This winter, our scientists and engineers traveled to the world’s northernmost civilian town to launch rockets equipped with cutting-edge scientific instruments.

This is the beginning of a 14-month-long campaign to study a particular region of Earth’s magnetic field — which means launching near the poles. What’s it like to launch a science rocket in these extreme conditions?

Our planet is protected by a natural magnetic field that deflects most of the particles that flow out from the Sun — the solar wind — away from our atmosphere. But near the north and south poles, two oddities in Earth’s magnetic field funnel these solar particles directly into our atmosphere. These regions are the polar cusps, and it turns out they’re the ideal spot for studying how our atmosphere interacts with space.

The scientists of the Grand Challenge Initiative — Cusp are using sounding rockets to do their research. Sounding rockets are suborbital rockets that launch to a few hundred miles in altitude, spending a few minutes in space before falling back to Earth. That means sounding rockets can carry sensitive instruments above our atmosphere to study the Sun, other stars and even distant galaxies.

They also fly directly through some of the most interesting regions of Earth’s atmosphere, and that’s what scientists are taking advantage of for their Grand Challenge experiments.

One of the ideal rocket ranges for cusp science is in Ny-Ålesund, Svalbard, off the coast of Norway and within the Arctic circle. Because of its far northward position, each morning Svalbard passes directly under Earth’s magnetic cusp.

But launching in this extreme, remote environment puts another set of challenges on the mission teams. These launches need to happen during the winter, when Svalbard experiences 24/7 darkness because of Earth’s axial tilt. The launch teams can go months without seeing the Sun.

Like for all rocket launches, the science teams have to wait for the right weather conditions to launch. Because they’re studying upper atmospheric processes, some of these teams also have to wait for other science conditions, like active auroras. Auroras are created when charged particles collide with Earth’s atmosphere — often triggered by solar storms or changes in the solar wind — and they’re related to many of the upper-atmospheric processes that scientists want to study near the magnetic cusp.

But even before launch, the extreme conditions make launching rockets a tricky business — it’s so cold that the rockets must be encased in styrofoam before launch to protect them from the low temperatures and potential precipitation.

When all is finally ready, an alarm sounds throughout the town of Ny-Ålesund to alert residents to the impending launch. And then it’s up, up and away! This photo shows the launch of the twin VISIONS-2 sounding rockets on Dec. 7, 2018 from Ny-Ålesund.

These rockets are designed to break up during flight — so after launch comes clean-up. The launch teams track where debris lands so that they can retrieve the pieces later.

The next launch of the Grand Challenge Initiative is AZURE, launching from Andøya Space Center in Norway in March 2019.

 For even more about what it’s like to launch science rockets in extreme conditions, check out one scientist’s notes from the field: https://go.nasa.gov/2QzyjR4

For updates on the Grand Challenge Initiative and other sounding rocket flights, visit nasa.gov/soundingrockets or follow along with NASA Wallops and NASA heliophysics on Twitter and Facebook.

@NASA_Wallops | NASA’s Wallops Flight Facility | @NASASun | NASA Sun Science

You may have seen the famous blue marble or pale blue dot images showing Earth from 18,000 and 3.7 billion miles away, respectively. But closer to home — some 300 miles above Earth’s surface — you might encounter an unfamiliar sight: vibrant swaths of red and green or purple and yellow light emanating from the upper atmosphere.

This light is airglow.

Airglow is created when atoms and molecules in the upper atmosphere, excited by sunlight, emit light to shed excess energy. Or, it can happen when atoms and molecules that have been ionized by sunlight collide with and capture a free electron. In both cases, these atmospheric particles emit light in order to relax again. The process is similar to how auroras are created, but while auroras are driven by high-energy solar wind, airglow is energized by day-to-day solar radiation.

Since sunlight is constant, airglow constantly shines throughout Earth’s atmosphere, and the result is a tenuous bubble of light that closely encases our planet. Its light is too dim to see easily except in orbit or on the ground with clear, dark skies and a sensitive camera — it’s one-tenth as bright as the light given off by all the stars in the night sky.  

Airglow highlights a key part of our atmosphere: the ionosphere. Stretching from roughly 50 to 400 miles above Earth’s surface, the ionosphere is an electrified layer of the upper atmosphere generated by extreme ultraviolet radiation from the Sun. It reacts to both terrestrial weather below and solar energy streaming in from above, forming a complex space weather system. Turbulence in this ever-changing sea of charged particles can manifest as disruptions that interfere with Earth-orbiting satellites or communication and navigation signals.

Understanding the ionosphere’s extreme variability is tricky because it requires untangling interactions between the different factors at play — interactions of which we don’t have a clear picture. That’s where airglow comes in. Each atmospheric gas has its own favored airglow color, hangs out at a different height and creates airglow by a different process, so we can use airglow to study different layers of the atmosphere.

