Parker Solar Probe

Humanity’s First Visit to a Star

Launched: August 12, 2018 at 3:31am EDT

Launch Site: NASA’s Kennedy Space Center, Florida

Launch Vehicle: Delta IV-Heavy with Upper Stage

We’ve been studying the Sun for decades, and now we’re finally going to go where the action is!

Parker Solar Probe’s primary science goal is to trace how energy flows through the corona, the outermost layer of the sun’s atmosphere.

The First Mission to Touch the Nearest Star

Parker Solar Probe will be a historic mission, flying into the Sun’s atmosphere (or corona) for the first time.

The corona is the sun’s outer atmosphere and a constant source of curiosity for scientists who study our star. The corona is hundreds of times hotter than the sun’s surface. This is contrary to our normal experience – that it’s cooler further away from a source of heat – so it poses a mystery for solar scientists. The corona is also where magnetic, energetic solar material is accelerated out into space in a non-stop flow called the solar wind.

Launching in 2018, Parker Solar Probe will fly through the corona, closer to the sun’s surface than any other spacecraft to date. Scientists hope this data will help them understand how heat and energy move through the corona and drive the solar wind, which can cause space weather here on Earth. Parker Solar Probe will make two dozen close approaches to the sun over its seven-year mission.

NASA named this mission in honor of Eugene Parker, a solar astrophysicist who revolutionized our understanding of how the sun’s emissions affect our solar system.

Coming closer to the Sun than any previous spacecraft, Parker Solar Probe will employ a combination of in situ measurements and imaging to achieve the mission’s primary scientific goal: to understand how the Sun’s corona is heated and how the solar wind is accelerated. Parker Solar Probe will revolutionize our knowledge of the origin and evolution of the solar wind.

(CREDIT: NASA’s Scientific Visualization Studio and Johns Hopkins University Applied Physics Laboratory)


Parker Solar Probe
Eugene Parker
Eugene Parker. CREDIT: University of Chicago
  • On the final three orbits, Parker Solar Probe will fly to within 8.5 solar radii of the Sun’s “surface” 8.5 solar radii is 8.5 times the radius of the Sun, or about 3.7 million miles. That is about seven times closer than the current record-holder for a close solar pass, the Helios spacecraft.
  • At closest approach, Parker Solar Probe will be hurtling around the Sun at approximately 450,000 miles per hour! That’s fast enough to get from Philadelphia to Washington, D.C., in one second.
  • Parker Solar Probe will pass Venus less than two months after launch and will be collecting science data at its first solar pass just one month later.
  • At closest approach to the Sun, while the front of Parker Solar Probe’s solar shield faces temperatures approaching 2,500° Fahrenheit (or about 1,400° Celsius), the spacecraft’s payload will be near room temperature.
  • Parker Solar Probe will orbit the Sun 24 times, gradually “walking in” toward the Sun with each pass. The closest points of each orbit come well within orbit of Mercury the closest planet to the Sun.

The first five new discoveries of Parker Solar Probe

Parker Solar Probe touches the Sun

Parker Solar Probe sees solar streamers

Hear about Parker Solar Probe from the Project Scientist, Dr. Nour Raouafi

Parker Solar Probe makes news discoveries about the planet Venus

Learn more about Parker Solar Probe & what it is studying:

Learn more about Parker by playing the videos below!

  • Videos will continue to play. Or jump to a specific video by clicking on the right icon [3 horizontal bars] to open up the playlist of 60+ videos!

Parker Solar Probe in the cleanroom
Parker Solar Probe in the cleanroom

Parker Solar Probe sits in a clean room on July 6, 2018, at Astrotech Space Operations in Titusville, Florida, after the installation of its heat shield. Credit: NASA/Johns Hopkins APL/Ed Whitman

SPACECRAFT – Extreme Engineering

NASA’s historic Parker Solar Probe (PSP) mission will revolutionize our understanding of the Sun. PSP will swoop closer to the Sun’s surface than any spacecraft before it, facing brutal heat and radiation conditions.

The spacecraft will come as close as 3.83 million miles (and 6.16 million kilometers) to the Sun, well within the orbit of Mercury and more than seven times closer than any spacecraft has come before.

To perform these unprecedented investigations, the spacecraft and instruments will be protected from the Sun’s heat by a 4.5-inch-thick (11.43 cm) carbon-composite shield, which will need to withstand temperatures outside the spacecraft that reach nearly 2,500 degrees Fahrenheit (1,377 degrees Celsius).

