#solarprobe

This summer, our Parker Solar Probe will launch to travel closer to the Sun than any mission before it, right into the Sun’s outer atmosphere, the corona.

The environment in the corona is unimaginably hot: The spacecraft will travel through material with temperatures greater than 3 million degrees Fahrenheit. 

So…why won’t it melt? 

The Difference Between Heat and Temperature

Parker Solar Probe was designed from the ground up to keep its instruments safe and cool, but the nature of the corona itself also helps. The key lies in the difference between heat and temperature.

Temperature measures how fast particles are moving, while heat is the total amount of energy that they transfer. The corona is an incredibly thin and tenuous part of the Sun, and there are very few particles there to transfer energy – so while the particles are moving fast (high temperature), they don't actually transfer much energy to the spacecraft (low heat).

It's like the difference between putting your hand in a hot oven versus putting it in a pot of boiling water (don’t try this at home!). In the air of the oven, your hand doesn't get nearly as hot as it would in the much denser water of the boiling pot. 

So even though Parker Solar Probe travels through a region with temperatures of several million degrees, the surface of its heat shield will reach only about 2,500 F.

The Heat Shield

Of course, thousands of degrees Fahrenheit is still way too hot for scientific instruments. (For comparison, lava from volcano eruptions can be anywhere between 1,300 to 2,200 F.) 

To withstand that heat, Parker Solar Probe is outfitted with a cutting-edge heat shield, called the Thermal Protection System. This heat shield is made of a carbon composite foam sandwiched between two carbon plates. The Sun-facing side is covered with a specially-developed white ceramic coating, applied as a plasma spray, to reflect as much heat as possible.

The heat shield is so good at its job that even though the Sun-facing side of the shield will be at 2,500 F, the instruments in its shadow will remain at a balmy 85 F.

Parker Solar Probe Keeps its Cool

Several other designs on the spacecraft help Parker Solar Probe beat the heat. 

Parker Solar Probe is not only studying the Sun – it's also powered by it. But even though most of the surface area of its solar arrays can be retracted behind the heat shield, even that small exposed segment would quickly make them overheat while at the Sun.  

To keep things cool, Parker Solar Probe circulates a single gallon of water through its solar arrays. The water absorbs heat as it passes behind the arrays, then radiates that heat out into space as it flows into the spacecraft's radiator. 

It's also important for Parker Solar Probe to be able to think on its feet, since it takes about eight minutes for information to travel between Earth and the Sun. If we had to control the spacecraft from Earth, by the time we knew something went wrong, it would be too late to fix it. 

So Parker Solar Probe is smart: Along the edges of the heat shield's shadow are seven sensors. If any of these sensors detect sunlight, they alert the central computer and the spacecraft can correct its position to keep the sensors – and the rest of the instruments – safely protected behind the heat shield.

Over the course of its seven-year mission, Parker Solar Probe will make 24 orbits of our star. On each close approach to the Sun, it will sample the solar wind, study the Sun’s corona, and provide unprecedentedly close up observations from around our star – and armed with its slew of innovative technologies, we know it will keep its cool the whole time. 

Parker Solar Probe launches summer 2018 on its mission to study the Sun. Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Justin Kasper, University of Michigan associate professor of climate and space sciences, prepares a model of the Faraday cup for testing prior to this summer’s Parker Solar Probe Launch. Kasper is principal investigator for Parker’s SWEAP investigation - charged with measuring the solar wind. The cup is tested in a vacuum chamber and hit with light from four modified IMAX projectors and particles from an ion gun - all to ensure it will operate in the sun’s atmosphere.

Learn more here. 

You might think you know the Sun: It looks quiet and unchanging. But the Sun has secrets that scientists have been trying to figure out for decades.  

One of our new missions — Parker Solar Probe — is aiming to spill the Sun’s secrets and shed new light on our neighbor in the sky.

Even though it’s 93 million miles away, the Sun is our nearest and best laboratory for understanding the inner workings of stars everywhere. We’ve been spying on the Sun with a fleet of satellites for decades, but we’ve never gotten a close-up of our nearest star.

