Parker Solar Probe

The Parker Solar Probe concept originates in the 1958 report by the Fields and Particles Group, Committee 8 of the National Academy of Sciences' Space Science Board,{{cite book|title=First Among Equals: The Selection of NASA Space Science Experiments|chapter=3.2.2: Physics of Fields and Particles in Space|first=John E.|last=Naugle|series=The NASA History Series|year=1991|page=34|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910018746.pdf#page=49|chapter-url=https://history.nasa.gov/SP-4215/ch3-2.html#3.2.2|lccn=91-13286|id=NASA SP-4215|access-date=February 11, 2020|archive-date=July 29, 2020|archive-url=https://web.archive.org/web/20200729104156/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910018746.pdf#page=49|url-status=live}} {{PD-notice}}{{cite press release|title=National Academy of Sciences Establishes Space Science Board|date=August 3, 1958|first=Detlev W.|last=Bronk|author-link=Detlev Bronk|publisher=National Academy of Sciences; National Research Council|url=https://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_052237.pdf|access-date=February 11, 2020|archive-date=March 3, 2019|archive-url=https://web.archive.org/web/20190303100301/http://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_052237.pdf|url-status=live}} {{PD-notice}}{{cite journal |last1=Guo |first1=Yanping |last2=Thompson |first2=Paul |last3=Wirzburger |first3=John |last4=Pinkine |first4=Nick |last5=Bushman |first5=Stewart |last6=Goodson |first6=Troy |last7=Haw |first7=Rob |last8=Hudson |first8=James |last9=Jones |first9=Drew |last10=Kijewski |first10=Seth |last11=Lathrop |first11=Brian |last12=Lau |first12=Eunice |last13=Mottinger |first13=Neil |last14=Ryne |first14=Mark |last15=Shyong |first15=Wen-Jong |last16=Valerino |first16=Powtawche |last17=Whittenburg |first17=Karl |title=Execution of Parker Solar Probe's unprecedented flight to the Sun and early results |journal=Acta Astronautica |date=February 2021 |volume=179 |pages=425–438 |doi=10.1016/j.actaastro.2020.11.007|doi-access=free |bibcode=2021AcAau.179..425G }} which proposed several space missions including "a solar probe to pass inside the orbit of Mercury to study the particles and fields in the vicinity of the Sun".{{cite conference|title=Solar Probe Plus: A Scientific Investigation Sixty Years in the Making|first=Ralph L. Jr.|last=McNutt|date=December 15, 2015|conference=American Geophysical Union Fall Meeting|bibcode=2015AGUFMSH24A..01M|url=https://agu.confex.com/agu/fm15/webprogram/Paper61485.html|access-date=February 11, 2020|archive-date=September 25, 2021|archive-url=https://web.archive.org/web/20210925002929/https://agu.confex.com/agu/fm15/webprogram/Paper61485.html|url-status=live}}{{cite news|title=A 60-year race to touch the Sun|first=Ian|last=Graber-Stiehl|date=August 13, 2018|journal=Astronomy|url=http://astronomy.com/news/2018/08/60-year-race-to-the-sun|access-date=February 11, 2020|archive-date=January 24, 2020|archive-url=https://web.archive.org/web/20200124144616/http://www.astronomy.com/news/2018/08/60-year-race-to-the-sun|url-status=live}}

Studies in the 1970s and 1980s reaffirmed its importance,{{r|McNutt}} but it was always postponed due to cost. A cost-reduced Solar Orbiter mission was studied in the 1990s, and a more capable Solar Probe mission served as one of the centerpieces of the Outer Planet/Solar Probe (OPSP) program formulated by NASA in the late 1990s. The first three missions of the program were planned to be: the Solar Orbiter, the Pluto and Kuiper belt reconnaissance Pluto Kuiper Express mission, and the Europa Orbiter astrobiology mission focused on Europa.{{cite press release |title=McNamee Chosen to Head NASA's Outer Planets/Solar Probe Projects|url=http://www.jpl.nasa.gov/news/news.php?feature=5174|publisher=Jet Propulsion Laboratory|access-date=January 2, 2017|archive-url=https://web.archive.org/web/20170102204522/http://www.jpl.nasa.gov/news/news.php?feature=5174|archive-date=January 2, 2017|date=April 15, 1998|url-status=live}}{{cite conference|last1=Maddock|first1=Robert W.|last2=Clark|first2=Karla B.|last3=Henry|first3=Curt A.|last4=Hoffman|first4=Pamela J.|title=The Outer Planets/Solar Probe Project: "Between an ocean, a rock, and a hot place"|url=https://trs.jpl.nasa.gov/bitstream/handle/2014/20792/98-1875.pdf|conference=1999 IEEE Aerospace Conference|date=March 7, 1999|bibcode=1999aero....1..383M|access-date=August 12, 2018|archive-date=May 11, 2019|archive-url=https://web.archive.org/web/20190511123116/https://trs.jpl.nasa.gov/bitstream/handle/2014/20792/98-1875.pdf|url-status=live}}

File:Evolution of PSP design.jpg

The original Solar Probe design used a gravity assist from Jupiter to enter a polar orbit which dropped almost directly toward the Sun. While this explored the important solar poles and came even closer to the surface (3 {{solar radius}}, a perihelion of 4 {{solar radius}}),{{r|opsp}} the extreme variation in solar irradiance made for an expensive mission and required a radioisotope thermal generator for power. The trip to Jupiter also made for a long mission, {{frac|3|1|2}} years to first solar perihelion, 8 years to second.

Following the appointment of Sean O'Keefe as Administrator of NASA, the entirety of the OPSP program was canceled as part of President George W. Bush's request for the 2003 United States federal budget.{{cite web|last1=Berger|first1=Brian|title=NASA Kills Europa Orbiter; Revamps Planetary Exploration |url=http://www.space.com/news/nasa_budget_020204.html|website=space.com|publisher=Purch Group|access-date=January 2, 2017|archive-url=https://web.archive.org/web/20020210015816/http://www.space.com/news/nasa_budget_020204.html|archive-date=February 10, 2002|date=February 4, 2002|url-status=dead}} Administrator O'Keefe cited a need for a restructuring of NASA and its projects, falling in line with the Bush Administration's wish for NASA to refocus on "research and development, and addressing management shortcomings".

In the early 2010s, plans for the Solar Probe mission were incorporated into a lower-cost Solar Probe Plus.{{cite web|last1=Fazekas|first1=Andrew|title=New NASA Probe to Dive-bomb the Sun |url=https://news.nationalgeographic.com/news/2010/09/100909-science-space-sun-new-nasa-solar-probe-plus-dive-bomb/|website=National Geographic|publisher=21st Century Fox/National Geographic Society|access-date=January 2, 2017|archive-url=https://web.archive.org/web/20170102202026/http://news.nationalgeographic.com/news/2010/09/100909-science-space-sun-new-nasa-solar-probe-plus-dive-bomb/|archive-date=January 2, 2017|url-status=dead|date=September 10, 2010}} The redesigned mission uses multiple Venus gravity assists for a more direct flight path, which can be powered by solar panels. It has a higher perihelion, reducing the demands on the thermal protection system.