Concept of Operations
Concept of Operations
Anti-Ram Facing View
Anti-Ram Facing View
Ram Facing View


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 Parker Solar Probe to touch the sun.

The primary science goals for the mission are to trace the flow of energy and understand the heating of the solar corona and to explore what accelerates the solar wind. Parker Solar Probe provides a statistical survey of the outer corona.

There are four major investigations:

Fields Experiment (FIELDS)

This investigation will make direct measurements of electric and magnetic fields and waves, Poynting flux, absolute plasma density and electron temperature, spacecraft floating potential and density fluctuations, and radio emissions.

FIELDS PI: Prof. Stuart Bale; University of California, Berkeley

Fields Experiment (FIELDS)
Fields Experiment (FIELDS)

Integrated Science Investigation of the sun (IS☉IS)

This investigation makes observations of energetic electrons, protons and heavy ions that are accelerated to high energies (10s of keV to 100 MeV) in the sun’s atmosphere and inner heliosphere, and correlates them with solar wind and coronal structures.

IS☉IS PI: Dr. David McComas; Princeton University

Integrated Science Investigation of the sun (IS☉IS)

Wide-field Imager for Solar Probe (WISPR)

These telescopes will take images of the solar corona and inner heliosphere. The experiment will also provide images of the solar wind, shocks and other structures as they approach and pass the spacecraft. This investigation complements the other instruments on the spacecraft providing direct measurements by imaging the plasma the other instruments sample.

WISPR PI: Dr. Russell Howard; Naval Research Laboratory, VIDEO CREDIT: NASA/JPL/WISPR Team

Wide-field Imager for Solar PRobe (WISPR)
Wide-field Imager for Solar PRobe (WISPR)

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation

This investigation will count the most abundant particles in the solar wind — electrons, protons and helium ions — and measure their properties such as velocity, density, and temperature.

SWEAP PI: Prof. Justin Kasper; University of Michigan/ Smithsonian Astrophysics Observatory

SPC instrument diagram
SPC instrument diagram
SPAN-A+ instrument diagram
SPAN-A+ instrument diagram
SPAN-B instrument diagram
SPAN-B instrument diagram

Parker Solar Probe will have 24 orbits around the Sun during its nominal mission.

The last 3, #22, #23, and #24 all being the closest approach to the Sun. The timeline below lists the perihelion of each orbit, which is the point in the orbit when Parker is closest to the Sun.


Parker Solar Probe Timeline

Event Type Date and Time (UT) Distance from Center of Sun Angle Between PSP and Earth at Closest Approach
Venus Flyby 1 Closest Approach 2018-10-03 at 08:44 0.7 au -14 degrees
Encounter 1 Perihelion 2018-11-06 at 03:27 0.17 au (35.6 RS) 103 degrees
Encounter 2 Perihelion 2019-04-04 at 22:39 0.17 au (35.6 RS) -48 degrees
Encounter 3 Perihelion 2019-09-01 at 17:50 0.17 au (35.6 RS) 168 degrees
Venus Flyby 2 Closest Approach 2019-12-26 at 18:14 0.7 au -99 degrees
Encounter 4 Perihelion 2020-01-29 at 09:37 0.13 au (27.8 RS) 25 degrees
Encounter 5 Perihelion 2020-06-07 at 08:23 0.13 au (27.8 RS) -103 degrees
Venus Flyby 3 Closest Approach 2020-07-11 0.7 au 23 degrees
Encounter 6 Perihelion 2020-09-27 at 09:16 0.09 au (20.3 RS) 143 degrees
Encounter 7 Perihelion 2021-01-17 at 17:40 0.09 au (20.3 RS) 30 degrees
Venus Flyby 4 Closest Approach 2021-02-20 0.7 au 160 degrees
Encounter 8 Perihelion 2021-04-29 at 08:48 0.074 au (15.9 RS) -76 degrees
Encounter 9 Perihelion 2021-08-09 at 19:11 0.074 au (15.9 RS) 174 degrees
Venus Flyby 5 Closest Approach 2021-10-16 0.7 au -50 degrees
Encounter 10 Perihelion 2021-11-21 at 08:23 0.062 au (13.3 RS) 87 degrees
Encounter 11 Perihelion 2022-02-25 at 15:38 0.062 au (13.3 RS) -11 degrees
Encounter 12 Perihelion 2022-06-01 at 22:51 0.062 au (13.3 RS) -106 degrees
Encounter 13 Perihelion 2022-09-06 at 06:04 0.062 au (13.3 RS) 162 degrees
Encounter 14 Perihelion 2022-12-11 at 13:16 0.062 au (13.3 RS) 66 degrees
Encounter 15 Perihelion 2023-03-17 at 20:30 0.062 au (13.3 RS) -31 degrees
Encounter 16 Perihelion 2023-06-22 at 03:46 0.062 au (13.3 RS) -125 degrees
Venus Flyby 6 Closest Approach 2023-08-21 0.7 au 5 degrees
Encounter 17 Perihelion 2023-09-27 at 23:28 0.053 au (11.4 RS) 144 degrees
Encounter 18 Perihelion 2023-12-29 at 00:54 0.053 au (11.4 RS) 51 degrees
Encounter 19 Perihelion 2024-03-30 at 02:20 0.053 au (11.4 RS) -42 degrees
Encounter 20 Perihelion 2024-06-30 at 03:46 0.053 au (11.4 RS) -131 degrees
Encounter 21 Perihelion 2024-09-30 at 05:13 0.053 au (11.4 RS) 141 degrees
Venus Flyby 7 Closest Approach 2024-11-06 0.7 au -81 degrees
Encounter 22 Perihelion 2024-12-24 at 11:41 0.046 au (9.9 RS) 52 degrees
Encounter 23 Perihelion 2025-03-22 at 22:25 0.046 au (9.9 RS) -37 degrees
Encounter 24 Perihelion 2025-06-19 at 09:09 0.046 au (9.9 RS) -123 degrees


