) radio sources. The purpose of this paper is to briefly describe and review the solar system spacecraft radio scintillation observations, to summarize the salient features of wave propagation analyses employed in interpreting them, to underscore the unique remote sensing capabilities and scientific relevance of the scintillation measurements, and to highlight some of the scientific results obtained to date. Special emphasis is placed on comparing the remote sensing features of planetary and terrestrial scintillation measurements, and on contrasting spacecraft and natural radio source scintillation measurements. I will first discuss planetary atmospheres and ionospheres, and then the solar wind.
Woo, Richard↗
Future spacecraft propulsion
Propulsion requirements for launch vehicles, upper stages, satellites and platforms, and planetary spacecraft are described from a functional perspective and compared on an energy basis. Mission velocity requirements for a range of missions are presented. A simple model relating optimum exhaust velocity and maximum system delta-V as a function of system-specific energy is developed, which provides insight into the relationship between system performance and various power and propulsion subsystem characteristics. Based on this model, various advanced propulsion options, e.g., the solid-core nuclear rocket and nuclear electric propulsion, are evaluated, and the implications of this analysis for propulsion and power system technology development programs are discussed. The objective of this paper is to provide an overview of future propulsion requirements for the nonspecialist.
Garrison, P. W.↗
Virtual Energetic Particle Observatory (VEPO)
The Virtual Energetic Particle Observatory (VEPO) focuses on improved discovery, access, and usability of heliospheric energetic particle and ancillary data products from selected spacecraft and sub-orbital instruments of the heliophysics data environment. The energy range of interest extends over the full range of particle acceleration from keV energies of suprathermal seed particles to GeV energies of galactic cosmic ray particles. Present spatial coverage is for operational and legacy spacecraft operating from the inner to the outer heliosphere, e.g. from measurements by the two Helios spacecraft to 0.3 AU to the inner heliosheath region now being traversed by the two Voyager spacecraft. This coverage will eventually be extended inward to ten solar radii by the planned NASA solar probe mission and at the same time beyond the heliopause into the outer heliosheath by continued Voyager operations. The geospace fleet of spacecraft providing near-Earth interplanetary measurements, selected magnetospheric spacecraft providing direct measurements of penetrating interplanetary energetic particles, and interplanetary cruise measurements from planetary spacecraft missions further extend VEPO resources to the domain of geospace and planetary interactions. Ground-based (e.g., neutron monitor) and high-altitude suborbital measurements can expand coverage to the highest energies of galactic cosmic rays affected by heliospheric interaction and of solar energetic particles. Science applications include investigation of solar flare and coronal mass ejection events. acceleration and transport of interplanetary particles within the inner heliosphere, cosmic ray interactions with planetary surfaces and atmospheres, sources of suprathermal and anomalous cosmic ray ions in the outer heliosphere, and solar cycle modulation of galactic cosmic rays. Robotic and human exploration, and eventual habitation, of planetary and space environments beyond the Earth require knowledge of radiation hazards informed by VEPO data resources. The VEPO project has completed the first year of work to define science requirements, to document and register selected data products in SPASE format while evolving SPASE for increased applicability to VEPO data, and to support enhanced discovery and access for these products through the evolving data query and middleware system of the Virtual Heliospheric Observatory (VHO). The VEPO team operates as a heliophysics focus group for energetic particle data resources in partnership with VHO and also leverages existing data services of NASA's Space Physics Data Facility. We invite comments from the U.S. and international data provider and user communities on review of the current VEPO/VHO user interface, on directions for future evolution of VEPO and supporting data systems including VHO and SPDF, and on relations to other elements of the heliophysics virtual observatory environment.
Cooper, John F.↗
NASA Announces Spacecraft Decontamination Procedures
The National Aeronautics and Space Administration has announced procedures for the sterilization of planetary spacecraft and revised the procedures for the decontamination of unmanned lunar landers.
DECONTAMINATION↗
Design guide for low cost standardized payloads, volume 2
Sixteen engineering approaches to low cost standardized payloads in spacecraft are presented. Standard earth observatory satellite, standard U.S. domestic communication satellite, planetary spacecraft subsystems, standard spacecraft, and cluster spacecraft are reviewed.
