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

• Trojan Tour and Rendezvous—This mission is designed to examine two or more small bodies
sharing the orbit of Jupiter, including one or more flybys followed by an extended rendezvous with a
Trojan object..
• Venus In Situ Explorer—The primary science objectives of this mission are to examine the
physics and chemistry of Venus’s atmosphere and crust. The mission attempts to characterize variables
that cannot be measured from orbit, including the detailed composition of the lower atmosphere, and the
elemental and mineralogical composition of surface materials.
The current competition to select the third New Frontiers mission includes the SAGE mission to
Venus and the MoonRise mission to the Moon. These missions are responsive to the science objectives
of the Venus In Situ Explorer and the Lunar South Pole-Aitken Basin Sample Return, respectively. We
assume that the ongoing NASA evaluation of these two missions has validated their ability to be
performed at a cost appropriate for New Frontiers. For the other five listed above, the cost appraisal and
technical evaluations performed in support of this decadal survey show that it may be possible to execute
them within the New Frontiers cap.
In order to achieve an appropriate balance among small, medium, and large missions,
NASA should select two New Frontiers missions in the decade 2013-2022. These are referred to here
as New Frontiers Mission 4 and New Frontiers Mission 5.
New Frontiers Mission 4 should be selected from among the following five candidates:
• Comet Surface Sample Return,
• Lunar South Pole-Aitken Basin Sample Return,
• Saturn Probe,
• Trojan Tour and Rendezvous, and
• Venus In Situ Explorer.
These five missions were selected from the seven listed above based on the criteria of science
return per dollar, programmatic balance, technological readiness, and availability of spacecraft
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.
Large Missions
The decadal survey has identified five candidate Flagship missions for the decade 2013-2022. In
alphabetical order, they are:
• Enceladus Orbiter—This mission will investigate that saturnian satellite’s cryovolcanic
activity, habitability, internal structure, chemistry, geology, and interaction with the other bodies of the
Saturn system.
• Jupiter Europa Orbiter (JEO) —This mission will characterization of Europa’s ocean and
interior, ice shell, chemistry and composition, and the geology of prospective landing sites.
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