NASA is sending a spacecraft to get up close and personal with a star for the first time, and it’s going to have to go faster than any manmade object in history to get there.
The crazy journey starts early Saturday when the Parker Solar Probe is scheduled to launch from the Kennedy Space Center in Florida atop a United Launch Alliance Delta IV Heavy rocket. The ambitious mission hopes to solve some of the more baffling solar mysteries, like why the sun’s outlying corona is so much hotter than its surface and where the solar wind comes from.
But perhaps more important to everyday Earthlings, the data collected by the probe could improve how we predict space weather, which can interfere with the electronics and communications technology that our society increasingly depends on.
‘Our ability to forecast space weather is about as good as our weather forecasts were in the 1970s,’ Kristopher Klein, a co-investigator on the mission from the University of Arizona, said in a statement. ‘If you have a better understanding of the behavior of these solar energetic particles, then you can make better predictions about when to send astronauts to Mars or protect a satellite before it gets ripped apart by a radiation burst.’
Yes, there is a Parker
The Parker Solar Probe is the first NASA spacecraft with a living namesake, 91-year-old Eugene Parker, who’s credited with discovering the existence of the solar wind, or constant flow of charged particles that the sun sends into the solar system, in the 1950s.
‘Many of his colleagues thought he must be wrong, but when Mariner 2 was on the trip to Venus in 1962, it revealed that a supersonic wind was always present,’ says CalTech’s Ed Stone, the longtime project scientist for NASA’s Voyager mission who also worked with Parker at the University of Chicago in the 1960s.
Parker also predicted the solar wind creates a sort of bubble around the solar system that we now call the heliosphere.
‘In 2012, Voyager 1 finally left the bubble first predicted by Parker, entering interstellar space,’ Stone says.
With the extent of the solar wind proven and explored, the Parker Solar Probe will now try to trace it to its source.
How close it’ll get
To see the sun at work, the spacecraft will fly within 4 million miles (6.4 million kilometers) of its surface, close enough for a good look but still far enough away to avoid burning up.
‘We’ll get close enough to where most of the mechanisms that are pushing the particles (that make up the solar wind) out are still actively doing that pushing,’ says Klein.
Instruments aboard the probe will attempt to record the particles in the solar wind being accelerated to supersonic speeds as they’re sent out into the solar system, where they create aurorae and other disturbances upon collision with earth’s magnetic field.
‘Plasma physics is really hard to study in the laboratory,’ explained prinicipal investigator and University of California, Berkeley professor Stuart Bale, in a statement. ‘Sticking a spacecraft right in the hot plasma makes an ideal laboratory.’
Plasma is the name given to a fourth state of matter that is basically super-heated gas (including the particles of the solar wind) present in space, which is what the probe will be cruising around in.
Scientists also hope that coming in close contact with our star will help solve the mystery of why its corona reaches temperatures over 2 million degrees Fahrenheit (1.1 million Celsius) but the Sun’s surface is only 9,000 degrees (6,000 Celsius). Instruments on board the probe have been designed to test a few popular hypotheses behind this odd superheating effect.
Others hope that insights gleaned from high-fiving the sun could have more practical implications on Earth for things like the development of fusion energy.
‘The plasma inside these magnetic bottles behaves a lot like the solar wind,’ Klein says. ‘Learning how we can control it in confinement is crucial.’
When it’ll get there
To get close to the sun, the Parker Solar Probe will travel very fast. At top speed, when it’s nearest the sun, it’ll be moving at 430,000 miles per hour (700,000 km/h) and will reach the star by November, just three months after launch.
‘In early December, I am counting on having that first pass of data at 35 solar radii, and I am sure it will be revolutionary. There will be great new stuff in there, from what we know about previous missions,’ Bale said.
Over its 7-year mission, the spacecraft will move ever closer to the surface of the sun, looping its way around Venus several times and coming near Earth’s orbit occasionally over the course of 25 solar orbits. But project scientist Nicola Fox told reporters at a press conference Thursday that it’ll already be pretty close on its first pass.
‘Even on our first fly-by we will be well within the solar corona,’ she said.
In addition to lots of high-tech instrumentation to gather data, Parker is also carrying a memory card with the names of 1.1 million people who submitted them to NASA to go along for the historic ride.
To keep all those names and some very expensive equipment from simply roasting like a marshmallow touching a campfire flame, the probe is equipped with an actively cooled carbon heat shield. Made from advanced materials, the shield is only about 4 inches (10 cm) thick and will keep instruments at around 85 degrees F (29 C), even when temperatures reach 2,500 F (1,371 C) on the sun-facing side.
How to watch the launch
After a few delays, the Parker Solar Probe now looks ready to launch from Kennedy Space Center’s Space Launch Complex-37 at 3:33 a.m. ET Saturday, weather permitting.