Parker Solar Probe Timeline


  • March: Critical Design Review (CDR)


  • May: System Integration Review
  • July: KDP-D
  • July: Start of Integration and Testing


  • Begin March 2017: Instrument Deliveries
  • Begin August 2017: Observatory System Testing
  • Fall 2017: Shipment of Observatory to GSFC


    • Spring 2018: Shipment of Observatory to Cape Canaveral
    • August 12, 2018: Launch


  • See table above

This summer, NASA is launching Parker Solar Probe, a mission to touch the Sun.

This spacecraft will fly closer to the Sun’s surface than any spacecraft before it, facing brutal heat and radiation. It will be the first spacecraft to fly directly through the Sun’s corona – the part of the solar atmosphere visible during an eclipse – to answer questions about solar physics that have puzzled scientists for more than six decades.

Gathering information about fundamental processes near the Sun can help improve our understanding of how the Sun changes our space environment – such space weather can affect astronauts, interfere with the orbits of satellites, or damage onboard electronics.

Parker Solar Probe’s launch is targeted for August 6–19, 2018.

Join us live to get a deep dive on the science and engineering of this stellar mission. We’ll also be answering your #askNASA questions!

Participating live are:

Parker Solar Probe
Parker Solar Probe’s primary science goal is to trace how energy flows through the corona, the outermost layer of the sun’s atmosphere.
Venus Fly By
To reach the sun, Parker Solar Probe's path uses seven gravity assists from Venus to propel it closer to the star.
Parker Solar Probe
A 4.5-inch-thick carbon-composite shield will keep Parker Solar Probe’s instruments at room temperature as the spacecraft approaches the sun.

CREDIT: NASA’s Scientific Visualization Studio and Johns Hopkins University Applied Physics Laboratory.

Parker Solar Probe - Korean
Can anyone translate this Korean cartoon?

First Discoveries of Parker Solar Probe

On December 4, 2019, a series of 4 papers highlighting some of the first results from NASA’s Parker Solar Probe were released. NASA released a short trailer from the key scientists.

Then it released a video discussing the 5 key results from the papers:

These results are from the first 3 of 24 orbits so there will be a lot more to come. The papers are published online in Nature:

On December 11th, another press conference was given at the 2019 Fall meeting of the American Geophysical Union in San Francisco. The results from the Nature papers were presented again along with a non-solar result, Parker Solar Probe’s discovery of a dust trail belonging to the asteroid Phaethon, which gives us the Geminids meteor shower every year on Earth.

First Whispers of the SOLAR WIND’S BIRTH

Scientists have studied the solar wind for more than 60 years, but they’re still puzzled over some of its behaviors. NASA’s Parker Solar Probe — designed and built by APL — hears the small chirps, squeaks and rustles that hint at the origin of this mysterious and ever-present wind. And now the Parker Solar Probe team is getting their first chance to hear them, too.

Parker Solar Probe’s FIELDS instrument can eavesdrop on the electric and magnetic fluctuations caused by plasma waves, and it can “hear” when the waves and particles interact with one another, recording frequency and amplitude information about these plasma waves that scientists can transform into sound files.

Credit: NASA/Johns Hopkins APL


Solar Orbiter +
Parker Solar Probe