In May 2017, the spacecraft was renamed the Parker Solar Probe in honor of astrophysicist Eugene Newman Parker,{{cite news|last=Chang|first=Kenneth|title=NASA's Parker Solar Probe Is Named for Him. 60 Years Ago, No One Believed His Ideas About the Sun|url=https://www.nytimes.com/2018/08/10/science/eugene-parker-solar-wind-nasa-probe.html|date=August 10, 2018|work=The New York Times|access-date=January 16, 2024|archive-date=August 11, 2018|archive-url=https://web.archive.org/web/20180811211441/https://www.nytimes.com/2018/08/10/science/eugene-parker-solar-wind-nasa-probe.html|url-status=live|quote=It is the Parker Solar Probe, named after Dr. Parker, now 91 years old. It is the first time that NASA has named a mission for a living person.}}{{cite news|url=https://www.wired.co.uk/article/nasa-sun-mission-parker-solar-probe|title=Nasa's mission to Sun renamed after astrophysicist behind solar wind theory|last=Burgess|first=Matt|magazine=Wired|date=May 31, 2017|access-date=January 1, 2018|archive-date=November 25, 2020|archive-url=https://web.archive.org/web/20201125060335/https://www.wired.co.uk/article/nasa-sun-mission-parker-solar-probe|url-status=live}} who had proposed the existence of nanoflares as an explanation of coronal heating{{Cite web |last=Chhabra |first=Sherry |date=2022-04-30 |title=Obituary: Eugene N. Parker (1927 - 2022) |url=https://solarnews.nso.edu/obituary-eugene-n-parker-1927-2022/ |access-date=2024-01-07 |website=SolarNews |language=en-US}} as well as having developed a mathematical theory that predicted the existence of solar wind.{{Cite web |date=2022-03-16 |title=Eugene Parker, 'legendary figure' in solar science and namesake of Parker Solar Probe, 1927-2022 {{!}} University of Chicago News |url=https://news.uchicago.edu/story/eugene-parker-legendary-figure-solar-science-and-namesake-parker-solar-probe-1927-2022 |access-date=2024-01-07 |website=news.uchicago.edu |language=en}} The solar probe cost NASA US$1.5 billion.[https://www.space.com/41424-parker-solar-probe-sun-science.html How NASA's New Solar Probe Will 'Touch' the Sun on Historic Mission] {{Webarchive|url=https://web.archive.org/web/20210127035614/https://www.space.com/41424-parker-solar-probe-sun-science.html |date=January 27, 2021 }}. Meghan Bartels, Space.com. August 9, 2018.[http://www.satnews.com/story.php?number=258258659&menu=2 Successful Launch of NASA's Parker Solar Probe.] {{Webarchive|url=https://web.archive.org/web/20190219093915/http://satnews.com/story.php?number=258258659&menu=2 |date=February 19, 2019 }} SatNews Daily. August 12, 2018. The launch rocket bore a dedication in memory of APL engineer Andrew A. Dantzler who had worked on the project.{{cite news|title=Parker Solar Probe Begins Mission on Rocket Dedicated to APL's Andy Dantzler|url=http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=102|publisher=The Johns Hopkins University Applied Physics Laboratory|date=September 26, 2018|access-date=December 3, 2018|archive-date=November 26, 2020|archive-url=https://web.archive.org/web/20201126174556/http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=102|url-status=live}}

A memory card containing names submitted by over 1.1 million people was mounted on a plaque and installed below the spacecraft's high-gain antenna.{{cite news |date=May 21, 2018 |title=More Than 1.1 Million Names Installed on NASA's Parker Solar Probe |url=https://www.nasa.gov/feature/goddard/2018/more-than-11-million-names-installed-on-nasa-s-parker-solar-probe |url-status=live |archive-url=https://web.archive.org/web/20211216041859/https://www.nasa.gov/feature/goddard/2018/more-than-11-million-names-installed-on-nasa-s-parker-solar-probe/ |archive-date=December 16, 2021 |access-date=December 17, 2021 |website=NASA}} The card also contains photos of Parker and a copy of his 1958 scientific paper predicting important aspects of solar physics.{{cite web |title=NASA Press Kit: Parker Solar Probe |url=https://directory.eoportal.org/web/eoportal/satellite-missions/p/psp |url-status=live |archive-url=https://web.archive.org/web/20170701232946/https://directory.eoportal.org/web/eoportal/satellite-missions/p/psp |archive-date=July 1, 2017 |access-date=August 15, 2018 |publisher=NASA}} {{PD-notice}}

The Parker Solar Probe is the first spacecraft to fly into the low solar corona. It will assess the structure and dynamics of the Sun's coronal plasma and magnetic field, the energy flow that heats the solar corona and impels the solar wind, and the mechanisms that accelerate energetic particles.

The spacecraft's systems are protected from the extreme heat and radiation near the Sun by a solar shield. Incident solar radiation at perihelion is approximately {{val|{{#expr:475*1.361 round -1}}|u=kW |up=m2}}, or 475 times the intensity at Earth orbit.{{r|extreme|Fox 2016|p2=31}} The solar shield is hexagonal, mounted on the Sun-facing side of the spacecraft, {{cvt|2.3|m}} in diameter,{{r|jhuapl}} {{cvt|11.4|cm}} thick, and is made of two panels of reinforced carbon–carbon composite with a lightweight {{convert|4.5|in|cm|disp=flip|sp=us|adj=mid|-thick}} carbon foam core,{{cite web |title=GMS: Cutting-Edge Heat Shield Installed on NASA's Parker Solar Probe |url=https://svs.gsfc.nasa.gov/12992 |website=svs.gsfc.nasa.gov |access-date=4 November 2022 |language=en |date=5 July 2018}} {{PD-notice}} which is designed to withstand temperatures outside the spacecraft of about {{cvt|2500|F|C|order=flip}}. The shield weighs only {{convert|160|lbs|kg|order=flip}} and keeps the spacecraft's instruments at {{cvt|85|F|C|order=flip}}.

A white reflective alumina surface layer minimizes absorption. The spacecraft systems and scientific instruments are located in the central portion of the shield's shadow, where direct radiation from the Sun is fully blocked. If the shield was not between the spacecraft and the Sun, the probe would be damaged and become inoperative within tens of seconds. As radio communication with Earth takes about eight minutes in each direction, the Parker Solar Probe has to act autonomously and rapidly to protect itself. This is done using four light sensors to detect the first traces of direct sunlight coming from the shield limits and engaging movements from reaction wheels to reposition the spacecraft within the shadow again. According to project scientist Nicky Fox, the team described it as "the most autonomous spacecraft that has ever flown".{{r|bbc22jl18}}

The primary power for the mission is a dual system of solar panels (photovoltaic arrays). A primary photovoltaic array, used for the portion of the mission outside {{Val|0.25|u=au}}, is retracted behind the shadow shield during the close approach to the Sun, and a much smaller secondary array powers the spacecraft through closest approach. This secondary array uses pumped-fluid cooling to maintain operating temperature of the solar panels and instrumentation.{{cite conference|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090004577.pdf|title=Solar Power System Design for the Solar Probe+ Mission|conference=6th International Energy Conversion Engineering Conference|location=Cleveland, Ohio.|first1=Geoffrey A.|last1=Landis|first2=Paul C. |last2=Schmitz|first3=James|last3=Kinnison|first4=Martin|last4=Fraeman|first5=Lew|last5=Roufberg|first6=Steve|last6=Vernon|first7=Melissa|last7=Wirzburger|display-authors=1|date=July 28–30, 2008|id=AIAA 2008-5712|access-date=July 25, 2018|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111220403/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090004577.pdf|url-status=live}} {{PD-notice}}{{cite web|url=https://www.techexplorist.com/traveling-sun-parker-solar-probe-melt/15586/|title=Traveling to the Sun: Why won't Parker Solar Probe melt?|first=Pranjal|last=Mehar|website=Tech Explorist|date=July 20, 2018|access-date=August 15, 2018|archive-date=December 29, 2019|archive-url=https://web.archive.org/web/20191229084547/https://www.techexplorist.com/traveling-sun-parker-solar-probe-melt/15586/|url-status=live}}

File:KSC-20180605-PH GEB01 0116 (41073463690).jpg|A light bar testing in the Astrotech processing facility.

