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Galileo Europa Mission (GEM) Tour Design
The orbital tour trajectory that was selected for the Galileo mission includes ten close flybys of the Galilean satellites Europa, Ganymede, and Callisto, additional distant flybys of these satellites, lo torous observations, and many other events that provide broad opportunities for scientific observations.
Satellite tour design for the Galileo mission
The design of Galileo's tour of Jupiter's Galilean satellites is discussed. The Galileo mission is reviewed, and the gravity-assist trajectory design is described. Attention is given to mission constraints and science requirements, several tour design strategies, and a strawman satellite tour. The software used to design a satellite tour is examined.
Galileo Europa Mission (GEM) Tour Design
Galileo has received approval for a two-year follow-on mission, called the Galileo Europa (GEM). A three-phase tour has been designed for GEM that includes eight Europa encounters, four Callisto flybys, and two Io encounters to end the GEM in Decemger 1999. Although science desires for the satallite encountes were of primary importance to the tour design, the flyby conditions were also necessarily selected on the basis of the gravity assist they contributed to the trajectory. The tour design was heavily influenced by the requirement to return to Io, since the radiation exposure that acompanies such a flyby may serverely degrade the health of the spacecraft.
New Tools for Tour Design: Swiss Cheese Plot, Invariant Funnel, and Resonant Encounter Map
We define a new set of tools for tour design introduced in previous work: the”Swiss Cheese Plot,” ”Invariant Funnel,” and ”Resonant Encounter Map.” These tools promise to be useful in designing, analyzing, and navigating low-energy trajectories through multi-body systems. We review and clarify methods for generating the swiss cheese plot and invariant funnels in the Circular Restricted Three-Body Problem. We introduce the resonant encounter map as a graphical representation of the three-body design space, similar to the pork-chop plot for the two-body problem. We also discuss some interesting characteristics of the resonant encounter map and its connection to the invariant manifolds of periodic libration orbit
Satellite tour design for the Cassini mission
The mission design for the Cassini satellite tour of Saturn is described. The use of Titan encounters for gravity-assisted trajectory shaping to satisfy atmosphere, magnetosphere, and satellite science requirements is discussed. Three candidate satellite tours that illustrate the tradeoffs between different strategies to satisfy the science objectives are presented. Tour characteristics for a 4yr mission include at least 30 Titan encounters to provide a minimum of 90 deg orbit rotation for either a magnetotail petal orbit or noon petal orbit; evenly distributed Titan ground tracks for radar mapping coverage; at least 2 Iapetus and 1 Enceladus close flybys; inclined orbits during the first 3 yr to provide Earth and Sun occultations by Saturn and its rings; and Polar orbits during the fourth year.
Jovian Tour Design for Orbiter and Lander Missions to Europa
This paper presents trajectory options for the lander and for the orbiter missions, while the trajectory design for the flyby option was presented in a previous work.
Post Galileo-Europa-Mission Satellite Tour Design
The Galileo orbiter mission as originally envisioned would orbit Jupiter eleven times, closely encountering either Europa, Ganymede, or Callisto on ten of those orbits. This nominal or prime mission began with Jupiter orbit insertion on December 7, 1995 and ended as designed ten encounters later on December 1, 1997. An extension to this nominal mission was proposed, developed and accepted in 1997 and was designed to continue orbital operations through an additional two years until December 31, 1999. This follow- on mission, labelled the Galileo Europa Mission, visits Europa eight times, Callisto four times, and ends with two visits to Io. It augments the prime mission by offering many attractive additional opportunities for science, especially remote sensing. The opportunities include increased scrutiny of Europa, a world with a possible global ocean hidden beneath the surface ice-cap, and the first high resolution images of Io (the only major satellite not encountered during the nominal tour). In 1998 a new effort was begun to investigate a possible extension to GEM. Remote sensing observations will continue to be important but moreover, valuable unique in situ fields and particles measurements will be a high priority motivation in the design and selection of any post-GEM tour. A significant design feature of a possible post-GEM tour would be the extension of the mission through the December 2000 timeframe. This would permit the possibility of simultaneous fields and particles experiments coordinated with the Cassini spacecraft as it swings by the Jupiter system for the final gravity assist enroute to Saturn.