This summer, Parker Solar Probe is launching into an orbit that will take it far closer to the Sun than any instrument has ever gone. It will fly close enough to touch the Sun, sweeping through the outer atmosphere — the corona — 4 million miles above the surface.

This unique viewpoint will do a lot more than provide gossip on the Sun. Scientists will take measurements to help us understand the Sun’s secrets — including those that can affect Earth.

Parker Solar Probe is equipped with four suites of instruments that will take detailed measurements from within the Sun's corona, all protected by a special heat shield to keep them safe and cool in the Sun's ferocious heat.

The corona itself is home to one of the Sun’s biggest secrets: The corona's mysteriously high temperatures. The corona, a region of the Sun’s outer atmosphere, is hundreds of times hotter than the surface below. That's counterintuitive, like if you got warmer the farther you walked from a campfire, but scientists don’t yet know why that's the case.

Some think the excess heat is delivered by electromagnetic waves called Alfvén waves moving outwards from the Sun’s surface. Others think it might be due to nanoflares — bomb-like explosions that occur on the Sun’s surface, similar to the flares we can see with telescopes from Earth, but smaller and much more frequent. Either way, Parker Solar Probe's measurements direct from this region itself should help us pin down what's really going on.

We also want to find out what exactly accelerates the solar wind — the Sun's constant outpouring of material that rushes out at a million miles per hour and fills the Solar System far past the orbit of Pluto. The solar wind can cause space weather when it reaches Earth — triggering things like the aurora, satellite problems, and even, in rare cases, power outages.

We know where the solar wind comes from, and that it gains its speed somewhere in the corona, but the exact mechanism of that acceleration is a mystery. By sampling particles directly at the scene of the crime, scientists hope Parker Solar Probe can help crack this case.

Parker Solar Probe should also help us uncover the secrets of some of the fastest particles from the Sun. Solar energetic particles can reach speeds of more than 50% the speed of light, and they can interfere with satellites with little warning because of how fast they move. We don't know how they get so fast — but it's another mystery that should be solved with Parker Solar Probe on the case.  

Parker Solar Probe launches summer 2018 on a seven-year mission to touch the Sun. Keep up with the latest on the Sun at @NASASun on Twitter, and follow along with Parker Solar Probe's last steps to launch at nasa.gov/solarprobe.

What's next for NASA? A quick look at some of the big things coming up:

1. We will add to our existing robotic fleet at the Red Planet with the InSight Mars lander set to study the planet's interior.

This terrestrial planet explorer will address one of the most fundamental issues of planetary and solar system science - understanding the processes that shaped the rocky planets of the inner solar system (including Earth) more than four billion years ago.

2. The Mars 2020 rover will look for signs of past microbial life, gather samples for potential future return to Earth.

The Mars 2020 mission takes the next step by not only seeking signs of habitable conditions on the Red Planet in the ancient past, but also searching for signs of past microbial life itself. The Mars 2020 rover introduces a drill that can collect core samples of the most promising rocks and soils and set them aside in a "cache" on the surface of Mars.

3. The James Webb Space Telescope will be the premier observatory of the next decade, studying the history of our Universe in infrared.

Webb will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own solar system.

4. The Parker Solar Probe will "touch the Sun," traveling closer to the surface than any spacecraft before.

This spacecraft, about the size of a small car, will travel directly into the sun's atmosphere about 4 million miles from our star's surface. 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.

5. Our OSIRIS-REx spacecraft arrives at the near-Earth asteroid Bennu in August 2018, and will return a sample for study in 2023.

This mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth.

6. Launching in 2018, the Transiting Exoplanet Survey Satellite (TESS) will search for planets around 200,000 bright, nearby stars.

The Transiting Exoplanet Survey Satellite (TESS) is the next step in the search for planets outside of our solar system (exoplanets), including those that could support life. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits.

