Exploration Of Saturn Research Articles

Optimum design of nuclear electric propulsion spacecraft for deep space exploration

Future space exploration is now focused on new field-deep space planets. Deep space exploration and the development and utilization of resources are inestimable strategic significance for the country to seize the initiative and command heights of deep space exploration. Nuclear electric propulsion (NEP) systems convert heat from the fission reactor to electrical power and then use the electrical power to produce thrust. Compared with traditional propulsion technology, the NEP system with variable Isp can be used for several applications. The NEP spacecraft is more suitable for deep space exploration missions due to the advantages of high specific impulse, high power, and long life. This paper analyzes the relationship between the transfer travel time, specific mass, power, and payload ratio of the NEP spacecraft through simple performance models. Use the mass optimization and specific mass optimization models based on the NEP system composition and small thrust orbit theory to maximize the payload ratio for a given transfer time and technological characteristics. Finally, applied this NEP model to discuss the feasibility of Mars, Jupiter, and Saturn transfer missions and compared it with the Tianwen-1, Juno, and Cassini–Huygens spacecraft, respectively. Results show that when the NEP spacecraft specific mass reaches 4.77 kg/kW, the Earth–Mars transfer time can be changed to 331.31 days, the payload increases to 1650 kg, the transfer time for Jupiter and Saturn mission would be shorted to 661.31 days and 1131.31 days, the corresponding payload significantly increases which achieved to 1270 kg and 2981 kg. The nuclear electric propulsion spacecraft dramatically improves the detection capability of the spacecraft and provides a reference for the feasibility demonstration and subsequent design of the deep space and the extrasolar planet exploration.

Titan aerogravity-assist maneuvers for Saturn/Enceladus missions

Mission analysis using aerogravity-assist (AGA) maneuver at Titan is presented in this paper. Considering Saturn arrival, Titan encounter, and different post-AGA orbits, the analysis uses vector diagrams to illustrate the relations among all conditions as well as design constraints. The analysis focuses on Enceladus mission concept and also present a summary result for Cassini-type Saturn system missions. Turn angles using AGA maneuver at Titan are quantified via numerical simulation, showing that 25-deg AGA turn angles are achievable with a Titan inbound excess velocity (V∞, IN) of 10–20 km/s. Results show that for an Enceladus mission, V∞, IN of 10 km/s is the minimum velocity required for AGA maneuver to achieve an outbound transfer orbit directly to Enceladus; the corresponding peak g-load is less than 6 g, peak heat rate less than 200 W/cm2, and total heat load of around 25 kJ/cm2. For a Cassini-type Saturn mission, a minimum V∞, IN of 5 km/s can be used for Titan AGA. The results showed are for V∞, IN of 6 km/s; and the corresponding peak g-load, peak heat rate, and total heat load are 1.5 g, 20 W/cm2, and 5 kJ/cm2 respectively.

Titan as Revealed by the Cassini Radar

Titan was a mostly unknown world prior to the Cassini spacecraft’s arrival in July 2004. We review the major scientific advances made by Cassini’s Titan Radar Mapper (RADAR) during 13 years of Cassini’s exploration of Saturn and its moons. RADAR measurements revealed Titan’s surface geology, observed lakes and seas of mostly liquid methane in the polar regions, measured the depth of several lakes and seas, detected temporal changes on its surface, and provided key evidence that Titan contains an interior ocean. As a result of the Cassini mission, Titan has gone from an uncharted world to one that exhibits a variety of Earth-like geologic processes and surface-atmosphere interactions. Titan has also joined the ranks of “ocean worlds” along with Enceladus and Europa, which are prime targets for astrobiological research.

Saturn

Using qualitative and re?exive research methodology I explore the cultural role that the planet Saturn plays in contemporary communities of astrologers and the astrological way of life. Through an exploration of Saturn as a mythical ?gure and as symbol, I ?rst discuss astrology’s cultural back­ground and demonstrate that astrologers have a cultural memory that has remained largely loyal to its roots in the Mesopotamian and Hellenistic periods. I then illuminate the way in which for contemporary astrologers sun-sign astrology functions as a contemporary expression of ancient myth. In addition, I examine the importance of the Saturn Return, which has since become an important symbol of transition, a rite of passage, and a modern form of enchantment that not only marks a life transition but also has the potential to effect one.