Source record↗
Mars Aerobraking Spacecraft State Estimation by Processing Inertial Measurement Unit Data
Aerobraking is an efficient technique for orbit adjustment of planetary spacecraft, such as Magellan (Venus), Mars Global Surveyor, and Mars Odyssey. Determination of the vehicle state during the aerobraking phase has conventionally been performed using only radiometric tracking data prior to and following the atmospheric drag pass. This approach is sufficiently accurate and timely to meet current mission operational requirements; however, it is expensive in terms of ground support and leads to delayed results because ofthe need for post-drag pass data. This research presents a new approach to estimation of the vehicle state during the atmospheric pass that sequentially incorporates observations from an Inertial Measurement Unit (IMU) and models of the vehicle and environment. The approach, called Inertial Measurements for Aerobraking Navigation (IMAN), is shown to perform at a level comparable to the conventional methods in terms of navigation accuracy and superior to them in terms of availability of the results immediately after completion ofthe pass. Furthermore, the research shows that IMAN can be used to reliably predict subsequent periapsis times and locations over all aerobraking regimes. IMAN also yields accurate peak dynamic pressure and heating rates, critical for a successful corridor control strategy, comparable to navigation team reconstructed values. This research also provides the first instance of the utilization of the Unscented Kalman Filter for the purpose of estimating an actual spacecraft trajectory arc about another planet.
Unscented Kalman Filter↗
The Voyager spacecraft system design
The Voyager spacecraft represents the state-of-the-art in proven long-life planetary spacecraft. Like its predecessors, the Voyager system design reflects the influence of mission and science requirements, lifetime considerations, environmental factors, technology readiness, hardware availability, and hardware cost. This paper presents the Voyager hardware and software system designs within the context of these design drivers. Major departures from the 'baseline design' are discussed revealing the underlying factors that shaped the final design. Finally, with the benefit of 5 years of test and inflight operational experience, a critical assessment of the design and design methods is made and suggestions are offered to improve similar future efforts.
Jones, C. P.↗
The role of power integrated circuits in lightweight spacecraft
This paper will present definitions for smart power and power integrated circuits and show how, for a typical planetary spacecraft power system, a 37 percent reduction in mass, 89 percent reduction in parts and a 50 percent reduction in volume can be attained. Also discussed are the technology needs for isolation, monolithic current sensing, and high efficiency switching necessary to enable monolithic power structures, as well as various applications of power integrated circuits. A specific example will verify the projected reductions expected when power integrated circuits are implemented in future spacecraft designs. In conclusion, power-integrated circuits can impact the overall design of the spacecraft in all subsystems, not just the power sybsystem.
Klein, John W.↗
Autonomy metrics
Space missions are currently being designed and developed to rely on increased spacecraft autonomy in order to achieve lower cost operations and to support the fleets of planetary spacecraft with limited deep space network resources. In relation to this, metrics are presented which quantitatively define spacecraft autonomy and will be used to: set measurable autonomy goals for future missions; evaluate and compare the benefits between competing automation technologies, and to compare autonomy between missions. The metrics measure the degree to which spacecraft and space mission designs lead to: longer periods of no-track; shorter track periods; reduced ground-orbit communications, and smaller operations workforces. The results of a survey applying these metrics to historic missions and to planned future missions are reported on, illustrating the differences between the autonomy achieved by previous missions and that predicted for future missions.
Carraway, John B.↗
Curating NASA's Astromaterials Collections: Past, Present, and Future
Planning for the curation of samples from future sample return missions must begin during the initial planning stages of a mission. Waiting until the samples have been returned to Earth, or even when you begin to physically build the spacecraft is too late. A lack of proper planning could lead to irreversible contamination of the samples, which in turn would compromise the scientific integrity of the mission. For example, even though the Apollo missions first returned samples in 1969, planning for the curation facility began in the early 1960s, and construction of the Lunar Receiving Laboratory was completed in 1967. In addition to designing the receiving facility and laboratory that the samples will be characterized and stored in, there are many aspects of contamination that must be addressed during the planning and building of the spacecraft: planetary protection (both outbound and inbound); cataloging, documenting, and preserving the materials used to build spacecraft (also known as coupons); near real-time monitoring of the environment in which the spacecraft is being built using witness plates for critical aspects of contamination (known as contamination control); and long term monitoring and preservation of the environment in which the spacecraft is being built for most aspects of potential contamination through the use of witness plates (known as contamination knowledge). The OSIRIS REx asteroid sample return mission, currently being built, is dealing with all of these aspects of contamination in order to ensure they return the best preserved sample possible. Coupons and witness plates from OSIRIS REx are currently being studied and stored (for future studies) at the Johnson Space Center. Similarly, planning for the clean room facility at Johnson Space Center to house the OSIRIS-REx samples is well advanced, and construction of the facility should begin in early 2017 (despite a nominal 2023 return date for OSIRIS-REx samples). Similar development is being done, in concert with JAXA, for the return of Hayabusa 2 samples (nominally in 2020). We are also actively developing advanced techniques like cold curation and organically clean curation in anticipation of future sample return missions such as comet nucleus sample return and Mars sample return.
Zeigler, Ryan↗