File:Parker Solar Probe mated.jpg|Parker Solar Probe mated to its third stage rocket motor

File:Parker Solar Probe.webm|PSP during extensive environmental testing.

File:Parker fairing.jpg|PSP encapsulated in fairing.

File:NASA's Parker Solar Probe Mission Launches to Touch the Sun.webm|The launch of the probe.

File:Animation of Parker Solar Probe trajectory.gif}}{{·}}{{legend2|Lime|Mercury}}{{·}}{{legend2|Cyan|Venus}}{{·}}{{legend2|RoyalBlue|Earth}}
For more detailed animation, see this video.]]

The Parker Solar Probe mission design used repeated gravity assists at Venus to incrementally decrease its orbital perihelion to achieve a final altitude (above the surface) of approximately 8.5 solar radii, or about {{cvt|6|e6km|e6mi+au|abbr=off}}.{{cite web|title=Solar Probe Plus: A NASA Mission to Touch the Sun|url=http://solarprobe.jhuapl.edu/|publisher=Johns Hopkins University Applied Physics Laboratory|date=September 4, 2010|access-date=September 30, 2010|archive-date=March 1, 2021|archive-url=https://web.archive.org/web/20210301043541/http://solarprobe.jhuapl.edu///|url-status=live}} The spacecraft trajectory included seven Venus flybys over nearly seven years to gradually shrink its elliptical orbit around the Sun, for a total of 24 orbits.{{r|extreme}} The near Sun radiation environment was predicted to cause spacecraft charging effects, radiation damage in materials and electronics, and communication interruptions, so the orbit is highly elliptical with short times spent near the Sun.{{r|Fox 2016}}

The trajectory required high launch energy, so the probe was launched on a Delta IV Heavy launch vehicle and an upper stage based on the Star 48BV solid rocket motor.{{r|Fox 2016}} Interplanetary gravity assists provided further deceleration relative to its heliocentric orbit, which resulted in a heliocentric speed record at perihelion.{{r|Delta 4}}{{cite web |last1=Scharf |first1=Caleb A. |title=The Fastest Spacecraft Ever? |url=https://blogs.scientificamerican.com/life-unbounded/the-fastest-spacecraft-ever/ |website=Scientific American Blog Network |access-date=July 21, 2017 |archive-date=December 27, 2021 |archive-url=https://web.archive.org/web/20211227074426/https://blogs.scientificamerican.com/life-unbounded/the-fastest-spacecraft-ever/ |url-status=live}} As the probe passed around the Sun in December 2024, it achieved a velocity of {{convert|430000|mph|kph|abbr=on|order=flip}} or 191 km/s (118.7 mi/s) in the heliocentric ecliptic reference frame, which temporarily made it the fastest human-made object, almost three times as fast as the previous record holder, Helios-2.{{cite web|url=http://www.aerospaceweb.org/question/performance/q0023.shtml|title=Aircraft Speed Records|date=November 13, 2014|publisher=Aerospaceweb.org|access-date=March 7, 2017|archive-date=December 23, 2018|archive-url=https://web.archive.org/web/20181223182053/http://www.aerospaceweb.org/question/performance/q0023.shtml|url-status=live}}{{cite web|url=http://www.guinnessworldrecords.com/world-records/66135-fastest-spacecraft-speed|title=Fastest spacecraft speed|date=July 26, 2015|website=guinnessworldrecords.com |archive-url=https://web.archive.org/web/20161219024804/http://www.guinnessworldrecords.com/world-records/66135-fastest-spacecraft-speed|archive-date=December 19, 2016|url-status=dead}}{{Citation|title=Parker Solar Probe – Check123, Video Encyclopedia|url=https://www.check123.com/videos/13450-parker-solar-probe|access-date=June 1, 2017|archive-url=https://web.archive.org/web/20170810211059/https://www.check123.com/videos/13450-parker-solar-probe|archive-date=August 10, 2017|url-status=dead}}

Launch injection was very close to predictions, but nevertheless required path correction. Trajectory was re-optimized after the launch to save fuel. The first Venus flyby was only 52 days after the launch; three trajectory correction maneuvers were performed in this window.

As described by Kepler's laws of planetary motion, which apply to any object in an orbit, gravity will cause the spacecraft to accelerate as it nears perihelion, then slow down again afterward until it reaches its aphelion. Because of its highly elliptical orbit and the Sun's strong gravity, this effect is particularly pronounced for the Parker Solar Probe. During a perihelion on September 27, 2023, the spacecraft traveled at 394,736 miles per hour (176.5 km/s), fast enough to fly from New York to Tokyo in just over a minute.{{cite web |last1=Apodaca |first1=Desiree |title=For the Record: Parker Solar Probe Sets Distance, Speed Marks on 17th Swing by the Sun |url=https://blogs.nasa.gov/parkersolarprobe/2023/09/28/for-the-record-parker-solar-probe-sets-distance-speed-marks-on-17th-swing-by-the-sun/ |website=blogs.nasa.gov |access-date=2023-10-12 |date=2023-09-28}}

File:Sun's Apparent Size as Seen From Earth vs From Solar Probe Plus's orbit.png

The final gravity assist of the Parker Solar Probe mission occurred on November 6, 2024, which set the spacecraft on a new orbit passing 6.1 million kilometers (3.8 million miles) from the surface of the Sun.{{Cite press release |title=NASA's Sun-Bound Parker Solar Probe Swings Through Final Venus Flyby |publisher=Johns Hopkins University Applied Physics Laboratory |date=2024-11-08 |first=Mike |last=Buckley |url=https://www.jhuapl.edu/news/news-releases/241108-venus-gravity-assist-7 |access-date=2024-12-19 |language=en}} A beacon transmission was made and received successfully on December 20 to confirm that the craft was operating normally ahead of the perihelion. The exact time of closest approach was 11:53 UTC on December 24 but the craft was out of contact at this time. A further beacon transmission confirming successful passage was received on December 26.{{citation |date=2024-12-20 |title=Parker Solar Probe Begins Record-Setting Closest Approach to the Sun – Parker Solar Probe |url=https://blogs.nasa.gov/parkersolarprobe/2024/12/20/parker-solar-probe-begins-record-setting-closest-approach-to-the-sun/ |publisher=NASA |author1=Michael Buckley |author2=Abbey Interrante |language=en-US}}{{citation |author= |title=Nasa probe 'safe' after closest-ever approach to sun |date=2024-12-27 |newspaper=The Guardian

|agency=Reuters

|url=https://www.theguardian.com/science/2024/dec/27/nasa-probe-safe-parker-solar-spacecraft-closest-approach-sun |language=en-GB |issn=0261-3077}}

This final orbit is inside the orbit of Venus and so no further encounters with that planet are planned. It will continue in this orbit but requiring adjustment to maintain attitude so that its transmitters point at Earth. Eventually its thrusters will run out of fuel and full functioning will not then be possible. The plan is to then rotate the craft so that its instruments will be exposed to the full radiance of the Sun for the first time. This is expected to ablate and destroy them. The heat shield will remain though and is expected to continue to orbit the Sun for millions of years.{{citation |url=https://www.skyatnightmagazine.com/news/parker-solar-probe-closest-perihelion |title=The Parker Solar Probe passed closer to the Sun than any spacecraft ever before on Christmas Eve 2024 |magazine=Sky at Night |publisher=BBC |author=Ezzy Pearson |date=24 December 2024}}