Airglow carries information on the upper atmosphere’s temperature, density, and composition, but it also helps us trace how particles move through the region itself. Vast, high-altitude winds sweep through the ionosphere, pushing its contents around the globe — and airglow’s subtle dance follows their lead, highlighting global patterns.

Two NASA missions take advantage of precisely this effect to study the upper atmosphere: ICON — short for Ionospheric Connection Explorer — and GOLD — Global-scale Observations of the Limb and Disk.

ICON focuses on how charged and neutral gases in the upper atmosphere behave and interact, while GOLD observes what drives change — the Sun, Earth’s magnetic field or the lower atmosphere — in the region.

By imaging airglow, the two missions will enable scientists to tease out how space and Earth’s weather intersect, dictating the region’s complex behavior.

Keep up with the latest in NASA’s airglow and upper atmosphere research on Twitter and Facebook or at nasa.gov/sunearth.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

On Aug. 12, 2018, we launched Parker Solar Probe to the Sun, where it will fly closer than any spacecraft before and uncover new secrets about our star. Here’s what you need to know.

1. Getting to the Sun takes a lot of power

At about 1,400 pounds, Parker Solar Probe is relatively light for a spacecraft, but it launched to space aboard one of the most powerful rockets in the world, the United Launch Alliance Delta IV Heavy. That’s because it takes a lot of energy to go to the Sun — in fact, 55 times more energy than it takes to go to Mars.

Any object launched from Earth starts out traveling at about the same speed and in the same direction as Earth — 67,000 mph sideways. To get close to the Sun, Parker Solar Probe has to shed much of that sideways speed, and a strong launch is good start.

2. First stop: Venus!

Parker Solar Probe is headed for the Sun, but it’s flying by Venus along the way. This isn’t to see the sights — Parker will perform a gravity assist at Venus to help draw its orbit closer to the Sun. Unlike most gravity assists, Parker will actually slow down, giving some orbital energy to Venus, so that it can swing closer to the Sun.

One’s not enough, though. Parker Solar Probe will perform similar maneuvers six more times throughout its seven-year mission!

3. Closer to the Sun than ever before

At its closest approach toward the end of its seven-year prime mission, Parker Solar Probe will swoop within 3.83 million miles of the solar surface. That may sound pretty far, but think of it this way: If you put Earth and the Sun on opposite ends of an American football field, Parker Solar Probe would get within four yards of the Sun’s end zone. The current record-holder was a spacecraft called Helios 2, which came within 27 million miles, or about the 30 yard line. Mercury orbits at about 36 million miles from the Sun.

This will place Parker well within the Sun’s corona, a dynamic part of its atmosphere that scientists think holds the keys to understanding much of the Sun’s activity.

4. Faster than any human-made object

Parker Solar Probe will also break the record for the fastest spacecraft in history. On its final orbits, closest to the Sun, the spacecraft will reach speeds up to 430,000 mph. That’s fast enough to travel from New York to Tokyo in less than a minute!

5. Dr. Eugene Parker, mission namesake

Parker Solar Probe is named for Dr. Eugene Parker, the first person to predict the existence of the solar wind. In 1958, Parker developed a theory showing how the Sun’s hot corona — by then known to be millions of degrees Fahrenheit — is so hot that it overcomes the Sun’s gravity. According to the theory, the material in the corona expands continuously outwards in all directions, forming a solar wind.

This is the first NASA mission to be named for a living person, and Dr. Parker watched the launch with the mission team from Kennedy Space Center in Florida.

6. Unlocking the secrets of the solar wind

Even though Dr. Parker predicted the existence of the solar wind 60 years ago, there’s a lot about it we still don’t understand. We know now that the solar wind comes in two distinct streams, fast and slow. We’ve identified the source of the fast solar wind, but the slow solar wind is a bigger mystery.

Right now, our only measurements of the solar wind happen near Earth, after it has had tens of millions of miles to blur together, cool down and intermix. Parker’s measurements of the solar wind, just a few million miles from the Sun’s surface, will reveal new details that should help shed light on the processes that send it speeding out into space.

7. Studying near-light speed particles

Another question we hope to answer with Parker Solar Probe is how some particles can accelerate away from the Sun at mind-boggling speeds — more than half the speed of light, or upwards of 90,000 miles per second. These particles move so fast that they can reach Earth in under half an hour, so they can interfere with electronics on board satellites with very little warning.

8. The mystery of the corona’s high heat

The third big question we hope to answer with this mission is something scientists call the coronal heating problem. Temperatures in the Sun’s corona, where Parker Solar Probe will fly, spike upwards of 2 million degrees Fahrenheit, while the Sun’s surface below simmers at a balmy 10,000 F. How the corona gets so much hotter than the surface remains one of the greatest unanswered questions in astrophysics.

