NASA to unveil probe mission to 'touch the sun'
Published Tuesday, May 30, 2017 12:13PM EDT
Last Updated Tuesday, May 30, 2017 1:24PM EDT
Next summer is going to be a hot one for NASA.
The agency is poised to unveil details of a mission to the heart of the solar system, which will send a spacecraft into the incredible heat of the sun's atmosphere for the first time ever.
The Solar Probe Plus mission is slated to launch in late July or August of next year, with the ultimate goal of passing within 5.9 million kilometres of the surface of the sun. That will take the spacecraft inside the sun's corona, where swirling energy and blasts of heat generate solar winds that affect conditions on Earth.
NASA is expected to provide a rundown of the mission during a livestreamed event in Chicago on Wednesday, at 11 a.m. ET. The mission will be conducted in collaboration with the European Space Agency.
"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," NASA says on the mission's website.
Studying the origins of solar wind is expected to improve scientists' understanding of how space weather impacts satellites, astronauts and the Earth's magnetic field.
"It might sound strange, but the sun is still a very unknown quantity," Paul Delaney, a professor of physics and astronomy at York University, told CTV News Channel on Tuesday.
Delaney says humans need to learn more about the sun's coronal mass ejections, which occasionally blast plasma and magnetically-charged particles into space.
"Humanity really needs to understand what's going on," he said. "If we were in the sights, for example, of a coronal ejection, it potentially could take out every single satellite in orbit around Earth, and that would be bad news for modern society."
The probe will be much closer to the sun than Helios 2, which passed within 43.5 million kilometres of the sun in 1976.
Heat shields have come a long way since then, with the Solar Probe Plus boasting an 11.43 centimetres-thick heat shield to protect it from temperatures of up to 1,400 degrees Celsius. The shields should keep the probe's payload near room temperature, even in the fierce heat of the sun's corona.
"It's not that unusual a set of material, but it's thick enough to dissipate the energy," Delaney said of the probe's heat shield. "It will be the design of the spacecraft, more than the actual materials, that will play a pivotal role in protecting the instrument package over the seven-year lifetime of the mission."
NASA says the probe will face "heat and radiation unlike any spacecraft in history," while exploring the sun's outer atmosphere and collecting data that will shed new light on the physics of how stars work.
The probe is expected to reach the sun for the first time in early November, for the first of 24 orbits around the star. Seven of those orbits will include loops around Venus that are meant to narrow its orbit and bring it closer to the sun.
The final three orbits will take it closest to the sun, at which point it will be travelling at approximately 724,000 kilometres per hour. Each of these orbits is expected to take only 88 days – far fewer than the 365 days it takes for the Earth to go around the sun.
NASA says the Solar Plus Probe will go "close enough to the sun to watch the solar wind speed up from subsonic to supersonic, and it will fly through the birthplace of the highest-energy solar particles."
The spacecraft is expected to make its final pass around the sun in June 2025.