File:Parker-Solar-Probe-Ram-Facing-View.png

File:Parker Solar Probe 3D model.stl

Parker Solar Probe has four main instruments:{{cite web |last1=Garner |first1=Rob |title=Parker Solar Probe Instruments |url=https://www.nasa.gov/content/goddard/parker-solar-probe-instruments |website=NASA |access-date=3 August 2022 |date=12 July 2018 |archive-date=August 11, 2018 |archive-url=https://web.archive.org/web/20180811133110/https://www.nasa.gov/content/goddard/parker-solar-probe-instruments/ |url-status=dead }}{{PD-notice}}{{cite web |title=Parker Solar Probe: Spacecraft |url=http://parkersolarprobe.jhuapl.edu/Spacecraft/index.php#Instruments |website=parkersolarprobe.jhuapl.edu |access-date=3 August 2022}}

• FIELDS (Electromagnetic Fields Investigation). The instrument suite captures the scale and shape of electric and magnetic fields in the Sun's atmosphere. FIELDS measures waves and turbulence in the inner heliosphere with high time resolution to understand the fields associated with waves, shocks and magnetic reconnection, a process by which magnetic field lines explosively realign. FIELDS measures the electric field around the spacecraft with five antennas, four of which stick out beyond the spacecraft's heat shield and into the sunlight, where they experience temperatures of {{convert|1370|C|F}}. The {{convert|2|m||adj=mid|-long|sp=us}} antennas are made of a niobium alloy, which can withstand extreme temperatures. FIELDS measures electric fields across a broad frequency range both directly and remotely. Operating in two modes, the four sunlit antennas measure the properties of the fast and slow solar wind — the flow of solar particles constantly streaming out from the Sun. The fifth antenna, which sticks out perpendicular to the others in the shade of the heat shield, helps make a three-dimensional picture of the electric field at higher frequencies. The suite also has three magnetometers to assess the magnetic field. A search coil magnetometer, or SCM, measures how the magnetic field changes over time. Two identical fluxgate magnetometers, MAGi and MAGo, measure the large-scale coronal magnetic field. The fluxgate magnetometers are specialized for measuring the magnetic field further from the Sun where it varies at a slower rate, while the search coil magnetometer is necessary closer to the Sun where the field changes quickly, as it can sample the magnetic field at a rate of two million times per second. The Principal Investigator is Stuart Bale at the University of California, Berkeley.
• IS☉IS (Integrated Science Investigation of the Sun). The instrument uses two complementary instruments to measure particles across a wide range of energies. By measuring electrons, protons and ions, IS☉IS will understand the particles' lifecycles — where they came from, how they became accelerated and how they move out from the Sun through interplanetary space. The two energetic particle instruments on IS☉IS are called EPI-Lo and EPI-Hi (EPI stands for Energetic Particle Instrument). EPI-Lo measures the spectra of electrons and ions and identifies carbon, oxygen, neon, magnesium, silicon, iron and two isotopes of helium, He-3 and He-4. Distinguishing between helium isotopes will help determine which of several theorized mechanisms caused the particles' acceleration. The instrument has a design with an octagonal dome body supporting 80 viewfinders. Multiple viewfinders provide a wide field of view to observe low-energy particles. An ion that enters EPI-Lo through one of the viewfinders first passes through two carbon-polyimide-aluminum foils and then encounters a solid-state detector. Upon impact, the foils produce electrons, which are measured by a microchannel plate. Using the amount of energy left by the ion's impact on the detector and the time it takes the ions to pass through the sensor identifies the species of the particles. EPI-Hi uses three particle sensors composed of stacked layers of detectors to measure particles with energies higher than those measured by EPI-Lo. The front few layers are composed of ultra-thin silicon detectors made up of geometric segments, which allows for the determination of the particle's direction and helps reduce background noise. Charged particles are identified by measuring how deep they travel into the stack of detectors and how many electrons they pull off atoms in each detector, a process called ionization. At closest approach to the Sun, EPI-Hi will be able to detect up to 100,000 particles per second. The Principal Investigator is David McComas at Princeton University.{{cite journal|last1=McComas|first1=D.J. |last2=Alexander|first2=N.|last3=Angold|first3=N.|last4=Bale|first4=S.|last5=Beebe|first5=C.|last6=Birdwell|first6=B.|last7=Boyle|first7=M.|last8=Burgum|first8=J. M.|last9=Burnham|first9=J. A.|last10=Christian |first10=E. R.|last11=Cook|first11=W. R. |last12=Cooper|first12=S. A.|last13=Cummings|first13=A. C.|last14=Davis|first14=A. J.|last15=Desai|first15=S. I.|last16=Dickinson |first16=J.|last17=Dirks|first17=G |last18=Do|first18=D. H.|last19=Fox|first19=N.|last20=Giacalone|first20=J.|last21=Gold|first21=R. E.|last22=Gurnee|first22=R. S.|last23=Hayes|first23=J. R.|last24=Hill|first24=M. E.|last25=Kasper|first25=J. C. |last26=Kecman|first26=B.|last27=Klemic |first27=J.|last28=Krimigis|first28=S. M.|last29=Labrador|first29=A. W.|last30=Layman|first30=R. S.|last31=Leske|first31=R. A.|last32=Livi|first32=S.|last33=Mathaeus |first33=W. H.|last34=McNutt Jr.|first34=R. L.|last35=Mewaldt|first35=R. A.|last36=Mitchell|first36=D. G.|last37=Nelson|first37=K.S.|last38=Parker|first38=C.|last39=Rankin|first39=J. S.|last40=Roelof|first40=E. C.|last41=Schwadron|first41=N. A.|last42=Seifert|first42=H.|last43=Shuman|first43=S.|last44=Stokes|first44=M. R.|last45=Stone|first45=E. C.|last46=Vandergriff|first46=J. D.|last47=Velli|first47=M.|last48=von Rosenvinge|first48=T. T.|last49=Weidner|first49=S. E.|last50=Wiedenbeck|first50=M. E.|last51=Wilson IV|first51=P.|date=December 2016|title=Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation|journal=Space Science Reviews|volume=204|issue=1–4|pages=187–156|display-authors=1|doi=10.1007/s11214-014-0059-1|bibcode=2016SSRv..204..187M|doi-access=free}}
• WISPR (Wide-field Imager for Solar Probe). These optical telescopes acquire images of the corona and inner heliosphere. WISPR uses two cameras with radiation-hardened Active Pixel Sensor CMOS detectors. The camera's lenses are made of a radiation hard BK7, a common type of glass used for space telescopes, which is also sufficiently hardened against the impacts of dust. The Principal Investigator is Russell Howard at the Naval Research Laboratory.
• SWEAP (Solar Wind Electrons Alphas and Protons). This investigation will count the electrons, protons and helium ions, and measure their properties such as velocity, density, and temperature. Its main instruments are the Solar Probe Analyzers (SPAN, two electrostatic analyzers) and the Solar Probe Cup (SPC). SPC is a Faraday cup, a metal device that can catch charged particles in a vacuum. Peeking over the heat shield to measure how electrons and ions are moving, the cup is exposed to the full light, heat and energy of the Sun. The cup is composed of a series of highly transparent grids — one of which uses variable high voltages to sort the particles — above several collector plates, which measure the particles' properties. The variable voltage grid also helps sort out background noise, such as cosmic rays and photoionized electrons, which could otherwise bias the measurements. The grids, located near the front of the instrument, can reach temperatures of {{convert|1650|C|F}}, glowing red while the instrument makes measurements. The instrument uses pieces of sapphire to electrically isolate different components within the cup. As it passes close to the Sun, SPC takes up to 146 measurements per second to accurately determine the velocity, density and temperature of the Sun's plasma. SPAN is composed of two instruments, SPAN-A and SPAN-B, which have wide fields of view to allow them to see the parts of space not observed by SPC. Particles encountering the detectors enter a maze that sends the particles through a series of deflectors and voltages to sort the particles based on their mass and charge. While SPAN-A has two components to measure both electrons and ions, SPAN-B looks only at electrons. The Principal Investigator is Justin Kasper at the University of Michigan and the Smithsonian Astrophysical Observatory.

