In the summer of 2018, we’re launching Parker Solar Probe, a spacecraft that will get closer to the Sun than any other in human history.
Parker Solar Probe will fly directly through the Sun’s atmosphere, called the corona. Getting better measurements of this region is key to understanding our Sun. For instance, the Sun releases a constant outflow of solar material, called the solar wind. We think the corona is where this solar wind is accelerated out into the solar system, and Parker Solar Probe’s measurements should help us pinpoint how that happens.
The solar wind, along with other changing conditions on the Sun and in space, can affect Earth and are collectively known as space weather. Space weather can trigger auroras, create problems with satellites, cause power outages (in extreme cases), and disrupt our communications signals. That’s because space weather interacts with Earth’s upper atmosphere, where signals like radio and GPS travel from place to place.
Parker Solar Probe is named after pioneering physicist Gene Parker. In the 1950s, Parker proposed a number of concepts about how stars — including our Sun — give off energy. He called this cascade of energy the solar wind. Parker also theorized an explanation for the superheated solar atmosphere, the corona, which is hotter than the surface of the Sun itself.
Getting the answers to our questions about the solar wind and the Sun’s energetic particles is only possible by sending a probe right into the furnace of the Sun’s corona, where the spacecraft can reach 2,500 degrees Fahrenheit. Parker Solar Probe and its four suites of instruments – studying magnetic and electric fields, energetic particles, and the solar wind – will be protected from the Sun’s enormous heat by a 4.5-inch-thick carbon-composite heat shield.
Over the course of its seven-year mission, Parker Solar Probe will make two dozen close approaches to the Sun, continuously breaking its own records and sending back unprecedented science data.
Getting close to the Sun is harder than you might think, since the inertia of a spacecraft launched from Earth will naturally carry it in repeated orbits on roughly the same path. To nudge the orbit closer to the Sun on successive trips, Parker Solar Probe will use Venus’ gravity.
This is a technique called a gravity assist, and it’s been used by Voyager, Cassini, and OSIRIS-REx, among other missions. Though most missions use gravity assists to speed up, Parker Solar Probe is using Venus’ gravity to slow down. This will let the spacecraft fall deeper into the Sun’s gravity and get closer to our star than any other spacecraft in human history.
You can get a behind-the-scenes at Parker Solar Probe under construction in a clean room at facebook.com/NASASunScience today (Sept. 25) at 1:45 PM EDT.
Media Invited to View NASA Spacecraft That Will Touch Our Sun
NASA’s Parker Solar Probe will be humanity’s first-ever mission to explore the Sun’s outer atmosphere. Media are invited to see the spacecraft and learn about the mission from noon to 2 p.m. EDT Monday, Sept. 25, at Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, where the probe is being built.
The spacecraft will be in full flight configuration, complete with its revolutionary heat shield, and members of the engineering and science teams conducting this historical mission will be available for interviews.
Media who would like to attend must register with APL by sending an email with name, affiliation and cell phone number to firstname.lastname@example.org no later than 5 p.m. on Friday, Sept. 22. Instructions on attendance will be provided upon registration.
Due to facility limitations, the number of participants is limited, and the event is open only to U.S. citizens. The event will take place in a clean room. Attendees should allow additional time for cleaning of cameras and equipment by APL staff.
The spacecraft, about the size of a small car, will launch in mid-summer 2018. It will travel directly through the Sun's atmosphere about four million miles from our star's surface – facing heat and radiation unlike any spacecraft in history – and make critical observations to answer decades-old questions about how stars work. Mission data ultimately will improve forecasts of major space weather events that affect life on Earth, as well as satellites and astronauts in space.
Parker Solar Probe: Humanity’s First Visit to a Star
NASA's historic Parker Solar Probe mission will revolutionize our understanding of the sun, where changing conditions can propagate out into the solar system, affecting Earth and other worlds. Parker Solar Probe will travel through the sun’s atmosphere, closer to the surface than any spacecraft before it, facing brutal heat and radiation conditions — and ultimately providing humanity with the closest-ever observations of a star.
Journey to the Sun
- Launch Window: July 31 – Aug. 19, 2018
- Launch Site: NASA's Kennedy Space Center, Florida
- Launch Vehicle: Delta IV-Heavy with Upper Stage
In order to unlock the mysteries of the sun's atmosphere, Parker Solar Probe will use Venus’ gravity during seven flybys over nearly seven years to gradually bring its orbit closer to the sun. The spacecraft will fly through the sun’s atmosphere as close as 3.9 million miles to our star’s surface, well within the orbit of Mercury and more than seven times closer than any spacecraft has come before. (Earth’s average distance to the sun is 93 million miles.)
Flying into the outermost part of the sun's atmosphere, known as the corona, for the first time, Parker Solar Probe will employ a combination of in situ measurements and imaging to revolutionize our understanding of the corona and expand our knowledge of the origin and evolution of the solar wind. It will also make critical contributions to our ability to forecast changes in Earth's space environment that affect life and technology on Earth.
At closest approach, Parker Solar Probe hurtles around the sun at approximately 430,000 mph (700,000 kph). That's fast enough to get from Philadelphia to Washington, D.C., in one second.
