National Aeronautics and Space Administration Heliophysics Living With a Star Program Enabling Science, Technology, and Exploration to Advance Society 10-Year Vision Beyond 2015 www.nasa.gov Our solar system is governed by the sun, a main-sequence star The LWS program objectives are based upon these goals and are midway through its stellar life. The sun’s influence is wielded as follows: through gravity, radiation, the solar wind, and magnetic fields as 1. Understand solar variability and its effects on the space and they interact with the masses, fields, and atmospheres of planetary Earth environments with an ultimate goal of a reliable predic- bodies. Through the eyes of multiple spacecraft, we see our solar tive capability of solar variability and response. system as a “heliosphere,” a single, interconnected system moving 2. Obtain scientific knowledge relevant to mitigation or accom- through interstellar space. On Earth, this interaction with our star modation of undesirable effects of solar variability on humans is experienced through space weather’s effects on radio and radar and human technology on the ground and in space. transmissions, electrical power grids, and spacecraft electronics, 3. Understand how solar variability affects hardware performance through modifications to the ozone layer, and through climate and operations in space. change. The LWS program emphasizes the science necessary to These objectives flow down from objective 1.4, “understand the understand those aspects of the sun and Earth’s space environ- sun and its interactions with Earth and the solar system, including ment that affect life and society. The ultimate goal of LWS program space weather,” in the 2014 NASA Strategic Plan, the 2014 Science is to provide a scientific understanding of the system, almost to the Plan for NASA’s Science Mission Directorate, and the Heliophysics point of predictability, of the space weather conditions at Earth, Roadmap (Our Dynamic Space Environment: Heliophysics Science interplanetary medium as well as the sun-climate connection. and Technology Roadmap for 2014-2033). Heliophysics Living With a Star Enabling Science, Technology, and Exploration to Advance Society 10-Year Vision Beyond 2015 TABLE OF CONTENTS Executive Summary ......................................1 Chapter 1 • Recommendations from the Decadal Survey ........5 Chapter 2 • Solar Variability and Space Weather ...............7 Chapter 3 • Assessment of the Existing Program..............13 Chapter 4 • LWS Program Elements ........................25 Chapter 5 • Future Opportunities and Challenges .............35 Chapter 6 • Global Cooperation in LWS Science ..............49 Chapter 7 • Deliverables to Address Societal Needs and User Communities ........................51 LWS and the New Heliosphere by Lika Guhathkurta This report articulates a vision for NASA’s Living With a Star health is the topic of ongoing studies. Deep-space astronauts (LWS) program spanning the decade 2015 through 2025. The have even more to worry about. Outside the protective cocoon vision is bold, and it must be, because the next decade could of Earth’s atmosphere and magnetic field, they will absorb an be unlike anything we’ve experienced in the Space Age. enhanced dose of primary cosmic rays with uncertain conse- quences for health. One study has shown that during the Apollo Only a few years ago, the sun emerged from the deepest Solar Era astronauts could travel nearly 900 days in deep space Minimum in a hundred years. During the extreme quiet of 2007- before reaching NASA safety limits; in the decade ahead, the 2009, the solar wind became slow and weak; CMEs lost their “safe time” could be reduced to less than 300 days. punch; and cosmic rays hit a record high for the Space Age. We found ourselves living in a “New Heliosphere.” Our ten year plan for LWS addresses these questions and many others. As the sun thrusts us into territories of research so new Normalcy was not restored by the 11-year swing of the solar that some of them don’t even have names, we will have to bring cycle. Instead of a vigorous Solar Maximum, the 2010s brought together researchers from many disciplines to understand what us a “mini Solar Max,” as peculiar in some ways as the extreme is going on. Interdisciplinary research has been a strong suit Solar Minimum that preceded it. There have been fewer intense of LWS since its inception. In fact, it is a cornerstone of our flares, fewer strong geomagnetic storms, and fewer SEPs than future plans. any other Solar Max in modern times. We have identified seven “Strategic Science Areas” of special Given these events, there is no reason to think that the decade relevance to the New Heliosphere. ahead will be “normal.” Indeed, there is some evidence