An additional theoretical investigation named Heliospheric origins with Solar Probe Plus (HeliOSPP) starting from 2010 and ending in 2024 has the role of providing theoretical input and independent assessment of scientific performance to the Science Working Group (SWG) and the SPP Project to maximize the scientific return from the mission. The Principal Investigator is Marco Velli at the University of California, Los Angeles and the Jet Propulsion Laboratory; he also serves as the Observatory Scientist for the mission.{{cite journal| last1=Fox|first1=N.J.| last2=Velli|first2=M.C.| last3=Bale|first3=S.D.| last4=Decker|first4=R.|last5=Driesman|first5=A.|last6=Howard|first6=R.A. |last7=Kasper|first7=J.C.| last8=Kinnison|first8=J.| last9=Kusterer|first9=M.| first10=D.|last10=Lario| first11=M.K.|last11=Lockwood| first12=D.J.|last12=McComas| first13=N.E.| last13=Raouafi| first14=A.| last14=Szabo | date = November 11, 2015|title=The Solar Probe Plus Mission: Humanity's First Visit to Our Star|journal=Space Science Reviews| volume=204| issue=1–4| pages=7–48| doi=10.1007/s11214-015-0211-6| issn=0038-6308 | bibcode=2016SSRv..204....7F | doi-access=free}} 50px Text was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License].

File:Parker Solar Probe Launch (NHQ201808120013).jpg

File:Parker Solar Probe.jpg

The Parker Solar Probe was launched on 12 August 2018, at 07:31 UTC. The spacecraft operated nominally after launching. During its first week in space it deployed its high-gain antenna, magnetometer boom, and electric field antennas.{{cite web|url=https://spaceflightnow.com/2018/08/19/first-mission-milestones-accomplished-on-nasas-newly-launched-parker-solar-probe/|title=First milestones accomplished on NASA's newly-launched Parker Solar Probe – Spaceflight Now|website=spaceflightnow.com|access-date=August 22, 2018|archive-date=August 22, 2018|archive-url=https://web.archive.org/web/20180822181409/https://spaceflightnow.com/2018/08/19/first-mission-milestones-accomplished-on-nasas-newly-launched-parker-solar-probe/|url-status=live}} The spacecraft performed its first scheduled trajectory correction on 20 August 2018, while it was 8.8 million kilometers (5.5 million mi) from Earth, and travelling at {{convert|63569|km/h|sp=us}}[http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=96 After Near-Perfect Trajectory Maneuver, Parker Solar Probe On Course To Touch The Sun] {{Webarchive|url=https://web.archive.org/web/20180826005039/http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=96 |date=August 26, 2018 }}. NASA. August 21, 2018 {{PD-notice}}

Instrument activation and testing began in early September 2018. On 9 September 2018, the two WISPR telescopic cameras performed a successful first-light test, transmitting wide-angle images of the background sky towards the Galactic Center.{{cite web|url=https://blogs.nasa.gov/parkersolarprobe/2018/09/19/illuminating-first-light-data-from-parker-solar-probe/|website=blogs.nasa.gov/parkersolarprobe|title=Illuminating First Light Data from Parker Solar Probe|date=September 19, 2018|access-date=September 22, 2018|archive-date=September 22, 2018|archive-url=https://web.archive.org/web/20180922072822/https://blogs.nasa.gov/parkersolarprobe/2018/09/19/illuminating-first-light-data-from-parker-solar-probe/|url-status=live}} {{PD-notice}}

The probe successfully performed the first of the seven planned Venus flybys on 3 October 2018, where it came within about {{convert|2400|km|sp=us}} of Venus in order to reduce the probe's speed and orbit closer to the Sun.

File:Parker Solar Probe Flyby of Venus.svg

Within each orbit of the Parker Solar Probe around the Sun, the portion within 0.25 AU is the Science Phase, in which the probe is actively and autonomously making observations. Communication with the probe is largely cut off in that phase.{{cite conference|url=https://www.researchgate.net/publication/301998540|title=Solar Probe Plus Mission Design Overview and Mission Profile|last1=Guo|first1=Yanping|last2=Ozimek|first2=Martin|last3=Mcadams|first3=James|last4=Shyong|first4=Wen-Jong|date=May 2014|conference=International Symposium on Space Flight Dynamics, at Laurel, MD|website=ResearchGate|access-date=November 6, 2018|archive-date=May 2, 2022|archive-url=https://web.archive.org/web/20220502174648/https://www.researchgate.net/publication/301998540_SOLAR_PROBE_PLUS_MISSION_DESIGN_OVERVIEW_AND_MISSION_PROFILE|url-status=live}}{{rp|4}} Science phases run for a few days both before and after each perihelion. They lasted 11.6 days for the earliest perihelion, and will drop to 9.6 days for the final, closest perihelion.{{rp|8}}

Much of the rest of each orbit is devoted to transmitting data from the science phase. But during this part of each orbit, there are still periods when communication is not possible. First, the requirement that the heat shield of the probe be pointed towards the Sun sometimes puts the heat shield between the antenna and Earth. Second, even when the probe is not particularly near the Sun, when the angle between the probe and the Sun, as seen from Earth, is too small, the Sun's radiation can overwhelm the communication link.{{rp|11–14}}

After the first Venus flyby, the probe was in an elliptical orbit with a period of 150 days (two-thirds the period of Venus), making three orbits while Venus makes two. After the second flyby, the period shortened to 130 days. After less than two orbits, only 198 days later, it encountered Venus a third time at a point earlier in the orbit of Venus. This encounter shortened its period to half of that of Venus, or about 112.5 days. After two orbits it met Venus a fourth time at about the same place, shortening its period to about 102 days.

After 237 days, it met Venus for the fifth time and its period was shortened to about 96 days, three-sevenths that of Venus. It then made seven orbits while Venus made three. The sixth encounter, almost two years after the fifth, shortened its period down to 92 days, two-fifths that of Venus. After five more orbits (two orbits of Venus), it met Venus for the seventh and last time, decreasing its period to 88 or 89 days and allowing it to approach closer to the Sun.See data and figure at {{cite web|url=http://parkersolarprobe.jhuapl.edu/The-Mission/index.php#Journey-to-the-Sun|title=Solar Probe Plus: The Mission|date=2017|publisher=Johns Hopkins University Applied Physics Laboratory|access-date=June 17, 2017|archive-date=August 22, 2017|archive-url=https://web.archive.org/web/20170822222954/http://parkersolarprobe.jhuapl.edu/The-Mission/index.php#Journey-to-the-Sun|url-status=live}} {{PD-notice}}

{{wide image|Velocity of Parker Solar Probe wide.svg|900px|The speed of the probe and distance from the Sun, from launch until 2026|center|alt=}}

{{Notelist}}

File:Switchbacks on the Sun.gif

File:Parker Solar Probe touches the Sun.webm. Inside the boundary at the corona's edge, its Alfvén critical surface, plasma connects to the Sun by waves traveling back and forth to the surface.]]