At closest approach to the sun, the front of Parker Solar Probe's solar shield faces temperatures approaching 2,500 F (1,377 C). The spacecraft's payload will be near room temperature.
On the final three orbits, Parker Solar Probe flies to within 3.7 million miles of the sun's surface – more than seven times closer than the current record-holder for a close solar pass, the Helios 2 spacecraft, which came within 27 million miles in 1976 and more than 10 times closer than Mercury, which is about 42 million miles from the sun.
Parker Solar Probe will perform its scientific investigations in a hazardous region of intense heat and solar radiation. The spacecraft will fly close enough to the sun to watch the solar wind speed up from subsonic to supersonic, and it will fly though the birthplace of the highest-energy solar particles.
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 F (1,377 C).
The Science of the Sun
The primary science goals for the mission are to trace how energy and heat move through the solar corona and to explore what accelerates the solar wind as well as solar energetic particles. Scientists have sought these answers for more than 60 years, but the investigation requires sending a probe right through the 2,500 degrees Fahrenheit heat of the corona. Today, this is finally possible with cutting-edge thermal engineering advances that can protect the mission on its dangerous journey. Parker Solar Probe will carry four instrument suites designed to study magnetic fields, plasma and energetic particles, and image the solar wind.
Teaming for Success
Parker Solar Probe is part of NASA’s Living With a Star program to explore aspects of the sun-Earth system that directly affect life and society. The Living With a Star flight program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, manages the mission for NASA. APL is designing and building the spacecraft and will also operate it.
Why do we study the sun and the solar wind?
- The sun is the only star we can study up close. By studying this star we live with, we learn more about stars throughout the universe.
- The sun is a source of light and heat for life on Earth. The more we know about it, the more we can understand how life on Earth developed.
- The sun also affects Earth in less familiar ways. It is the source of the solar wind; a flow of ionized gases from the sun that streams past Earth at speeds of more than 500 km per second (a million miles per hour).
- Disturbances in the solar wind shake Earth's magnetic field and pump energy into the radiation belts, part of a set of changes in near-Earth space known as space weather.
- Space weather can change the orbits of satellites, shorten their lifetimes, or interfere with onboard electronics. The more we learn about what causes space weather – and how to predict it – the more we can protect the satellites we depend on.
- The solar wind also fills up much of the solar system, dominating the space environment far past Earth. As we send spacecraft and astronauts further and further from home, we must understand this space environment just as early seafarers needed to understand the ocean.
Parker Solar Probe Comes to NASA Goddard for Testing
On Monday, Nov. 6, 2017, NASA's Parker Solar Probe spacecraft arrived at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for environmental tests. During the spacecraft’s stay at Goddard, engineers and technicians will simulate extreme temperatures and other physical stresses that the spacecraft will be subjected to during its historic mission to the Sun.
Before arriving at Goddard, Parker Solar Probe was at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, where it was designed and built.
NASA’s Parker Solar Probe is scheduled for launch on July 31, 2018, from Cape Canaveral Air Force Station, Florida. The spacecraft will explore the Sun’s outer atmosphere and make critical observations that will answer decades-old questions about the physics of stars. The resulting data will also help improve how we forecast major eruptions on the Sun and subsequent space weather events that can impact life on Earth, as well as satellites and astronauts in space.
Watch Purple Lasers Light Up NASA's Parker Solar Probe in Test
NASA's Parker Solar Probe — which will fly closer to the sun than any spacecraft in history — recently passed an important prelaunch test of its solar panels with flying colors. Well, one color, in particular: Researchers used purple lasers at NASA's Goddard Space Flight Center to examine the probe.
Coincidentally, the purple hue of the lasers recalls Pantone's 2018 Color of the Year, a regal hue dubbed Ultra Violet by the Pantone Color Institute. Aptly enough, the company's executive director, Leatrice Eiseman, said in a statement that the color "suggests the mysteries of the cosmos, the intrigue of what lies ahead and the discoveries beyond where we are now."
Credit: NASA/Johns Hopkins APL/Ed Whitman
Aimed at the spacecraft's solar array, the purple lasers helped researchers verify that the 44 strings of solar cells on each panel are still electrically connected, following vibration and acoustic testing conducted earlier this fall, according to a statement from NASA. The vigorous noise and shaking helped simulate launch conditions that the probe will undergo when it takes off from Cape Canaveral Air Force Station in Florida on July 31, 2018.
The spacecraft will study the ejections of material and light that create "solar weather," and help scientists better understand some of the mysteries of our nearest star, such as why its atmosphere is hotter than its surface.
Critically, the panels will provide the power for the probe's sojourn in space. The laser testing was completed the week of Nov. 27, led by engineers at the Johns Hopkins Applied Physics Lab in Maryland, which is constructing the spacecraft and will operate it during its mission.
These tests use lasers because their tight beams allow the illumination of a single string of solar cells at a time, according to the statement. The color of a laser beam is determined by the wavelength of light that composes it. The engineers happened to have purple lasers readily available, and the solar cells operate efficiently at that wavelength, according to the statement.
The test also employed infrared lasers, which are invisible to the human eye.