Abstract
Based on the overwhelming success of the Cassini/Huygens 4-year tour of Saturn from July 2004 to June 2008, NASA Headquarters approved at least two years of extended mission for continued study of the target-rich Saturnian system. After a rigorous phase of science objective definition and trajectory design and analysis, the Cassini project initiated an efficient, scientifically intense and operationally challenging mission phase, including 60 orbits around Saturn, 26 close Titan flybys, and 10 close icy satellite flybys — including seven more flybys of Enceladus. At the conclusion of the 2-year extended mission, substantial operating margins should be present with some fascinating options for further extensions
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Notes
- 1.
Rs = 60;330 km (Saturn equatorial radius at 100 mbar)
- 2.
Special cases do exist where only one deterministic maneuver is utilized between targeted encounters.
- 3.
With large maneuvers or large third-body perturbations, leveraging transfers or other tricks are possible.
- 4.
Ansa: The outermost point of a ring that is visible from a particular point in space.
- 5.
Parameter used to describe the set of magnetic field lines that cross a planet's magnetic equator at a number of planet-radii. Each L-shell intersects/connects to specific latitudes on a planet, and hence, are often used to locate/describe phenomenon.
- 6.
Moment when the Sun crosses Saturn's ring plane.
- 7.
Occultation in which the spacecraft passes behind one side of the farthest part of the rings from Saturn, referred to as the ansa, to the other ansa as seen from Earth.
- 8.
For a given icy satellite flyby, a Δv -optimal set of flyby parameters exists. The “freedom” to vary the flyby parameters to increase scientific return is associated with a Δv cost.
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Acknowledgments
The Equinox Mission owes its successful design to the heroic and sustained efforts over 2 years of the Cassini tour designers — Brent Buffington, John Smith and Nathan Strange — and to the dedication of the Cassini science community.
This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Reference to any specific commercial product, process, or service by trade name, trademark, manufacturer or otherwise, does not constitute or imply its endorsement by the United States Government or the Jet Propulsion Laboratory, California Institute of Technology.
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Seal, D.A., Buffington, B.B. (2009). The Cassini Extended Mission. In: Dougherty, M.K., Esposito, L.W., Krimigis, S.M. (eds) Saturn from Cassini-Huygens. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-9217-6_22
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