NASA's Mission to 'Touch the Sun': Scientists to Make Live Announcement

NASA is set to make a big announcement about its mission to "touch the sun"—its first attempt at flying directly into the sun's atmosphere, where the spacecraft will face unprecedented radiation levels and temperatures of up to 1,400 degrees Celsius.

Scientists working on the mission are set to hold a live event to provide further details about the plans for Solar Probe Plus on Wednesday 31 May at the University of Chicago.

A live stream of the announcement will be shown on NASA TV from 11am EDT (4pm BST). You can watch the broadcast here.

Solar Probe Plus is due to launch in July or August 2018, over 50 years since the concept was first proposed. It will make its close approach to the sun in December 2024, having carried out a flyby of Venus and a host of observations before it enters the solar atmosphere.

"Placed in orbit within four million miles of the sun's surface, and facing heat and radiation unlike any spacecraft in history, the spacecraft will explore the sun's outer atmosphere and make critical observations that will answer decades-old questions about the physics of how stars work," NASA said in a statement. "The resulting data will improve forecasts of major space weather events that impact life on Earth, as well as satellites and astronauts in space."

The panel of speakers at the announcement includes:

• Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington
• Nicola Fox, mission project scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland
• Eugene Parker, S. Chandrasekhar Distinguished Service Professor Emeritus at the University of Chicago
• Eric Isaacs, executive vice president for research, innovation and national laboratories at the University of Chicago
• Rocky Kolb, dean of the Division of the Physical Sciences at the University of Chicago

Solar Probe Plus is scheduled to end in June 2025. After passing Venus, it will approach the sun on a series of elliptical orbits across the inner solar system. The distances of these orbits will gradually decrease, eventually leaving the spacecraft within four million miles of the surface of the sun.

Over its seven-year mission, the spacecraft will have 24 close encounters with the sun. Observations will begin just three months after launch and will continue over the course of the mission.

At its closest approach, the spacecraft will be traveling at 450,000 miles per hour: "That's fast enough to get from Philadelphia to Washington, D.C., in one second," NASA said. In order to withstand the extreme radiation and heat, the probe has been designed with a 4.5-inch-thick (11.43 cm) carbon-composite shield. At its closest point to the sun, the spacecraft will have to survive solar intensity almost 500 times what it would experience orbiting Earth.

One of the scientific goals is to better understand space weather events caused by the sun, and how they impact life on Earth. "One recent study by the National Academy of Sciences estimated that without advance warning a huge solar event could cause two trillion dollars in damage in the US alone, and the eastern seaboard of the US could be without power for a year," NASA said.

"In order to unlock the mysteries of the corona, but also to protect a society that is increasingly dependent on technology from the threats of space weather, we will send Solar Probe Plus to touch the sun."

Jonathan Lunine, director of the Center for Astrophysics and Planetary Science at Cornell University, has served on several NASA advisory and planning committees. Commenting on the mission, he said: "Solar Probe Plus will pass within four million miles of the sun—that's almost eight times closer to the sun than the orbit of Mercury—and provide incredible detail on the dynamic solar atmosphere.

"Solar Probe Plus will fly closer to the sun than the distance at which even close-in exoplanets orbit their own suns, giving us unprecedented information on the kinds of environments these planets experience."