Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
RECOMMENDATIONS
97
• The missions must be executed through a funding line with a fixed budget profile.
• The missions must be cost-capped, with a specified ceiling on full life-cycle costs.
• The missions must be PI-led, with the PI fully empowered and motivated to make scientific and
mission trade-offs necessary to remain within the cost cap.
• The NASA center and/or other organization with management capabilities to which project management responsibility is assigned will be selected competitively. The goal is to assist the PI in the successful
execution of the mission for minimum cost.
• Management of the STP program will be assigned by NASA Headquarters to a NASA center using
a competitive process. The center must demonstrate ability to successfully execute the program for the
minimum cost. Program management must also be reviewed periodically by Headquarters and be subject
to reassignment in the event of unsatisfactory performance.
• Missions must be confirmed with reserves adequate for remaining within the cost cap and should
have descope options in case the cost cap is breached. If there is cost growth beyond the control of the
PI, the impacts have to be absorbed within the funding line, with no additional liens on other program
elements in the Heliophysics Division.
• The missions will be selected competitively. However, each selection will be restricted to a specific
science goal in order to achieve the prioritized strategic objectives described in this survey.
The survey committee recommends that NASA’s Solar-Terrestrial Probes program be restructured as a
moderate-scale, competed, principal-investigator-led (PI-led) mission line that is cost-capped at $520
million per mission in fiscal year 2012 dollars including full life-cycle costs.
Recommended STP Science Targets [R3.1, R3.2, and R3.3]
Although the new STP program would involve moderate missions being chosen competitively, the
survey committee recommends that their science targets be ordered as follows so as to systematically
advance understanding of the full coupled solar-terrestrial system.
1. The first new STP science target is to understand the outer heliosphere and its interaction with
the interstellar medium, as illustrated by the reference mission 11 Interstellar Mapping and Acceleration
Probe (IMAP). Implementing IMAP as the first of the STP investigations will ensure coordination with
NASA Voyager missions. The mission implementation also requires measurements of the critical solar
wind inputs to the terrestrial system.
2. The second STP science target is to provide a comprehensive understanding of the variability in
space weather driven by lower-atmosphere weather on Earth. This target is illustrated by the reference
mission Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC).
3. The third STP science target is to determine how the magnetosphere-ionosphere-thermosphere
system is coupled and how it responds to solar and magnetospheric forcing. This target is illustrated
by the reference mission Magnetosphere Energetics, Dynamics, and Ionospheric Coupling Investigation
(MEDICI).
11 In this report, the committee uses the terms “reference mission” and “science target” interchangeably, given that the mission
concepts were developed specifically to assess the cost of addressing particular high-priority science investigations. The concepts
presented in this report underwent an independent cost and technical analysis by the Aerospace Corporation, and they have been
given names for convenience; however, the actual recommendation from the committee is to address the science priorities enumerated in the reference mission concept.
Solar and Space Physics: A Science for a Technological Society
RECOMMENDATIONS
97
• The missions must be executed through a funding line with a fixed budget profile.
• The missions must be cost-capped, with a specified ceiling on full life-cycle costs.
• The missions must be PI-led, with the PI fully empowered and motivated to make scientific and
mission trade-offs necessary to remain within the cost cap.
• The NASA center and/or other organization with management capabilities to which project management responsibility is assigned will be selected competitively. The goal is to assist the PI in the successful
execution of the mission for minimum cost.
• Management of the STP program will be assigned by NASA Headquarters to a NASA center using
a competitive process. The center must demonstrate ability to successfully execute the program for the
minimum cost. Program management must also be reviewed periodically by Headquarters and be subject
to reassignment in the event of unsatisfactory performance.
• Missions must be confirmed with reserves adequate for remaining within the cost cap and should
have descope options in case the cost cap is breached. If there is cost growth beyond the control of the
PI, the impacts have to be absorbed within the funding line, with no additional liens on other program
elements in the Heliophysics Division.
• The missions will be selected competitively. However, each selection will be restricted to a specific
science goal in order to achieve the prioritized strategic objectives described in this survey.
The survey committee recommends that NASA’s Solar-Terrestrial Probes program be restructured as a
moderate-scale, competed, principal-investigator-led (PI-led) mission line that is cost-capped at $520
million per mission in fiscal year 2012 dollars including full life-cycle costs.
Recommended STP Science Targets [R3.1, R3.2, and R3.3]
Although the new STP program would involve moderate missions being chosen competitively, the
survey committee recommends that their science targets be ordered as follows so as to systematically
advance understanding of the full coupled solar-terrestrial system.
1. The first new STP science target is to understand the outer heliosphere and its interaction with
the interstellar medium, as illustrated by the reference mission 11 Interstellar Mapping and Acceleration
Probe (IMAP). Implementing IMAP as the first of the STP investigations will ensure coordination with
NASA Voyager missions. The mission implementation also requires measurements of the critical solar
wind inputs to the terrestrial system.
2. The second STP science target is to provide a comprehensive understanding of the variability in
space weather driven by lower-atmosphere weather on Earth. This target is illustrated by the reference
mission Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC).
3. The third STP science target is to determine how the magnetosphere-ionosphere-thermosphere
system is coupled and how it responds to solar and magnetospheric forcing. This target is illustrated
by the reference mission Magnetosphere Energetics, Dynamics, and Ionospheric Coupling Investigation
(MEDICI).
11 In this report, the committee uses the terms “reference mission” and “science target” interchangeably, given that the mission
concepts were developed specifically to assess the cost of addressing particular high-priority science investigations. The concepts
presented in this report underwent an independent cost and technical analysis by the Aerospace Corporation, and they have been
given names for convenience; however, the actual recommendation from the committee is to address the science priorities enumerated in the reference mission concept.