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Solar and Space Physics: A Science for a Technological Society
330
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
with the current astronomy decadal survey, recommendations related to ground-based implementations
(e.g., ground-based solar observatories) will be directed to the NSF. The prioritized science goal inventory
from the previous section will form the basis for flight mission prioritization. NASA will provide an axiomatic budget runout for the survey decade, and the committee will allocate these resources into “budget
packages.” Recommended budget packages are:
• Small flight investigations appropriate for the Explorer class;
• A mix of small, medium, and large strategic flight investigations appropriate to goals of the SolarTerrestrial Probes program and the Living With a Star program; and
• If budget guidelines permit, flagship flight investigations may also be recommended.
Life-cycle cost classifications defined by NASA currently are as follows: very small/mission of opportunity, less than $250 million; small, $250 million to $500 million; medium, $500 million to $750 million;
large, $750 million to $1,000 million; and flagship, over $1 billion. These cost ranges are inclusive of
launch vehicles costs.
The survey should address the role of missions of different sizes (small, medium, and large), based on
these cost bracket categories. Note that candidates for individual Explorer and lower-cost flight projects,
including sub-orbital programs, should not be prioritized; they will be solicited and selected as principalinvestigator-led missions on the basis of science merit via NASA’s standard Explorer Announcement of
Opportunity (AO) and NASA Research Announcements processes. However, the strategic value of these
smaller mission programs to the overall science agenda should be appraised and described.
The survey should prioritize “science targets” for the mission implementation opportunities, recommending science objectives and requirements for these missions rather than specific mission design/implementation concepts. However, mission conceptual designs should be used within each prioritized science
area to establish feasibility within its notional budget package. This budget feasibility will be demonstrated
by the NRC’s costing subcontractor on the basis of nominal point designs. Concept mission designs should
not be represented in the final, prioritized list; missions to be flown will be solicited and selected by NASA
on the basis of science and implementation merit versus risk via NASA’s standard AO processes.
The prioritized flight program list recommended in the report should be provided in terms of scientific
problems and measurements, with validated feasibility, and their associated “budget packages,” not in
terms of specific missions. Missions prescribed in The Sun to the Earth—and Beyond and other recent NRC
reports that are not yet in formulation or development must be reprioritized. In contrast, the Solar Orbiter,
Solar Probe Plus, and IRIS missions are in formulation and should not be prioritized. The flight investigations priority list should be supported by a summary of the assumptions underlying the relative rankings.
This summary should, to the extent possible, be accompanied by decision rules that could guide NASA
in adjusting the queue in the event of major unanticipated scientific developments or technical, cost, or
other programmatic changes. It is understood that initiation of missions on this list will depend on actual
resource availability and programmatic factors.
For Solar Probe Plus (SPP), cognizant of the fact that the previous decadal survey ranked Solar Probe
as their highest priority for a “large-class” mission, the decadal survey will consider how the scientific
rationale for a solar probe mission is substantially affected by:
a. Scientific developments since the completion of the 2002 decadal survey; and
b. The projected timeline and instrument complement of the particular implementation of the previous
survey’s recommendation, Solar Probe Plus.
Solar and Space Physics: A Science for a Technological Society
330
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
with the current astronomy decadal survey, recommendations related to ground-based implementations
(e.g., ground-based solar observatories) will be directed to the NSF. The prioritized science goal inventory
from the previous section will form the basis for flight mission prioritization. NASA will provide an axiomatic budget runout for the survey decade, and the committee will allocate these resources into “budget
packages.” Recommended budget packages are:
• Small flight investigations appropriate for the Explorer class;
• A mix of small, medium, and large strategic flight investigations appropriate to goals of the SolarTerrestrial Probes program and the Living With a Star program; and
• If budget guidelines permit, flagship flight investigations may also be recommended.
Life-cycle cost classifications defined by NASA currently are as follows: very small/mission of opportunity, less than $250 million; small, $250 million to $500 million; medium, $500 million to $750 million;
large, $750 million to $1,000 million; and flagship, over $1 billion. These cost ranges are inclusive of
launch vehicles costs.
The survey should address the role of missions of different sizes (small, medium, and large), based on
these cost bracket categories. Note that candidates for individual Explorer and lower-cost flight projects,
including sub-orbital programs, should not be prioritized; they will be solicited and selected as principalinvestigator-led missions on the basis of science merit via NASA’s standard Explorer Announcement of
Opportunity (AO) and NASA Research Announcements processes. However, the strategic value of these
smaller mission programs to the overall science agenda should be appraised and described.
The survey should prioritize “science targets” for the mission implementation opportunities, recommending science objectives and requirements for these missions rather than specific mission design/implementation concepts. However, mission conceptual designs should be used within each prioritized science
area to establish feasibility within its notional budget package. This budget feasibility will be demonstrated
by the NRC’s costing subcontractor on the basis of nominal point designs. Concept mission designs should
not be represented in the final, prioritized list; missions to be flown will be solicited and selected by NASA
on the basis of science and implementation merit versus risk via NASA’s standard AO processes.
The prioritized flight program list recommended in the report should be provided in terms of scientific
problems and measurements, with validated feasibility, and their associated “budget packages,” not in
terms of specific missions. Missions prescribed in The Sun to the Earth—and Beyond and other recent NRC
reports that are not yet in formulation or development must be reprioritized. In contrast, the Solar Orbiter,
Solar Probe Plus, and IRIS missions are in formulation and should not be prioritized. The flight investigations priority list should be supported by a summary of the assumptions underlying the relative rankings.
This summary should, to the extent possible, be accompanied by decision rules that could guide NASA
in adjusting the queue in the event of major unanticipated scientific developments or technical, cost, or
other programmatic changes. It is understood that initiation of missions on this list will depend on actual
resource availability and programmatic factors.
For Solar Probe Plus (SPP), cognizant of the fact that the previous decadal survey ranked Solar Probe
as their highest priority for a “large-class” mission, the decadal survey will consider how the scientific
rationale for a solar probe mission is substantially affected by:
a. Scientific developments since the completion of the 2002 decadal survey; and
b. The projected timeline and instrument complement of the particular implementation of the previous
survey’s recommendation, Solar Probe Plus.