Vision and Voyages for Planetary Science in the - Solar System ...

These five were selected from the seven listed above based on the criteria described at the
beginning of this chapter: science return per dollar, programmatic balance, technological readiness, and
availability of spacecraft trajectories. All offer the potential for exceptional science return per dollar.
Together they address a set of high-priority science objectives that is well balanced across the solar
system, especially when considered in conjunction with the large missions recommended below. And all
are technically mature and have available trajectories. No relative priorities are assigned to these five
mission candidates; instead, the selection among them should be made on the basis of competitive peer
review.
If either SAGE or MoonRise is selected by NASA in 2011 as the third New Frontiers
mission, the corresponding mission candidate should be removed from the above list of five,
reducing the number of candidates from which NASA should make the New Frontiers Mission 4
selection to four.
For the New Frontiers Mission 5 selection, the Io Observer and the Lunar Geophysical
Network should be added to the list of remaining candidate missions, increasing the total number of
candidates for that selection to either five or six. Again, no relative priorities are assigned to any of these
mission candidates.
High-Priority Large-Class Missions
Large Class Missions
The decadal survey has identified five candidate Flagship missions for the decade 2013-2022.
All of these missions have been judged to have exceptional science merit when considered in light of the
community-derived science priorities described in Chapter 3. All are correspondingly costly. In
alphabetical order, they are:
• Enceladus Orbiter—This mission would investigate that saturnian satellite’s cryovolcanic
activity, habitability, internal structure, chemistry, geology, and interaction with the other bodies of the
Saturn system. In particular, it would provide extensive characterization of Enceladus’ plumes, first
discovered during the Cassini mission. Upon arrival at Saturn, the spacecraft would orbit the planet for
~3.5 years, allowing numerous flybys of several saturnian moons. It would then go into orbit around
Enceladus, for a baseline 12-month mission there.
• Jupiter Europa Orbiter—This mission is the stand-alone U.S. component of the proposed
NASA-ESA Europa Jupiter System Mission (EJSM). The latter consists of two independently launched
and operated orbiters: the NASA-led Jupiter Europa Orbiter (JEO) and the ESA-led Jupiter Ganymede
Orbiter. Specific science objectives for the JEO include characterization of Europa’s ocean and interior,
ice shell, chemistry and composition, and the geology of prospective landing sites. The preliminary
mission timeline includes a 30-month jovian system tour phase, followed by a 9-month Europa orbital
phase. The mission also makes observations of Jupiter itself.
• Mars Astrobiology Explorer-Cacher—This mission, MAX-C, is the first of three components
of a joint NASA-ESA Mars Sample-Return campaign. The MAX-C rover is responsible for
characterizing a landing site that has been selected for high science potential, and for collecting,
documenting, and packaging samples for return to Earth. The rover is also capable of conducting highpriority
in situ science on the martian surface. MAX-C is envisioned to be carried out jointly with ESA’s
ExoMars rover mission, with a single entry, descent and landing system delivering both rovers to the
same landing site. In evaluating the science return per dollar of MAX-C, the committee considered the
science return of the full Mars Sample Return campaign, and the costs of the full NASA portion of that
campaign.
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