Parker Solar Probe

Parker Solar Probe

Model of the Parker Solar Probe
Names	Solar Probe (before 2002) Solar Probe Plus (2010–2017) Parker Solar Probe (since 2017)
Mission type	Heliophysics
Operator	NASA / Applied Physics Laboratory
COSPAR ID	2018-065A
SATCAT no.	43592
Website	parkersolarprobe.jhuapl.edu
Mission duration	7 years (planned) Elapsed: 8 years and 32 days
Spacecraft properties
Manufacturer	Applied Physics Laboratory
Launch mass	685 kg (1,510 lb)
Dry mass	555 kg (1,224 lb)
Payload mass	50 kg (110 lb)
Dimensions	1 × 3 × 2.3 m (3.3 × 9.8 × 7.5 ft)
Power	343 W (at closest approach)
Start of mission
Launch date	12 August 2018, 07:31 UTC
Rocket	Delta IV Heavy / Star 48BV
Launch site	Cape Canaveral, SLC‑37
Contractor	United Launch Alliance
Orbital parameters
Reference system	Heliocentric orbit
Semi-major axis	0.388 AU (58.0 million km; 36.1 million mi)
Perihelion altitude	0.046 AU (6.9 million km; 4.3 million mi; 9.86 R☉)
Aphelion altitude	0.73 AU (109 million km; 68 million mi)
Inclination	3.4°
Period	88 days
Transponders
Band	Ka-band, X-band
Instruments SWEAP Solar Wind Electrons Alphas and Protons Investigation SPC Solar Probe Cup SPAN Solar Probe Analyzers WISPR Wide-field Imager for Solar Probe FIELDS Electromagnetic Fields Investigation IS☉IS Integrated Science Investigation of the Sun Energetic Particle Instruments
Mission insignia Large Strategic Science Missions Heliophysics Division Living With a Star program

The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 to make observations of the Sun's outer corona.

It used repeated gravity assists from Venus to develop an eccentric orbit, approaching within 9.86 solar radii (6.9 million km or 4.3 million miles) from the center of the Sun. At its closest approach in 2024, its speed relative to the Sun was 690,000 km/h (430,000 mph) or 191 km/s (118.7 mi/s), which is 0.064% the speed of light. It is the fastest object ever built on Earth.

The project was announced in the fiscal 2009 budget year. Johns Hopkins University Applied Physics Laboratory designed and built the spacecraft, which was launched on August 12, 2018. It became the first NASA spacecraft named after a living person, honoring the physicist Eugene Newman Parker, professor emeritus at the University of Chicago.

On October 29, 2018, at about 18:04 UTC, the spacecraft became the closest ever artificial object to the Sun. The previous record, 42.73 million kilometers (26.55 million miles) from the Sun's surface, was set by the Helios 2 spacecraft in April 1976. At its perihelion on September 27, 2023, the PSP's closest approach was 7.26 million kilometers (4.51 million miles), reaching this distance again on March 29, 2024.

On December 24, 2024, at 11:53 UTC, PSP made its closest approach to the Sun, coming to a distance of 6.1 million km (3.8 million miles) from the surface. Its beacon signal was received on December 26, showing that it had survived the passage through the corona. Detailed telemetry was received January 1, 2025.

In 2025, the teams from NASA, Johns Hopkins, and partners were awarded the 2024 Collier Trophy for their achievements.