Reconnection events in Saturn's magnetotail: Dependence of plasmoid occurrence on planetary period oscillation phase

AbstractDuring its exploration of Saturn's magnetotail the Cassini magnetometer has detected many in situ examples of magnetic reconnection, in the form of plasmoids, traveling compression regions (TCRs), and dipolarizations. Meanwhile, many magnetospheric phenomena have been shown to be organized with particular regularity by planetary period oscillation systems driven separately from the Northern and Southern Hemispheres of the planet. Here we examine the relationship between the occurrence of plasmoids and TCRs and the magnetic phases of the northern and southern systems. We find a striking degree of organization of the events by both northern and southern phases, with events linked preferentially to intervals in which the magnetospheric plasma and field lines are displaced outward from the planet and the current sheet thinned, both effects being likely to favor the occurrence of reconnection and plasmoid‐related mass loss. Little evidence is found for significant visibility effects associated with north‐south motions of the plasma sheet.

Magnetic reconnection in Saturn's magnetotail: A comprehensive magnetic field survey.

Reconnection within planetary magnetotails is responsible for locally energizing particles and changing the magnetic topology. Its role in terms of global magnetospheric dynamics can involve changing the mass and flux content of the magnetosphere. We have identified reconnection related events in spacecraft magnetometer data recorded during Cassini's exploration of Saturn's magnetotail. The events are identified from deflections in the north‐south component of the magnetic field, significant above a background level. Data were selected to provide full tail coverage, encompassing the dawn and dusk flanks as well as the deepest midnight orbits. Overall 2094 reconnection related events were identified, with an average rate of 5.0 events per day. The majority of events occur in clusters (within 3 h of other events). We examine changes in this rate in terms of local time and latitude coverage, taking seasonal effects into account. The observed reconnection rate peaks postmidnight with more infrequent but steady loss seen on the dusk flank. We estimate the mass loss from the event catalog and find it to be insufficient to balance the input from the moon Enceladus. Several reasons for this discrepancy are discussed. The reconnection X line location appears to be highly variable, though a statistical separation between events tailward and planetward of the X line is observed at a radial distance of between 20 and 30R S downtail. The small sample size at dawn prevents comprehensive statistical comparison with the dusk flank observations in terms of flux closure.

Saturn in C. G. Jung's Liber Primus

“Saturn in C. G. Jung's Liber Primus: An Astrological Meditation” is an archetypal astrological exploration of Saturn. Focusing on one painting in Liber Primus that contains astrological images of Aquarius, Leo, Saturn, and the Sun, this essay looks at these astrological principles and dynamics as they appear in C. G. Jung's birth chart, in specific ideas and experiences in Liber Primus, and what emerges in his later work with respect to the theme of the problem of opposites.

Enceladus: Cosmic Gymnast, Volatile Miniworld

The exploration of Saturn by the Cassini/Huygens mission has yielded a rich collection of data about the planet and its rings and moons, in particular its small satellite Enceladus and giant satellite Titan. Once believed too small to be active, Enceladus has been found to be one of the most geologically dynamic objects in the solar system. Among the surprises are a watery, gaseous plume; a south polar hot spot; and a surface marked by deep canyons and thick flows.

A Comparative Study of the Outer Planets before the Exploration of Saturn by Cassini/Huygens: Introduction

A Comparative Study of the Outer Planets before the Exploration of Saturn by Cassini/Huygens: Introduction

Transport and acceleration of plasma in the magnetospheres of Earth and Jupiter and expectations for Saturn

The first comparative magnetospheres conference was held in Frascati, Italy thirty years ago this summer, less than half a year after the first spacecraft encounter with Jupiter’s magnetosphere (Formisano, V. (Ed.), The Magnetospheres of the Earth and Jupiter, Proceedings of the Neil Brice Memorial Symposium held in Frascati, Italy, May 28–June 1, 1974. D. Reidel Publishing Co., Boston, USA, 1975). Disputes highlighted various issues still being investigated, such as how plasma transport at Jupiter deviates from the prototypical form of transport at Earth and the role of substorms in Jupiter’s dynamics. Today there is a wealth of data on which to base the analysis, data gathered by seven missions that culminated with Galileo’s 8-year orbital tour. We are still debating how magnetic flux is returned to the inner magnetosphere following its outward transport by iogenic plasma. We are still uncertain about the nature of sporadic dynamical disturbances at Jupiter and their relation to terrestrial substorms. At Saturn, the centrifugal stresses are not effective in distorting the magnetic field, so in some ways the magnetosphere appears Earthlike. Yet the presence of plasma sources in the close-in equatorial magnetosphere parallels conditions at Jupiter. This suggests that we need to study both Jupiter and Earth when thinking about what to anticipate from Cassini’s exploration of Saturn’s magnetosphere. This paper addresses issues relevant to plasma transport and acceleration in all three magnetospheres.