7. A mission to Jupiter's ocean-bearing moon Europa is being planned for launch in the 2020s.

The mission will place a spacecraft in orbit around Jupiter in order to perform a detailed investigation of Europa -- a world that shows strong evidence for an ocean of liquid water beneath its icy crust and which could host conditions favorable for life.

8. We will launch our first integrated test flight of the Space Launch System rocket and Orion spacecraft, known as Exploration Mission-1.

The Space Launch System rocket will launch with Orion atop it. During Exploration Mission-1, Orion will venture thousands of miles beyond the moon during an approximately three week mission.

9. We are looking at what a flexible deep space gateway near the Moon could be.

We’ve issued a draft announcement seeking U.S. industry-led studies for an advanced solar electric propulsion (SEP) vehicle capability. The studies will help define required capabilities and reduce risk for the 50 kilowatt-class SEP needed for the agency’s near-term exploration goals.

10. Want to know more? Read the full story.

Mark your calendars for summer 2018: That's when we're launching a spacecraft to touch the sun. 

In honor of our first-ever mission to the heart of the solar system, this week we’re delving into the life and times of this powerful yellow dwarf star.

1. Meet Parker 

Parker Solar Probe, our first mission to go to the sun, is named after Eugene Parker, an American astrophysicist who first theorized that the sun constantly sends out a flow of particles and energy called the solar wind. This historic mission will explore one of the last regions of the solar system to be visited by a spacecraft and help scientists unlock answers to questions they've been pondering for more than five decades.

2. Extra SPF, Please 

Parker Solar Probe will swoop within 4 million miles of the sun's surface, facing heat and radiation like no spacecraft before it. The mission will provide new data on solar activity to help us better understand our home star and its activity - information that can improve forecasts of major space-weather events that could impact life on Earth.

3. Majorly Massive 

The sun is the center of our solar system and makes up 99.8 percent of the mass of the entire solar system. If the sun were as tall as a typical front door, Earth would be about the size of a nickel.

4. Different Spin 

Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 days, but at its poles the sun rotates once on its axis every 36 Earth days.

5. Can't Stand on It

The sun is a star and a star doesn't have a solid surface. Rather, it's a ball of ionized gas 92.1% hydrogen (H2) and 7.8% helium (He) held together by its own gravity.

6. Center of Attention 

The sun isn't a planet, so it doesn't have any moons. But, the sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and hundreds of thousands to trillions of comets and icy bodies.

7. It's Hot in There 

And we mean really, really hot. The temperature at the sun's core is about 27 million degrees Fahrenheit. However, its atmosphere, the corona, can reach temperatures of 3 million degrees. (That's as if it got hotter the farther away you got from a fire, instead of cooler!) Parker Solar Probe will help scientists solve the mystery of why the corona's temperature is so much higher than the surface.

8. Travel Conditions

The sun influences the entire solar system, so studying it helps us better understand the space weather that our astronauts and spacecraft travel through.

9. Life on the Sun? 

Better to admire from afar. Thanks to its hot, energetic mix of gases and plasma, the sun can't be home to living things. However, we can thank the sun for making life on Earth possible by providing the warmth and energy that supply Earth’s food chain.

10. Chance of a Lifetime 

Last but not least, don't forget that the first total solar eclipse to sweep across the U.S. from coast-to-coast since 1918 is happening on August 21, 2017. Our toolkit has you need to know to about it. 

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

Parker Solar Probe: Sun’s Secret Particle Source Revealed!

NASA's Parker Solar Probe has made a groundbreaking discovery by identifying a new source of energetic particles near the Sun. As the probe ventured into the solar corona—the Sun’s outer atmosphere—it captured definitive evidence of these high-energy phenomena. This insight helps explain how solar energetic particles are accelerated, potentially affecting space weather and satellite operations. The discovery marks a significant advancement in solar science, shedding light on particle generation mechanisms close to our star and bringing us closer to understanding solar storms and their impact on Earth and beyond.

RT - India’s landmark Sun probe reaches final destination: