The Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission has been selected by NASA from five mission proposals. It will use pioneering scientific and technological concepts to find out how the solar corona – the outer atmosphere of the Sun – evolves into the heliosphere, the huge 'bubble' created by the solar wind that extends well beyond Pluto's orbit.
By understanding this process, scientists also hope to improve the science behind space weather prediction. Space weather events can disrupt electricity grids, telecommunications and satellite systems, and according to the European Space Agency, a major event could cost Europe more than €15 billion in damaged telecommunications and power infrastructure.
UK scientists are playing a significant role in the development and implementation of the four-satellite mission. STFC RAL Space will provide the detector systems for four visible-light cameras, one hosted on each of the four suitcase-sized spacecraft, as well as performing calibration on the imagery once the mission has been launched.
Dr Jackie Davies from STFC RAL Space is the UK Science Lead for PUNCH, and said: “PUNCH is an exciting, and novel, development in visible-light imaging of the corona and heliosphere. The four cameras will work together to seamlessly track plasma structures across the previously unexplored boundary between the corona and heliosphere. PUNCH will revolutionise the way we track solar wind disturbances from the Sun to Earth. Here at STFC RAL Space we're looking forward to bringing more than four decades of experience leading instruments for solar and heliospheric missions to this new international project."
The mission will provide scientists with highly accurate, three dimensional images which they will use to study the formation of the solar wind, and the causes and predictability of space weather events. This could contribute significantly to future national and international space weather mitigation strategies. The improvement for forecasters to predict space weather could be comparable to the development of weather satellites for hurricane tracking compared to prediction using ground-based weather stations alone.
“PUNCH will, for the first time, reveal the solar wind and corona as parts of a single unified system," said Craig DeForest, the PUNCH Principal Investigator and a Program Director at the Southwest Research Institute (SwRI) in the USA. “RAL Space brings tremendous expertise to this effort. They built the first deep-space heliospheric imagers, on the STEREO mission. The joint collaboration between SwRI, the U.S. Naval Research Laboratory (NRL), and STFC RAL Space builds on the strengths of each institute, and we are thrilled to help maintain international ties with our UK colleagues."
The PUNCH consortium, led by the Southwest Research Institute (SwRI) in San Antonio, Texas, comprises experts from science establishments worldwide, including the Universities of Aberystwyth and St Andrews, as well as STFC RAL Space, in the UK.
PUNCH will launch in 2022 and will orbit the Earth at just 550 km. It will provide an entirely new view of the solar system that will complement the close-up observations made by NASA's Parker Solar Probe mission, launched in 2018, and the UK-led ESA/NASA Solar Orbiter mission due for launch next year.
Image: PUNCH proposes a constellation of four satellites that will study how the Sun’s corona connects with the interplanetary medium, to better understand how coronal structures fuel the solar wind with mass and energy. Credit: Image Courtesy of Southwest Research Institute