On November 6, 2018, Parker Solar Probe observed its first magnetic switchbacks – sudden reversals in the direction of the magnetic field carried by the solar wind.{{cite web |last1=Hatfield |first1=Miles |title=New Insight Into Parker Solar Probe's Early Observations |url=https://www.nasa.gov/feature/goddard/2020/new-insight-into-parker-solar-probes-early-observations |website=NASA |date=29 April 2020}}{{PD-notice}} They were first observed by the NASA-ESA mission Ulysses, the first spacecraft to fly over the Sun's poles.{{cite web |last1=Hatfield |first1=Miles |title=Switchbacks Science: Explaining Parker Solar Probe's Magnetic Puzzle |url=https://www.nasa.gov/feature/goddard/2021/switchbacks-science-explaining-parker-solar-probe-s-magnetic-puzzle |website=NASA |access-date=31 July 2022 |date=8 March 2021}}{{PD-notice}}{{cite journal |last1=Fisk |first1=L. A. |last2=Kasper |first2=J. C. |title=Global Circulation of the Open Magnetic Flux of the Sun |journal=The Astrophysical Journal Letters |date=1 May 2020 |volume=894 |issue=1 |pages=L4 |doi=10.3847/2041-8213/ab8acd|bibcode=2020ApJ...894L...4F |doi-access=free }}50px Material was copied from this source, which is available under a [https://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0] The switchbacks generate heat that warms solar corona.{{cite web |last1=Zurbuchen |first1=Thomas |title=How a NASA Probe Solved a Scorching Solar Mystery |date=April 29, 2024 |url=https://www.quantamagazine.org/how-a-nasa-probe-solved-a-scorching-solar-mystery-20240429/ |publisher=Quanta Magazine |access-date=11 May 2024}}

On 4 December 2019, the first four research papers were published describing findings during the spacecraft's first two dives near the Sun.{{cite journal|last=Verscharen|first=Daniel|date=December 4, 2019 |title=A step closer to the Sun's secrets|journal=Nature|volume=576|issue=7786|pages=219–220|doi=10.1038/d41586-019-03665-3|pmid=31822830|bibcode=2019Natur.576..219V|doi-access=free}}{{cite news|url=https://www.nytimes.com/2019/12/04/science/nasa-parker-solar-probe-pictures.html|title=NASA's Parker Solar Probe Is Unlocking the Sun's Mysteries|last=Chang|first=Kenneth|date=December 4, 2019|work=The New York Times|access-date=January 16, 2024|issn=0362-4331|archive-date=December 5, 2019|archive-url=https://web.archive.org/web/20191205001130/https://www.nytimes.com/2019/12/04/science/nasa-parker-solar-probe-pictures.html|url-status=live}}{{Cite journal|last1=McComas|first1=D. J.|last2=Christian|first2=E. R.|last3=Cohen|first3=C. M. S.|last4=Cummings|first4=A. C. |last5=Davis|first5=A. J.|last6=Desai|first6=M. I.|last7=Giacalone|first7=J.|last8=Hill|first8=M. E.|last9=Joyce|first9=C. J.|last10=Krimigis|first10=S. M.|last11=Labrador|first11=A. W.|date=December 4, 2019 |title=Probing the energetic particle environment near the Sun|journal=Nature|volume=576|issue=7786|pages=223–227|doi=10.1038/s41586-019-1811-1|pmid=31802005|issn=1476-4687|pmc=6908744|bibcode=2019Natur.576..223M}}{{cite journal|last1=Howard|first1=R. A.|last2=Vourlidas|first2=A.|last3=Bothmer|first3=V.|last4=Colaninno|first4=R. C.|last5=DeForest|first5=C. E.|last6=Gallagher|first6=B.|last7=Hall|first7=J. R.|last8=Hess|first8=P.|last9=Higginson|first9=A. K.|last10=Korendyke|first10=C. M.|last11=Kouloumvakos|first11=A.|date=December 4, 2019|title=Near-Sun observations of an F-corona decrease and K-corona fine structure|journal=Nature|volume=576|issue=7786|pages=232–236|doi=10.1038/s41586-019-1807-x|pmid=31802002|bibcode=2019Natur.576..232H|hdl=2268/242497|s2cid=208620616|issn=1476-4687|url=https://orbi.uliege.be/handle/2268/242497|access-date=August 31, 2020|archive-date=June 25, 2020|archive-url=https://web.archive.org/web/20200625174408/https://orbi.uliege.be/handle/2268/242497|url-status=live}} They reported the direction and strength of the Sun's magnetic field, and described the unusually frequent and short-lived changes in the direction of the Sun's magnetic field. These measurements confirm the hypothesis that Alfvén waves are the leading candidates for understanding the mechanisms that underlie the coronal heating problem.{{cite journal|last1=Bale|first1=S. D.|last2=Badman|first2=S. T. |last3=Bonnell|first3=J. W.|last4=Bowen|first4=T. A.|last5=Burgess|first5=D.|last6=Case|first6=A. W.|author-link6=Anthony W. Case|last7=Cattell|first7=C. A.|author-link7=Cynthia Cattell|last8=Chandran|first8=B. D. G.|last9=Chaston|first9=C. C.|last10=Chen|first10=C. H. K.|last11=Drake|first11=J. F.|date=December 4, 2019|title=Highly structured slow solar wind emerging from an equatorial coronal hole|journal=Nature|volume=576|issue=7786|pages=237–242|doi=10.1038/s41586-019-1818-7|pmid=31802007|bibcode=2019Natur.576..237B|issn=1476-4687|hdl=11603/17219|s2cid=208623434|url=https://qmro.qmul.ac.uk/xmlui/handle/123456789/62038 |hdl-access=free}} The probe observed approximately a thousand "rogue" magnetic waves in the solar atmosphere that instantly increase solar wind speeds by as much as {{convert|300000|mph|kph}} and in some cases completely reverse the local magnetic field.{{cite journal|last=Witze|first=Alexandra |date=December 4, 2019|title=Sun-bombing spacecraft uncovers secrets of the solar wind|journal=Nature|volume=576|issue=7785|pages=15–16|doi=10.1038/d41586-019-03684-0|pmid=31802020|bibcode=2019Natur.576...15W |doi-access=free}}{{cite news|last=Drake|first=Nadia|author-link=Nadia Drake|url=https://www.nationalgeographic.com/science/2019/12/sun-keeps-getting-stranger-parker-solar-probe-shows/|title=The sun keeps getting stranger, dive-bombing solar probe shows|date=December 4, 2019|work=National Geographic|access-date=December 6, 2019|archive-date=December 6, 2019|archive-url=https://web.archive.org/web/20191206002311/https://www.nationalgeographic.com/science/2019/12/sun-keeps-getting-stranger-parker-solar-probe-shows/|url-status=dead}}

They also reported that, using the "beam of electrons that stream along the magnetic field", they were able to observe that "the reversals in the Sun's magnetic field are often associated with localized enhancements in the radial component of the plasma velocity (the velocity in the direction away from the Sun's center)". The researchers found a "surprisingly large azimuthal component of the plasma velocity (the velocity perpendicular to the radial direction). This component results from the force with which the Sun's rotation slingshots plasma out of the corona when the plasma is released from the coronal magnetic field".{{cite journal |last1=Kasper |first1=J. C. |last2=Bale |first2=S. D.|last3=Belcher|first3=J. W.|last4=Berthomier|first4=M.|last5=Case|first5=A. W.|author-link5=Anthony W. Case|last6=Chandran|first6=B. D. G.|last7=Curtis|first7=D. W.|last8=Gallagher|first8=D.|last9=Gary|first9=S. P. |last10=Golub |first10=L. |last11=Halekas |first11=J. S. |date=December 4, 2019|title=Alfvénic velocity spikes and rotational flows in the near-Sun solar wind|journal=Nature|volume=576|issue=7786|pages=228–231 |doi=10.1038/s41586-019-1813-z |pmid=31802006 |bibcode=2019Natur.576..228K |issn=1476-4687 |hdl=10150/636481 |hdl-access=free |s2cid=208625853}}

