The facts are about the only thing on the Parker Solar Probe that will be cool. Temperatures reaching 2,500 degrees Fahrenheit will bake the carbon-shield protecting the rest of the spacecraft.
NASA is set to make an announcement about the Parker Solar Probe mission tomorrow, but we already know a lot about the spacecraft and its mission.
The Parker Solar Probe mission objectives
NASA’s is hammering home how the Parker Solar Probe will “revolutionize our understanding of the sun.” But what does that mean exactly? The mission has three primary science objectives.
– Trace the flow of energy that heats and accelerates the solar corona and solar wind.
– Determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind.
– Explore mechanisms that accelerate and transport energetic particles.
UPDATE: NASA renamed the mission Parker Solar Probe (was Solar Probe Plus) in honor of astrophysicist Eugene Parker. It marks the first time a spacecraft has been named for a living individual. I’ve updated the article to reflect the name change
Nearly 60 years ago, Parker published an article titled ‘Dynamics of the interplanetary gas and magnetic fields.’ In it, he talks about high speed matter and magnetism escaping the sun and affecting our entire solar system. Today, we know this phenomenon as the solar wind.
Learning more about our sun will also help us out when the sun decides to throw something nasty our way. A powerful enough solar flare from the sun could wreak havoc on power infrastructure on Earth. Areas without advance warning could go without power for months.
Understanding the inner workings of the sun’s corona will help scientists around the world better predict solar weather. Society today is much more susceptible to severe solar storms like the Carrington Event in 1859. That solar flare knocked out telegraph systems all over Europe and North America. And the auroras were so bright you could read a newspaper at night from the glow.
The data gathered over the nearly seven-year mission will help prepare us for the next inevitable Carrington Event.
Parker Solar Probe will become the fastest spacecraft ever built
During its closest approach (just 3.83 million miles), the Parker Solar Probe will be traveling at a blistering 450,000 (125 miles per second) miles per hour. It could go from Earth to the Moon in less than 30 minutes.
That will blow past the current record holder, Helios 2. It was also cruising around the sun in the 1970s, but only managed a top speed of 157,000 miles per hour (43 miles per second).
The trajectory and orbits
Parker Solar Probe begins its mission tentatively on July 31, 2018 when it launches. Two months later, it soars past Venus for its first of seven gravity assist flybys. These flybys help the spacecraft tighten its orbit to come as close as 3.9 million miles to the sun.
Let’s put that into perspective. Mercury sits nearly 36 million miles away from the sun.
Parker Solar Probe will get Venus’ help seven times over the course of the seven-year mission (once a year). All total, the spacecraft will circle the sun 24 times in elliptical orbits. Here’s an image showing a basic look at the orbits.
The final three orbits will take the spacecraft within 3.9 million miles of the sun, and nearly seven times closer than the Helios spacecraft ever flown. While Parker Solar Probe’s solar shield is cooking at temperatures beyond 2,000 degrees Fahrenheit, the spacecraft’s instruments will be sitting at near room temperature.
“The spacecraft will fly close enough to the Sun to watch the solar wind speed up from subsonic to supersonic,” NASA says.
The most important piece is the solar shield. It’s made of carbon-composite and will be just 4.5 inches thick.
One obstacle engineers have to overcome is the solar panel array. They aren’t designed to handle the intense heat and radiation during the spacecraft’s closest approach. The Parker Solar Probe will be able to retract and extend its solar arrays as needed. Check out how it works below.
Pumped liquid coolant will keep the solar arrays below 120 degrees Celsius.
Four instruments will reveal answers to old questions and pose new ones as the spacecraft cruises around the sun.
The Fields Experiment (FIELDS) will grab direct measurements of electric and magnetic fields, absolute plasma density and more.
The Integrated Science Investigation of the Sun (ISoIS) will observe energetic electrons, protons and heavy ions and match them up with the solar wind and coronal structures.
The Wide-field Imager for Solar PRobe (WISPR) is for all the space fans who like stunning images. It will snap images of the solar corona, inner heliosphere, solar wind and more.
And the Solar Wind Electrons Alphas and Protons (SWEAP) will tally up the most abundant particles in the solar wind and measure a variety of properties including temperature and velocity.
Data from these four instruments will be beamed back to Earth at just 167 kb/s.
Launch and first perihelion
Right now, the launch window is set for July 31 – August 19, 2018. A Delta IV-Heavy will get the Parker Solar Probe off Earth and started on its journey to the Sun. Here’s a Delta IV-Heavy launch from last year.
The first Venus flyby is set for September 28, 2018. About a month later, the spacecraft will hit its first perihelion (closest point to the sun). It’ll be the last three orbits that bring the Parker Solar Probe to its closest point around the sun. The first of those will be on December 19, 2024.
“Parker Solar Probe is going to answer questions about solar physics that we’ve over for more than six decades,” said Parker Solar Probe project scientist Nicola Fox. “It’s a spacecraft loaded with technological breakthroughs that will solve many of the largest mysteries about our star, including finding out why the sun’s corona is so much hotter than its surface. And we’re very proud to be able to carry Gene’s name with us on this amazing voyage of discovery.”
NASA is set to talk more about the mission at an event tomorrow (May 31). I’ll update this post with any new information we learn.
Image credits: NASA