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

The Requirement for Power
Of all the multi-mission technologies that support future missions, none is more critical than
high-efficiency power systems for use throughout the solar system. In particular, the committee notes the
special significance of the new highly efficient ASRG, which enables up to 75 percent reduction in use of
plutonium-238 compared to systems based on thermoelectric conversion. As discussed in Chapter 9,
plutonium-238 is a limited and expensive resource for which production is currently at a standstill, and
future production plans are uncertain. Since more efficient use of the limited plutonium supply will help
to ensure a robust and ongoing planetary program, the committee’s highest priority for near-term
multi-mission technology investment is for the completion and validation of the Advanced Stirling
Radioisotope Generator
Progress in these core technology areas will benefit virtually all planetary missions, regardless of
their specific mission profile or destination. The robust Discovery and New Frontiers programs
envisioned by this report would be substantially enhanced by such a commitment to multi-mission
technologies. For the coming decade, it is imperative that NASA expand its investment program in
these fundamental technology areas with the twin goals of both reducing the cost of planetary
missions and improving their scientific capability and reliability. Furthermore, while the
requirements will vary from mission to mission, the scope of these challenges requires careful planning so
that research and development can establish the proper technological foundation. To accomplish this
goal, the committee recommends that NASA expand its program of regular future mission studies
to identify as early as possible the technology drivers and common needs for likely future missions.
Capability-Driven Technology Investments
In structuring its multi-mission technology investment programs it is important that NASA
preserve its focus on fundamental system capabilities rather than solely on individual technology tasks.
An example of such an integrated approach, which NASA is already pursuing, is the advancement of
solar electric propulsion systems to enable a wide variety of new missions throughout the solar system.
This integrated approach consists of linked investments in new thrusters, specifically the NEXT xenon
thruster (Figure 11.2), plus new power processing, propellant feed system technology, and the systems
engineering expertise that enables these elements to work together.
The committee recommends that NASA consider making equivalent systems investments in
the advanced Ultraflex solar array technology that will provide higher power at greater efficiency,
and aerocapture to enable efficient orbit insertion around bodies with atmospheres.
Investing in these system capabilities will yield a quantum leap in our ability to explore the
planets and especially the outer solar system and small bodies. Perhaps more importantly, the availability
of these systems is imperative in order for NASA to meet its solar system exploration objectives within
reasonable budgetary constraints.
PREPUBLICATION COPY—SUBJECT TO FURTHER EDITORIAL CORRECTION
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