PSP discovered evidence of a cosmic dust-free zone of 3.5 million miles (5.6 million kilometers) radius from the Sun, due to vaporisation of cosmic dust particles by the Sun's radiation.{{cite web|url=https://www.sciencealert.com/the-sun-s-magnetic-field-appears-to-unexpectedly-flip-and-scientists-don-t-know-what-s-going-on|title=Scientists 'Blown Away' by Unexpected Results From NASA's Sun-Kissing Solar Probe|last=Tangermann|first=Victor|date=December 4, 2019 |publisher=ScienceAlert|agency=Futurism|access-date=December 16, 2019|archive-date=December 16, 2019|archive-url=https://web.archive.org/web/20191216012915/https://www.sciencealert.com/the-sun-s-magnetic-field-appears-to-unexpectedly-flip-and-scientists-don-t-know-what-s-going-on|url-status=live}}

On April 28, 2021, during its eighth flyby of the Sun, Parker Solar Probe encountered the specific magnetic and particle conditions at 18.8 solar radii that indicated that it penetrated the Alfvén surface;{{cite web |last1=Hatfield |first1=Miles |title=NASA Enters the Solar Atmosphere for the First Time |url=https://www.nasa.gov/feature/goddard/2021/nasa-enters-the-solar-atmosphere-for-the-first-time-bringing-new-discoveries |website=NASA |date=13 December 2021}}{{PD-notice}}{{cite web |title=GMS: Animation: NASA's Parker Solar Probe Enters Solar Atmosphere |url=https://svs.gsfc.nasa.gov/14036 |website=svs.gsfc.nasa.gov |access-date=30 July 2022 |language=en |date=14 December 2021}} the probe measured the solar wind plasma environment with its FIELDS and SWEAP instruments.{{cite web |title=SVS: Parker Solar Probe: Crossing the Alfven Surface |url=https://svs.gsfc.nasa.gov/4958 |website=svs.gsfc.nasa.gov |access-date=30 July 2022 |language=en |date=14 December 2021}}{{PD-notice}} This event was described by NASA as "touching the Sun".

On 25 September 2022, the first discovery of a comet was made in images from the Parker Solar Probe. The comet is named PSP-001. It was found by Peter Berrett, who participates in the NASA funded Sungrazer project.{{cite web |title=Welcome to Sungrazer |url=https://sungrazer.nrl.navy.mil |website=sungrazer.nrl.navy.mil |access-date=18 July 2023 |language=en }}{{PD-notice}} PSP-001 was discovered in images from 29 May 2022, part of the spacecraft's 12th approach to the Sun.

Since this discovery, a further 19 sungrazing comets have been discovered in the images taken by the Parker Solar Probe, including three non-group comets.

In 2024, it was reported that the probe detected a Kelvin-Helmholtz instability (KHI) during an observed coronal mass ejection. It is the first spacecraft that detected this long theorized event.{{Cite journal|title=First Direct Imaging of a Kelvin-Helmholtz Instability by PSP/WISPR|author1=Paouris, Evangelos|author2=Stenborg, Guillermo|author3=Linton, Mark G.|author4=Vourlidas, Angelos|author5=Howard, Russell A.|author6=Raouafi, Nour E.|year=2024|journal=The Astrophysical Journal|volume=964|issue=2|pages=139|doi=10.3847/1538-4357/ad2208|doi-access=free |bibcode=2024ApJ...964..139P }}

The PSP and ESA-NASA Solar Orbiter (SolO) missions cooperated to trace solar wind and transients from their sources on the Sun to the inner interplanetary space.{{cite journal |last1=Biondo |first1=Ruggero |last2=Bemporad |first2=Alessandro |last3=Pagano |first3=Paolo |last4=Telloni |first4=Daniele |last5=Reale |first5=Fabio |last6=Romoli |first6=Marco |last7=Andretta |first7=Vincenzo |last8=Antonucci |first8=Ester |last9=Da Deppo |first9=Vania |last10=De Leo |first10=Yara |last11=Fineschi |first11=Silvano |last12=Heinzel |first12=Petr |last13=Moses |first13=Daniel |last14=Naletto |first14=Giampiero |last15=Nicolini |first15=Gianalfredo |last16=Spadaro |first16=Daniele |last17=Stangalini |first17=Marco |last18=Teriaca |first18=Luca |last19=Landini |first19=Federico |last20=Sasso |first20=Clementina |last21=Susino |first21=Roberto |last22=Jerse |first22=Giovanna |last23=Uslenghi |first23=Michela |last24=Pancrazzi |first24=Maurizio |title=Connecting Solar Orbiter remote-sensing observations and Parker Solar Probe in situ measurements with a numerical MHD reconstruction of the Parker spiral |journal=Astronomy & Astrophysics |date=December 2022 |volume=668 |pages=A144 |doi=10.1051/0004-6361/202244535 |display-authors=1|arxiv=2211.12994 |bibcode=2022A&A...668A.144B }} {{Creative Commons text attribution notice|cc=by4|from this source=yes}}

In 2022, PSP and SolO planners collaborated to study why the Sun's atmosphere is "150 times hotter" than its surface. SolO observed the Sun from 140 million kilometers, while PSP simultaneously observed the Sun's corona during flyby at a distance of nearly 9 million kilometers.{{cite magazine |last1=Skibba |first1=Ramin |title=A Pair of Sun Probes Just Got Closer to Solving a Solar Enigma |url=https://www.wired.com/story/a-pair-of-sun-probes-just-got-closer-to-solving-a-solar-enigma/ |magazine=Wired |access-date=30 March 2024 |archive-url=https://archive.today/20230920125049/https://www.wired.com/story/a-pair-of-sun-probes-just-got-closer-to-solving-a-solar-enigma/ |archive-date=20 September 2023}}{{cite journal |last1=Telloni |first1=Daniele |last2=Romoli |first2=Marco |last3=Velli |first3=Marco |last4=Zank |first4=Gary P. |last5=Adhikari |first5=Laxman |last6=Downs |first6=Cooper |last7=Burtovoi |first7=Aleksandr |last8=Susino |first8=Roberto |last9=Spadaro |first9=Daniele |last10=Zhao |first10=Lingling |last11=Liberatore |first11=Alessandro |last12=Shi |first12=Chen |last13=De Leo |first13=Yara |last14=Abbo |first14=Lucia |last15=Frassati |first15=Federica |last16=Jerse |first16=Giovanna |last17=Landini |first17=Federico |last18=Nicolini |first18=Gianalfredo |last19=Pancrazzi |first19=Maurizio |last20=Russano |first20=Giuliana |last21=Sasso |first21=Clementina |last22=Andretta |first22=Vincenzo |last23=Da Deppo |first23=Vania |last24=Fineschi |first24=Silvano |last25=Grimani |first25=Catia |last26=Heinzel |first26=Petr |last27=Moses |first27=John D. |last28=Naletto |first28=Giampiero |last29=Stangalini |first29=Marco |last30=Teriaca |first30=Luca |last31=Uslenghi |first31=Michela |last32=Berlicki |first32=Arkadiusz |last33=Bruno |first33=Roberto |last34=Capobianco |first34=Gerardo |last35=Capuano |first35=Giuseppe E. |last36=Casini |first36=Chiara |last37=Casti |first37=Marta |last38=Chioetto |first38=Paolo |last39=Corso |first39=Alain J. |last40=D’Amicis |first40=Raffaella |last41=Fabi |first41=Michele |last42=Frassetto |first42=Fabio |last43=Giarrusso |first43=Marina |last44=Giordano |first44=Silvio |last45=Guglielmino |first45=Salvo L. |last46=Magli |first46=Enrico |last47=Massone |first47=Giuseppe |last48=Messerotti |first48=Mauro |last49=Nisticò |first49=Giuseppe |last50=Pelizzo |first50=Maria G. |last51=Reale |first51=Fabio |last52=Romano |first52=Paolo |last53=Schühle |first53=Udo |last54=Solanki |first54=Sami K. |last55=Straus |first55=Thomas |last56=Ventura |first56=Rita |last57=Volpicelli |first57=Cosimo A. |last58=Zangrilli |first58=Luca |last59=Zimbardo |first59=Gaetano |last60=Zuppella |first60=Paola |last61=Bale |first61=Stuart D. |last62=Kasper |first62=Justin C. |title=Coronal Heating Rate in the Slow Solar Wind |journal=The Astrophysical Journal Letters |date=1 September 2023 |volume=955 |issue=1 |pages=L4 |doi=10.3847/2041-8213/ace112 |doi-access=free |arxiv=2306.10819 |bibcode=2023ApJ...955L...4T |display-authors=1}}