that the sun might plunge into a Minimum even deeper than the one in • SSA-0, Physics-based Understanding to Enable Forecast- 2007-2009. If the sun’s magnetic field weakens and the solar ing of Solar Electromagnetic, Energetic Particle, and Plasma wind flags, researchers anticipate a significant surge of cosmic Outputs Driving the Solar System Environment and inputs to rays penetrating the solar system, eclipsing old records. Earth’s atmosphere • SSA-1, Physics-based Geomagnetic Forecasting Capability The questions this raises are very difficult to answer. For in- • SSA-2, Physics-based Satellite Drag Forecasting Capability stance: • SSA-3, Physics-based Solar Energetic Particle Forecasting Capability What effect will these cosmic rays have on the chemistry of • SSA-4, Physics-based TEC Forecasting Capability Earth’s upper atmosphere? Past experience may be of little • SSA-5, Physics-based Scintillation Forecasting Capability help. During an extreme Solar Minimum, the upper atmosphere • SSA-6, Physics-based Radiation Environment Forecasting could collapse into a new state, prompted by a sharp drop Capability in solar UV radiation. Its response to cosmic rays could be anyone’s guess. Using a variety of tools developed during the first 10 years of LWS (such as LWS Working Groups and TR&Ts), we will attack How will the new radiation environment alter Earth’s ionosphere, these interdisciplinary problems with the understanding that where density gradients and scintillation can distort GPS signals what we used to know may not apply in the years ahead. In and critical HF emergency communications? Forecasters have all cases, our focus will be on developing fundamental science lots of experience with Solar Max, which puffs up the iono- to serve the end user. What exactly do power grid operators sphere and increases its ionization. But what about extreme want to know to help them prevent blackouts? That question Solar Minimum? The ionosphere of 2015-2025 could become will guide our work in SSA-1. Which forecasting tools do satel- very unfamiliar. lite operators need to safeguard their fleets against changes in atmospheric drag? That question will guide our work in SSA-2. What can air travelers and astronauts expect? Even during Each of the strategic science areas focuses on delivering the “normal” times, cosmic rays penetrate Earth’s atmosphere, key science needed by society to protect our technologies and creating a secondary spray of radiation that is absorbed by our increasingly space-based infrastructures. airplane passengers. The dose is probably not enough to harm occasional fliers. Pilots, on the other hand, are classified by the The heliosphere we study in the next ten years may not be International Commission on Radiological Protection (ICRP) much like the one we are used to. We must learn to adapt. as “occupational radiation workers,” and the impact on their LWS is ready. Living With a Star Program Steering Committee Members: Nathan Schwadron • UNH (Chair) Tony Mannucci • JPL (Co-Chair) Spiro Antiochus • GSFC Amitava Bhattacharjee • Princeton Tamas Gombosi • U Michigan Nat Gopalswamy • NASA/GSFC Farzad Kamalabadi • U Illinois Jon Linker • PSI Peter Pilewiske • U Colorado Antti Pulkkinen • NASA/GSFC Mario Bisi • Rutherford Appleton Laboratory Harlan Spence • UNH Kent Tobiska • U Utah/SET Daniel Weimer • Virginia Tech Paul Withers • BU Liaisons to the LWS TR&T/Science Steering Committee: Masha Kuznetsova • GSFC Slava Lukin • NSF Kent Miller • AFOSR Therese Moretto Jorgensen • NSF Terry Onsager • NOAA Ilia Roussev • NSF Rodney Viereck • NOAA LWS Program Ex Officio: Madhulika Guhathakurta • NASA/HQ Bob Leamon • NASA/HQ Jenny Rumburg • NASA/HQ Executive Summary NASA’s Living With a Star program addresses societal needs LWS faces fundamental challenges in the coming decade for scientific understanding to enable prediction of the causes that will require innovative approaches to obtaining necessary and effects of space weather events. Our society’s heavy observations and developing needed research in the LWS reliance on technologies affected by the space environment, program. LWS is facing the growing complexity of the field such as GPS; the enormous population of airline customers; and the societal demands for improved services. The highest the interest in space tourism; and the developing plans for long priority recommendation for new funding by the Heliophysics duration human exploration missions are clear examples that Decadal Survey is implementation of DRIVE (Diversify, Realize, demonstrate urgent needs for predictive space weather models Integrate, Venture, Educate) that represents an integrated ap- and detailed understanding of space weather effects and risks. proach to the management of crucial infrastructure