At 3:31AM on Sunday, NASA will attempt to launch an unmanned spacecraft which will go closer to the sun than any rocket before it ever has. NASA is bragging that the craft, known as the Parker Probe, will actually “touch the sun.” Now technically, the spacecraft won’t actually touch the surface of the sun; it will remain about 4 million miles away from the sun’s surface. But the probe will pass through the sun’s outer atmosphere, which will allow it to gather more information about the sun than we’ve ever had access to before.
1. NASA Will Livestream the Parker Solar Probe Launch Beginning at 3AM
You can watch a livestream of the launch here. The probe will attempt to blast off from Cape Canaveral Air Force Station in Florida at 3:31AM on Sunday morning (or late, late Saturday night, depending on your point of view). NASA’s broadcast starts at 3AM.
Bear in mind that this will be NASA’s second attempt to launch the Parker Probe, and there is no guarantee that it will succeed. The first launch attempt was on Saturday night, also at 3:30AM. But due to technical difficulties that took longer than expected to resolve, the spacecraft could not take off in the launch window. The blast-off was rescheduled for tonight. If it doesn’t work tonight, NASA will keep trying every day until August 23.
As of Saturday night, reports said weather conditions looked to be 70 percent favorable for a successful launch.
The probe isn’t heading straight for the sun. First, it will make a stop on Venus. That’s why it needs to take off so early in the morning; at 3:30AM, the launchpad is pointed in the right direction to get to Venus. That’s also why the deadline for the launch is August 23, since after August 23, Venus will move too far out of range for the spacecraft to reach it.
2. The Probe Will Collect Information About Solar Wind and Electrical and Magnetic Fields
The solar probe is expected to gather more information about the sun than we’ve ever had access to before. It will pass through the sun’s outer atmosphere, or corona, taking photographs, measuring electrical and magnetic fields, and studying the make-up of solar wind.
Solar wind is a steady stream of plasma and particles moving away from the sun and into outer space. Scientists are particularly interested in learning more about solar wind because of its impact on earth. Solar wind carries charged particles and magnetic clouds away from the sun, and some of it reaches as far as the earth’s atmosphere. The Earth’s magnetic field protects our planet — but the solar wind, and the particles that are carried along in it, still interact with our atmosphere in surprising ways — solar wind, for example, is thought to cause the phenomenon of “northern lights,” or “aurora borealis.
You can read more about solar wind and its impact on the Earth here.
3. The Probe Is Named After The Scientist Who First Discovered Solar Wind — But Whose Ideas Weren’t Accepted For Years
Eugene Parker was an astronomer at the University of Chicago in the 1950s. In 1958, Parker published a paper where he set out the idea of solar wind. Parker was the first person to suggest that particles were constantly streaming off of the sun. Parker compared the phenomenon to the way water spray in a fountain.
Parker’s colleagues initially dismissed his ideas as “ludicrous.” Most astronomers at that time thought of outer space as perfectly empty and bare, and the notion of solar wind sweeping particles through space didn’t make sense to many people. It wasn’t until four years later, when a spacecraft bound for Venus found traces of energized particles streaming through space, that Parker’s theory started to gain acceptance.
The Parker solar probe is named after Eugene Parker, in recognition of his contribution to the study of the sun and of solar wind in particular. Spacecrafts aren’t normally named after living people, but astrophysicists say that Parker is a “celebrity” in the field.
4. Scientists Say the Probe’s State of the Art Thermal Protection System Will Protect It From the Sun’s Heat
The Parker Solar Probe will pass right through the sun’s corona, where it will be within 4 million miles of the sun’s surface. That may sound like a lot of distance, but the corona of the sun is hotter than the surface of the sun itself; its temperature is measured in the millions of degrees.
So how will the probe make it to the corona without being fried to a crisp immediately? Scientists say that it has a thermal protection system which can maintain the probe at just 85 degrees, even as it passes through the corona. You can watch a demonstration of that technology here. And you can read an explanation of why the corona is so hot here.
5. If All Goes According to Plan, the Probe Will Blast Off on a United Launch Alliance Delta IV Heavy Rocket
The United Launch Alliance Delta IV Heavy rocket is one of the most powerful rockets in the world, designed and built by the United Launch Alliance.
You can see updates about the rocket, and find more information about its specifications, here.
That site describes the probe’s mission as follows:
“Parker Solar Probe is humanity’s first mission to the sun. After launch, it will orbit directly through the solar atmosphere – the corona – closer to the surface than any human-made object has ever gone. While facing brutal heat and radiation, the mission will reveal fundamental science behind what drives the solar wind, the constant outpouring of material from the sun that shapes planetary atmospheres and affects space weather near Earth.
Parker Solar Probe is part of NASA’s Living With a Star Program to explore aspects of the connected sun-Earth system that directly affect life and society.”