In March 2024, both space probes were at their closest approaches to the Sun, PSP at 7.3 million km, and SolO at 45 million km. SolO observed the Sun, while PSP sampled the plasma of the solar wind, allowing scientists to compare data from both probes.{{cite web |title=ESA and NASA team up to study solar wind |url=https://www.esa.int/Science_Exploration/Space_Science/Solar_Orbiter/ESA_and_NASA_team_up_to_study_solar_wind |website=www.esa.int |access-date=30 March 2024 |language=en}}

File:WISPR first light image.png|WISPR first light image. The right portion of the image is from WISPR's inner telescope, which is a 40-degree field of view and begins 58.5 degrees from the Sun's center. The left portion is from the outer telescope, which is a 58-degree field of view and ends about 160 degrees from the Sun.{{Cite web |url=http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=101 |title=Illuminating First Light Data from Parker Solar Probe |publisher=Johns Hopkins University Applied Physics Laboratory |first1=Sarah |last1=Frazier |first2=Justyna |last2=Surowiec |date=19 September 2018 |access-date=22 September 2018 |archive-date=December 30, 2021 |archive-url=https://web.archive.org/web/20211230155521/http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=101 |url-status=live }}

File:Parker-view-of-earth.jpg|The view from the probe's WISPR instrument on Sept. 25, 2018, shows Earth, the bright sphere near the middle of the right-hand panel. The elongated mark toward the bottom of the panel is a lens reflection from the WISPR instrument{{cite web |last1=Garner |first1=Rob |title=Parker Solar Probe Looks Back at Home |url=https://www.nasa.gov/feature/goddard/2018/parker-solar-probe-looks-back-at-home |website=NASA |access-date=29 April 2022 |date=22 October 2018 |archive-date=April 29, 2022 |archive-url=https://web.archive.org/web/20220429112442/https://www.nasa.gov/feature/goddard/2018/parker-solar-probe-looks-back-at-home/ |url-status=live }}

File:Parker Solar Probe coronal stream wispr-big 1-st flyby.jpg|Photo from the WISPR shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. The fine structure of the streamer is very clear, with at least two rays visible. Parker Solar Probe was about 16.9 million miles (21.2 million km) from the Sun's surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction.{{Cite web|url=http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=115|title=Preparing for Discovery With NASA's Parker Solar Probe|publisher=Johns Hopkins University Applied Physics Laboratory|website=Parker Solar Probe|language=en|access-date=2018-12-23|archive-date=February 14, 2022|archive-url=https://web.archive.org/web/20220214234620/http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=115|url-status=live}}

File:Wispr merged six planets.jpg|When Parker Solar Probe was making its closest approach to the Sun on June 7, 2020, WISPR captured the planets Mercury, Venus, Earth, Mars, Jupiter and Saturn in its field of view{{cite web |last1=Buckley |first1=Mike |title=Parker Solar Probe Captures a Planetary Portrait |url=http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=158 |website=Parker Solar Probe |publisher=Johns Hopkins APL |access-date=29 April 2022 |language=en |archive-date=April 29, 2022 |archive-url=https://web.archive.org/web/20220429112813/http://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=158 |url-status=live }}

File:Venus-ParkerSolarProbe-July2020.jpg|Photo taken by the probe during its second Venus flyby, July 2020

File:Parker Solar Probe flew by Venus on its fourth flyby.gif|As Parker Solar Probe flew by Venus on its fourth flyby, its WISPR instrument captured these images, showing the nightside surface of the planet{{cite web |last1=Hatfield |first1=Miles |title=Parker Solar Probe Captures Visible Light Images of Venus' Surface |url=https://www.nasa.gov/feature/goddard/2022/sun/parker-solar-probe-captures-its-first-images-of-venus-surface-in-visible-light-confirmed |website=NASA |access-date=29 April 2022 |date=9 February 2022 |archive-date=April 14, 2022 |archive-url=https://web.archive.org/web/20220414155959/https://www.nasa.gov/feature/goddard/2022/sun/parker-solar-probe-captures-its-first-images-of-venus-surface-in-visible-light-confirmed/ |url-status=live }}{{cite journal | journal=Geophysical Research Letters | last1=Wood | first1=B. E. | last2=Hess | first2=P. | last3=Lustig-Yaeger | first3=J. | last4=Gallagher | first4=B. | last5=Korwan | first5=D. | last6=Rich | first6=N. | last7=Stenborg | first7=G. | last8=Thernisien | first8=A. | last9=Qadri | first9=S. N. | last10=Santiago | first10=F. | last11=Peralta | first11=J. | last12=Arney | first12=G. N. | last13=Izenberg | first13=N. R. | last14=Vourlidas | first14=A. | last15=Linton | first15=M. G. | last16=Howard | first16=R. A. | last17= Raouafi | first17=N. E. | doi=10.1029/2021GL096302 | date=February 9, 2022 | title=Parker Solar Probe Imaging of the Night Side of Venus | volume=49 | issue=3| pages=e2021GL096302 | pmid=35864851 | pmc=9286398 | bibcode=2022GeoRL..4996302W }}

File:Parker Solar Probe Encounters Streamers on the Way to the Sun.webm|As the probe passed through the Sun's corona in early 2021, it flew by structures called coronal streamers (timelapse encompassing 4 days)

• {{annotated link|Living With a Star}}
• List of heliophysics missions
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• {{annotated link|Spacecraft thermal control}}

{{Reflist|group=note}}

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{{Commons category}}

• [http://parkersolarprobe.jhuapl.edu/ Parker Probe Plus] at Johns Hopkins University Applied Physics Laboratory (JHUAPL)
• [https://web.archive.org/web/20110719221441/http://solarprobe.jhuapl.edu/mission/docs/SolarProbeME.pdf Solar Probe Plus] (Mission Engineering Report; JHUAPL)
• [https://web.archive.org/web/20160828040133/http://science.nasa.gov/about-us/smd-programs/heliophysics-research/ Heliophysics Research] (NASA)
• [http://ehpd.gsfc.nasa.gov/ Explorers and Heliophysics Projects Division] (EHPD; NASA)
• [https://www.nasa.gov/content/goddard/parker-solar-probe Parker Solar Probe] (data and news; NASA)
• [https://www.nytimes.com/video/science/100000006012333/nasa-parker-solar-probe.html Parker Solar Probe] (Video/3:45; NYT; August 12, 2018)
• [https://www.youtube.com/watch?v=BUClxcUbuNM Parker Solar Probe] (Video—360°/3:27; NASA; September 6, 2018)
• [https://directory.eoportal.org/web/eoportal/satellite-missions/p/psp#mission-status eoPortal: Mission Status]
• [https://wispr.nrl.navy.mil/encounter-summaries PSP/WISPR Encounter Summaries]

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