As launch to Saturn nears, plutonium controversy increases

After years of rigorous planning and testing, NASA scientists say they are convinced that the mid‐October launch of the $3.4 billion, plutonium‐powered Cassini mission to Saturn poses nearly no risk to the Earth and will provide an astronomical treasure of information about the sixth rock from the Sun. They say that once the mission reaches the Saturnian neighborhood in the year 2004, it also will offer important insights about the planet's icy rings, and about Titan, Saturn's largest moon, which exhibits atmospheric conditions that may have existed on a primordial Earth.A growing opposition, however, argues that the exploration of Saturn should wait until an alternative electrical generating system is developed. These critics—who include some former NASA employees, scientists, and activists—are concerned that the spacecraft's 72.3 pounds of plutonium 238 poses a potential catastrophic risk to the Earth's population, if the substance is released. Cassini carries the most plutonium ever used on a space mission, and NASA says this is the only means for powering the heavy spacecraft in extremely dim sunlight.

Saturn mission feels Congress' frustration

Saturn mission feels Congress' frustration

Cassini Titan Radar Mapper

The Cassini Titan Radar Mapper is a multimode radar instrument designed to probe the optically inaccessible surface of Titan, Saturn's largest moon. The instrument is to be included in the payload of the Cassini Saturn Mission, scheduled for launch in 1995. The individual modes of Cassini Radar Mapper will allow topographic mapping and surface imaging at few hundred meters resolution. The requirements that lay behind the design are briefly discussed, and the configuration and capability of the instrument are described. The present limited knowledge of Titan's surface and the measurement requirements imposed on the radar instrument are addressed. Also discussed are the Cassini mission and the projected orbits, which imposed another set of design constraints that led to the multitude of modes and to an unconventional antenna configuration. The antenna configuration and the different radar modes are described. >

Statistical study of Saturn electrostatic discharges

During the Voyager Saturn mission the Planetary Radio Astronomy (PRA) experiment observed sporadic broadband emissions (20 KHz to at least 40 MHz) during a few days around the Voyager 1 and 2 closest approaches to the planet. These emissions are interpreted to arise from short‐lived electrostatic discharges in the vicinity of Saturn. We have made a statistical study of their characteristics from the Voyager 1 and 2 high‐band data of the PRA experiment (1.2 MHz to 40.2 MHz). In this paper, we compare the results obtained for the two encounters and describe in detail the appearance, intensity, and spectrum of the Saturn electrostatic discharges (SED). We show that the SED spectrum is likely smooth in the frequency range 1–40 MHz and extends down to 20 KHz. We have determined the period of the SED occurrence, which seems to be slightly different for Voyager 1 and 2 encounters (10 hours 9 min for the Voyager 1 encounter and 10 hours 00 min for the Voyager 2 encounter). An attempt to interpret the statistical results is presented.

Maneuver Sequence Design for the Post-Jupiter Leg of the Pioneer Saturn Mission

Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.

Outer Planet Mission Guidance and Navigation for Spinning Spacecraft

The orbit determination accuracies, maneuver results, and navigation system specification for spinning Pioneer planetary probe missions are analyzed to aid in determining the feasibility of deploying probes into the atmospheres of the outer planets. Radio-only navigation suffices for a direct Saturn mission and the Jupiter flyby of a Jupiter/Uranus mission. Saturn ephemeris errors (1000 km) plus rigid entry constraints at Uranus result in very high velocity requirements (140 m/sec) on the final legs of the Saturn/Uranus and Jupiter/Uranus missions if only Earth-based tracking is employed. The capabilities of a conceptual V-slit sensor are assessed to supplement radio tracking by star/satellite observations. By processing the optical measurements with a batch filter, entry conditions at Uranus can be controlled to acceptable mission-defined levels (+ or - 3 deg) and the Saturn-Uranus leg velocity requirements can be reduced by a factor of 6 (from 139 to 23 m/sec) if nominal specified accuracies of the sensor can be realized.

Earth-Line Maneuver Strategies for the Extended Pioneer 1 Jupiter/Saturn Mission

Pioneer 11 was launched in April 1973, eight months before the Jupiter encounter of the front-running twin spacecraft, Pioneer 10. Near-Earth maneuvers placed Pioneer 11 on an interim flight path designed to retain a later retargeting capability to repeat the Pioneer 10 flyby geometry or encounter a wide variety of alternate Jupiter aimpoints, including one resulting in an extended mission to Saturn. Pioneer 11 was retargeted for the extended mission in April 1974, subsequent to the successful Jupiter encounter of Pioneer 10 in December 1973. Pioneer 11 successfully met its Jupiter objectives during flyby in December 1974 and is now headed for a Saturn encounter in September 1979. This paper presents the retargeting and trimming maneuver strategies and analyses that were required to assure the productive Jupiter encounter and to demonstrate the feasibility of achieving a subsequent Saturn mission.