Touchthesun - Blog Posts

Tools of the Trade: How Parker Solar Probe Will Study the Sun

Our Parker Solar Probe will get closer to the Sun than any spacecraft has ever gone – it will fly right through the Sun's corona, part of the Sun's atmosphere.

This spacecraft is full of cutting-edge technology, from its heat shield down to its guidance and control systems. It also carries four suites of advanced instruments designed to study the Sun in a multitude of ways.  

1. Measuring particles

Two of Parker Solar Probe's instrument suites are focused on measuring particles – electrons and ions – within the corona.

One of these particle-measuring instrument suites is SWEAP (Solar Wind Electrons Alphas and Protons). SWEAP counts the most common particles in the solar wind – the Sun's constant outflow of material – and measures their properties, like velocity, density and temperature. Gathering this information about solar wind particles will help scientists better understand why the solar wind reaches supersonic speeds and exactly which part of the Sun the particles come from.

One instrument in the SWEAP suite is the Solar Probe Cup. Most of the instruments on Parker Solar Probe stay safe and cool in the shadow of the heat shield, but the Solar Probe Cup is one of the few that sticks out. That's so it can capture and measure particles streaming straight out from the Sun, and it had to go through some intense testing to get ready for this position in the Sun's incredibly hot corona.  

Credit: Levi Hutmacher/Michigan Engineering

The ISʘIS suite (pronounced EE-sis, and including the symbol for the Sun in its acronym) also measures particles. ISʘIS is short for Integrated Science Investigation of the Sun, and this instrument suite measures particles that move faster – and therefore have more energy – than the solar wind.

These measurements will help scientists understand these particles' lifecycles – where they came from, how they got to be traveling so fast (these particles can reach speeds more than half the speed of light!) and what path they take as they travel away from the Sun and into interplanetary space.

2. Taking pictures – but not of the Sun's surface.

WISPR (Wide-Field Imager for Parker Solar Probe) has the only two cameras on Parker Solar Probe – but they're not pointed directly at the Sun. Instead, WISPR looks out the side of the spacecraft, in the direction it's traveling, looking at the space Parker Solar Probe is about to fly through. From that vantage point, WISPR captures images of structures within the corona like coronal mass ejections, or CMEs. CMEs are clouds of solar material that occasionally explode from the Sun at millions of miles per hour. Because this solar material is magnetized, CMEs can trigger geomagnetic storms when they reach Earth – which, in turn, can cause effects like auroras and even, in extreme cases, power outages.  

Right now, our observations of events like these come from satellites orbiting near Earth, so WISPR will give us a whole new perspective. And, scientists will be able to combine WISPR's images with Parker Solar Probe's direct particle measurements to get a better idea of how these structures change as they travel.

3. Studying electric & magnetic fields

The FIELDS instrument suite is appropriately named: It's what scientists will use to study the electric and magnetic fields in the corona.

Electric and magnetic fields are key to understanding what happens, not only on the Sun, but throughout space, because they are the primary driver accelerating charged particles. In particular, a process called magnetic reconnection – when magnetic field lines explosively realign, sending particles rocketing away at incredible speeds – is thought to drive solar explosions, as well as space weather effects on Earth, like the aurora.

FIELDS measures electric and magnetic field at high time resolution, meaning it takes lots of measurements in a short amount of time, to track these processes and shed some light on the mechanics underlying the Sun's behavior. FIELDS' measurements are precisely synced up with those of the SWEAP suite (one of the sets of instruments studying particles) so that scientists can match up the immediate effects that electric and magnetic fields have on the material of the solar wind.

Parker Solar Probe launches summer 2018 on its mission to study the Sun. Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

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Meet Parker Solar Probe, Our Mission to Touch the Sun

In just a few weeks, we're launching a spacecraft to get closer to the Sun than any human-made object has ever gone.

The mission, called Parker Solar Probe, is outfitted with a lineup of instruments to measure the Sun's particles, magnetic and electric fields, solar wind and more – all to help us better understand our star, and, by extension, stars everywhere in the universe.

Parker Solar Probe is about the size of a small car, and after launch – scheduled for no earlier than Aug. 6, 2018 – it will swing by Venus on its way to the Sun, using a maneuver called a gravity assist to draw its orbit closer to our star. Just three months after launch, Parker Solar Probe will make its first close approach to the Sun – the first of 24 throughout its seven-year mission.

Though Parker Solar Probe will get closer and closer to the Sun with each orbit, the first approach will already place the spacecraft as the closest-ever human-made object to the Sun, swinging by at 15 million miles from its surface. This distance places it well within the corona, a region of the Sun's outer atmosphere that scientists think holds clues to some of the Sun's fundamental physics.

For comparison, Mercury orbits at about 36 million miles from the Sun, and the previous record holder – Helios 2, in 1976 – came within 27 million miles of the solar surface. 

Humanity has studied the Sun for thousands of years, and our modern understanding of the Sun was revolutionized some 60 years ago with the start of the Space Age. We've come to understand that the Sun affects Earth in more ways than just providing heat and light – it's an active and dynamic star that releases solar storms that influence Earth and other worlds throughout the solar system. The Sun's activity can trigger the aurora, cause satellite and communications disruptions, and even – in extreme cases – lead to power outages.

Much of the Sun's influence on us is embedded in the solar wind, the Sun's constant outflow of magnetized material that can interact with Earth's magnetic field. One of the earliest papers theorizing the solar wind was written by Dr. Gene Parker, after whom the mission is named.

Though we understand the Sun better than we ever have before, there are still big questions left to be answered, and that's where scientists hope Parker Solar Probe will help.  

First, there's the coronal heating problem. This refers to the counterintuitive truth that the Sun's atmosphere – the corona – is much, much hotter than its surface, even though the surface is millions of miles closer to the Sun's energy source at its core. Scientists hope Parker Solar Probe's in situ and remote measurements will help uncover the mechanism that carries so much energy up into the upper atmosphere.

Second, scientists hope to better understand the solar wind. At some point on its journey from the Sun out into space, the solar wind is accelerated to supersonic speeds and heated to extraordinary temperatures. Right now, we measure solar wind primarily with a group of satellites clustered around Lagrange point 1, a spot in space between the Sun and Earth some 1 million miles from us. 

By the time the solar wind reaches these satellites, it has traveled about 92 million miles already, blending together the signatures that could shed light on the acceleration process. Parker Solar Probe, on the other hand, will make similar measurements less than 4 million miles from the solar surface – much closer to the solar wind's origin point and the regions of interest.

Scientists also hope that Parker Solar Probe will uncover the mechanisms at work behind the acceleration of solar energetic particles, which can reach speeds more than half as fast as the speed of light as they rocket away from the Sun! Such particles can interfere with satellite electronics, especially for satellites outside of Earth's magnetic field.

Parker Solar Probe will launch from Space Launch Complex 37 at Cape Canaveral Air Force Station, adjacent to NASA’s Kennedy Space Center in Florida. Because of the enormous speed required to achieve its solar orbit, the spacecraft will launch on a United Launch Alliance Delta IV Heavy, one of the most powerful rockets in the world.

Stay tuned over the next few weeks to learn more about Parker Solar Probe's science and follow along with its journey to launch. We'll be posting updates here on Tumblr, on Twitter and Facebook, and at nasa.gov/solarprobe.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com