MMS and Radiation Belt Storm Probes (RBSP) missions and funding limitations in the Solar-Terrestrial Probes (STP) program, have forced the deferment of the other missions that the decadal survey anticipated would be under development by 2009. Subsequent NASA decisions, also described in Chapter 1, including the reallocation of funding to the Solar Probe Plus mission and the inadequate implementation of the Geospace Network mission, threaten to upset the recommended mission queue and further adversely affect the decadal survey’s Integrated Research Strategy.
The committee makes five recommendations to buttress the survey’s Integrated Research Strategy, to restore as many of the planned concurrent observations as possible, and to mitigate the underlying budget issues.
Recommendation 1: (a) If no budget augmentation is forthcoming that is large enough to support the planned Solar Probe launch date of 2017 without impacting other Heliophysics Division missions, NASA should consult with the community through a formal review mechanism (such as committees of the NASA Advisory Council or other independent, external, community priority-setting bodies) to determine Solar Probe’s priority relative to that of other decadal survey recommendations and its launch date. (b) An implementation plan for the science objectives of the Geospace Network that includes both ionosphere-thermosphere and magnetosphere components should be developed as soon as possible in advance of lower-ranked moderate missions in the 2003 decadal survey’s recommended mission queue.
The queue of missions and their timing as recommended in the decadal survey provide the concurrent observations that underpin the survey’s Integrated Research Strategy and NASA’s Heliophysics Great Observatory.
The decadal survey recommended that NASA should pursue Solar Probe concurrently with its moderate mission recommendations only if the heliophysics budget was augmented to support Solar Probe development. The decadal survey recommended that if that was not possible, NASA should pursue Solar Probe only after the survey’s moderate-mission recommendations had been developed.
NASA recently completed a promising study to redesign the Solar Probe mission, and NASA’s FY 2009 budget reallocates $238 million in the outyears to begin development of the new Solar Probe Plus mission. However, the current FY 2009 budget runout is not large enough to allow Solar Probe Plus to meet its originally planned launch date. Moreover, contrary to the decadal survey, Solar Probe Plus would begin development before most of the survey’s recommended moderate missions, including the Multispacecraft Heliospheric, Geospace Electrodynamic Connections, Magnetospheric Constellation, Solar Wind Sentinels, and Stereo Magnetospheric Imager missions.
Consistent with the mission queue recommended in the decadal survey, NASA should not begin development of the Solar Probe Plus mission unless the Heliophysics Division’s budget is adequate to support the original launch date or unless NASA formally consults with the community and receives a recommendation to begin development of the Solar Probe Plus mission before the remaining moderate missions recommended in the 2003 decadal survey.
The Geospace Network mission was the second-ranked moderate mission recommended in the decadal survey’s Integrated Research Strategy and would consist of two radiation-belt mapping spacecraft and two ionosphere-mapping spacecraft to determine the global response of geospace to solar storms.
As described in Chapter 2, NASA has begun implementing the radiation-belt mapping component of the Geospace Network mission but not its ionosphere mapping component. Because solar storms are transient events, both components of the Geospace Network must operate simultaneously to obtain data that allow understanding of how energy is exchanged between Earth’s radiation belts and its ionosphere during solar storms. Without full implementation of the Geospace Network mission, a state-of-the-art ionosphere-thermosphere mission is the most critical gap in the decadal survey’s Integrated Research Strategy. Thus, NASA should immediately identify and pursue means to reestablish an ionosphere-thermosphere mission to achieve the science goals of the Geospace Network mission.
Consistent with the mission queue recommended in the decadal survey, NASA should begin implementation of the full Geospace Network before pursuing the survey’s other moderate-mission recommendations.
Recommendation 2: Funding for the Heliophysics Explorer Program should be restored to recommended levels as rapidly as possible. The ramp-up in the current 5-year-projection budget is encouraging and should be accelerated as soon as possible.