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

• Lunar South Pole-Aitken Basin Sample Return—The primary science objective of this
mission is to return samples from this ancient and deeply excavated impact basin to Earth for
characterization and study. In addition to returning at least 1 kilogram of samples, this mission would
also document the geologic context of the landing site with high-resolution and multispectral surface
imaging.
• Saturn Probe—This mission is intended to determine the structure of Saturn’s atmosphere as
well as noble gas abundances and isotopic ratios of hydrogen, carbon, nitrogen, and oxygen. The flight
system consists of a carrier-relay spacecraft and a probe to be deployed into Saturn’s atmosphere. The
probe makes continuous in situ measurements of Saturn’s atmosphere as it descends ~250 km from its
initial entry point and relays measurement data to the carrier spacecraft.
• 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. Primary science objectives for this mission include the characterization of the bulk
composition, interior structure, and near-surface volatiles.
• Venus In Situ Explorer—The primary science objectives of this mission are to examine the
physics and chemistry of Venus’ atmosphere and crust. This 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 mission architecture consists of a
lander that acquires atmospheric measurements during descent, and then carries out a brief period of
remote sensing and in situ measurements on the planet’s surface.
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 and Technical
Evaluations performed in support of this decadal survey have shown that it may be possible to execute
them within the New Frontiers cap (Appendix C).
The committee’s list of recommended New Frontiers mission candidates differs somewhat from
the one in the most recent NRC report on New Frontiers. 11 One mission has been added (Saturn Probe),
two have been removed (Asteroid Rover/Sample Return and Ganymede Observer), and one has been
narrowed in focus (Network Science). These changes result from the committee’s application of the
selection criteria listed at the beginning of this chapter, and reflect changes in scientific knowledge and
programmatic realities since the time of that report.
Medium-Class Mission Decision Rules
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
below as New Frontiers Mission 4 and New Frontiers Mission 5.
Because preparation and evaluation of New Frontiers proposals places a substantial burden on the
community and NASA, it is important to restrict each New Frontiers solicitation to a manageable number
of candidate missions. 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.
PREPUBLICATION COPY—SUBJECT TO FURTHER EDITORIAL CORRECTION
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