CfA-led mission to explore the sun selected by NASA for Next Step

NASA has selected a new heliophysics mission focused on investigating the sun's middle corona—an enigmatic region of the sun's atmosphere driving solar activity—for a "Phase A" mission definition study.

The mission, called the EUV CME and Coronal Connectivity Observatory (ECCCO), is being led by the Smithsonian Astrophysical Observatory (SAO), part of the Center for Astrophysics | Harvard & Smithsonian (CfA).

According to NASA, "the purpose of Phase A is to develop a proposed mission/system architecture that is credible and responsive to program expectations, requirements, and constraints on the project, including resources."

"ECCCO will answer fundamental questions about the origins of the mass and energy flow that link the sun to the outer corona and overall heliosphere, the 'bubble' of space encompassing the solar system 'inflated' by the solar wind," said Smithsonian Astrophysical Observatory astrophysicist Dr. Kathy Reeves, ECCCO principal investigator from the CfA. "We'll have unique data that have the potential to reveal the deep connection between the sun and its larger environment in the heliosphere."

SAO will be responsible for ECCCO's design, development, acquisition, assembly, testing, pre-flight calibration, and delivery of the science payload (one imager and two spectrometers). It will also lead and direct the science planning of the investigation, oversee development of the operations plan, support payload operations, and be responsible for archiving of the flight data. Finally, SAO will manage and administer the contract with NASA and coordinate formal reporting to NASA.

The mission focuses on imaging and spectroscopy of the middle corona in extreme ultraviolet (EUV) wavelengths, tracking events like coronal mass ejections (CMEs) from their origins until they leave the sun. CMEs are huge bursts of charged particles from the corona threaded with intense magnetic fields ejected from the sun over the course of several hours. CMEs reaching Earth can generate geomagnetic storms and cause anomalies in and disruptions to modern conveniences such as electronic grids and GPS systems.

The Southwest Research Institute (SwRI) is a partner with the CfA on ECCCO and will manage the project as well as its science and mission operations centers. Ball Aerospace will build the spacecraft.

"We've explored the sun itself extensively over the last few decades," said Dan Seaton, the deputy principal investigator for ECCCO from SwRI. "Yet the middle corona remains a great mystery, and ECCCO will finally help reveal its secrets."

ECCCO's innovative high-sensitivity instruments, when trained on the middle corona, will return wide-field data that are critical to understanding eruptive events and solar wind streams. The ECCCO-I imager sees the full multi-thermal corona from the surface of the sun out to three solar radii away from the star. The twin ECCCO-S spectrographs are designed to provide unprecedented temperature and density diagnostics from the solar disk to the middle corona.

"We are thrilled that ECCCO is moving to this next important step," said CfA Director Lisa Kewley. "The sun is our nearest star and affects the entire solar system including Earth, and ECCCO will help us learn so much more about its behavior."

The ECCCO mission builds on the CfA's extensive history and expertise of designing and building instruments for many different questions in science, including heliophysics. For example, the CfA has played major roles with such missions as the Parker Solar Probe, the Solar Dynamics Observatory, the Hi-C telescope, the Hinode solar observatory, and many others.

NASA's Explorers Program, to which ECCCO belongs, provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches.

Provided by Harvard-Smithsonian Center for Astrophysics