Tour Design Techniques for the Europa Clipper Mission
Europa is one of the most scientifically interesting targets of the solar system, as it may possess the three necessary ingredients for life: an extensive ocean of liquid water, an energy source from tidal heating, and a suite of biogenic elements. To explore the habitability of Europa, NASA is developing the Europa Clipper mission, currently scheduled to be launched in 2022. Europa resides deep inside the gravity well of Jupiter, in a region of the magnetosphere with many trapped ionized particles that get accelerated to near relativistic speeds; a Europa orbiter mission would require a large amount of ∆V for an orbit insertion maneuver, and would only return limited science data before being critically exposed to radiation. To mitigate these issues, Europa Clipper instead only utilizes Europa flybys, connected by Europa-resonant and non-resonant orbits. Science data is collected during high-radiation passes, and returned to Earth during the rest of the Jovian orbits, at a much lower radiation dose exposure. This paper will present several tour tools techniques developed for the design of the Europa Clipper flyby trajectory. In particular, the paper will describe different ways to perform fast line-of-apsides rotations; a new approach to improve the coverage of Europa’s trailing and leading edges, with the lighting conditions considerations; parametric studies of the expected radiation dose and time-of-flight as function of the Europa resonance; and a quick way to estimate the radiation dose for Jovian tours. Other techniques, that were already presented in previous papers, will be reviewed for completeness. We then implement some of the new approaches in the 18F17 tour.
Jovian Tour Design for Orbiter and Lander Missions to Europa
Europa is one of the most interesting targets for solar system exploration, as its ocean of liquid water could harbor life. Following the recommendation of the Planetary Decadal Survey, NASA commissioned a study for a flyby mission, an orbiter mission, and a lander mission. This paper presents the moon tours for the lander and orbiter concepts. The total delta v and radiation dose would be reduced by exploiting multi-body dynamics and avoiding phasing loops in the Ganymede-to- Europa transfer. Tour 11-O3, 12-L1 and 12-L4 are presented in details and their performaces compared to other tours from previous Europa mission studies.
New Tools For Tour Design: Swiss Cheese Plot, Invariant Funnel, and Resonant Encounter Map
No abstract provided
Automated Design of the Europa Orbiter Tour
In this paper we investigate tours of the Jovian satellites Europa, Ganymede, and Callisto for the Europa Orbiter Mission. The principal goal of the tour design is to lower arrival V for the final Europa encounter while meeting all of the design constraints.
Automated Design of the Europa Orbiter Tour
In this paper we investigate tours of the Jovian satellites Europa, Ganymede, and Callisto for the Europa Orbiter Mission. The principal goal of the tour design is to lower arrival V(sub infinity) for the final Europa encounter while meeting all of the design constraints. Key constraints arise from considering the total time of the tour and the radiation dosage of a tour. These tours may employ 14 or more encounters with the Jovian satellites, hence there is an enormous number of possible sequences of these satellites to investigate. We develop a graphical method that greatly aids the design process.
Automated Design of the Europa Orbiter Tour
In this paper we investigate tours of the Jovian satellites Europa Ganymede, and Callisto for the Europa Orbiter Mission. The principal goal of the tour design is to lower arrival V_ for the final Europa encounter while meeting all of the design constraints. Key constraints arise from considering the total time of the tour and the radiation dosage of a tour. These tours may employ 14 or more encounters with the Jovian satellites. hence there is an enormous number of possible sequences of these satellites to investigate. We develop a graphical method that greatly aids the design process.
Galileo Jupiter encounter and satellite tour trajectory design
The trajectory design process for the Galilean satellite probe, expected to be launched in January 1982, is examined and its interplanetary path, emphasizing arrival dates and the Mars flyby, is presented. The Galileo spacecraft is of dual spin design, combining features of Pioneer, a spinning craft, and Voyager which was 3-axis stabilized. The design of the initial orbit from Orbiter deflection through Jupiter to the beginning of the satellite tour is discussed as well as the use of an Io gravity assist flyby to achieve Jupiter orbit insertion, and the effects of solar perturbation on the initial orbit. Detail is given to the entire satellite tour trajectory design process, starting from the requirements and constraints placed on the tour through the conic design to the final numerically integrated trajectories.
The Galileo orbital tour for the 1986 launch opportunity
The trajectory characteristics of the selected Galileo orbital tour for the May 1986 launch opportunity are presented, and the interplay between tour design and science requirements is discussed. The orbital tour design concepts are summarized, and the research objectives in the areas of magnetospheric science, satellite imaging, observations of the Jupiter atmosphere, and radio science are discussed. Each of the encounter with the moons of Jupiter that would have occurred if the launch opportunity had been utilized are described, giving the dates of the planned encounters. Trajectory pole views and earth views of occultations during encounters are diagrammed.