Though scientists have been working on this problem for decades with measurements taken from afar, we hope measurements from within the corona itself will help us solve the coronal heating problem once and for all.

9. Why won’t Parker Solar Probe melt?

The corona reaches millions of degrees Fahrenheit, so how can we send a spacecraft there without it melting?

The key lies in the distinction 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 incredibly thin, 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.

10. Engineered to thrive in an extreme environment

Make no mistake, the environment in the Sun’s atmosphere is extreme — hot, awash in radiation, and very far from home — but Parker Solar Probe is engineered to survive.

The spacecraft is outfitted with a cutting-edge heat shield made of a carbon composite foam sandwiched between two carbon plates. The heat shield is so good at its job that, even though the front side will receive the full brunt of the Sun’s intense light, reaching 2,500 F, the instruments behind it, in its shadow, will remain at a cozy 85 F.

Even though Parker Solar Probe’s solar panels — which provide the spacecraft’s power — are retractable, even the small bit of surface area that peeks out near the Sun is enough to make them prone to overheating. So, to keep its cool, Parker Solar Probe circulates a single gallon of water through the 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.

For much of its journey, Parker Solar Probe will be too far from home and too close to the Sun for us to command it in real time — but don’t worry, Parker Solar Probe can think on its feet. 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.

Read the web version of this week’s “Solar System: 10 Things to Know” article HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Tomorrow, Aug. 11, we’re launching a spacecraft to touch the Sun.

The first chance to launch Parker Solar Probe is 3:33 a.m. EDT on Aug. 11 from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida. Launch coverage on NASA TV starts at 3 a.m. EDT at nasa.gov/live.

After launch, Parker Solar Probe begins its daring journey to the Sun’s atmosphere, or corona, going closer to the Sun than any spacecraft in history and facing brutal heat and radiation.

Though Parker Solar Probe weighs a mere 1,400 pounds — pretty light for a spacecraft — it’s launching aboard one of the world’s most powerful rockets, a United Launch Alliance Delta IV Heavy with a third stage added.

Even though you might think the Sun’s massive means things would just fall into it, it’s surprisingly difficult to actually go there. Any object leaving Earth starts off traveling at about 67,000 miles per hour, same as Earth — and most of that is in a sideways direction, so you have to shed most of that sideways speed to make it to the Sun. All that means that it takes 55 times more launch energy to go to the Sun than it does to go to Mars. On top of its powerful launch vehicle, Parker Solar Probe will use seven Venus gravity assists to shed sideways speed.

Even though Parker Solar Probe will lose a lot of sideways speed, it’ll still be going incredibly fast as its orbit draws closer to the Sun throughout its seven-year mission. At its fastest, Parker Solar Probe will travel at 430,000 miles per hour — fast enough to get from Philadelphia to Washington, D.C. in one second — setting the record for the fastest spacecraft in history.

But the real challenge was to keep the spacecraft from frying once it got there.

We’ve always wanted to send a mission to the corona, but we literally haven’t had the technology that can protect a spacecraft and its instruments from its scorching heat. Only recent advances have enabled engineers to build a heat shield that will protect the spacecraft on this journey of extremes — a tricky feat that requires withstanding the Sun’s intense radiation on the front and staying cool at the back, so the spacecraft and instruments can work properly.

The 4.5-inches-thick heat shield is built like a sandwich. There’s a thin layer of carbon material like you might find in your golf clubs or tennis rackets, carbon foam, and then another thin piece of carbon-carbon on the back. Even while the Sun-facing side broils at 2,500 degrees Fahrenheit, the back of the shield will remain a balmy 85 degrees — just above room temperature. There are so few particles in this region that it’s a vacuum, so blocking the Sun’s radiation goes a long way towards keeping the spacecraft cool.

Parker Solar Probe is also our first mission to be named after a living individual: Dr. Eugene Parker, famed solar physicist who in 1958 first predicted the existence of the solar wind.

“Solar wind” is what Dr. Parker dubbed the stream of charged particles that flows constantly from the Sun, bathing Earth and our entire solar system in the Sun’s magnetic fields. Parker Solar Probe’s flight right through the corona allows it to observe the birth of the very solar wind that Dr. Parker predicted, right as it speeds up and over the speed of sound.  

The corona is where solar material is heated to millions of degrees and where the most extreme eruptions on the Sun occur, like solar flares and coronal mass ejections, which fling particles out to space at incredible speeds near the speed of light. These explosions can also spark space weather storms near Earth that can endanger satellites and astronauts, disrupt radio communications and, at their most severe, trigger power outages.

Thanks to Parker Solar Probe’s landmark mission, solar scientists will be able to see the objects of their study up close and personal for the very first time.

Up until now, all of our studies of the corona have been remote — that is, taken from a distance, rather than at the mysterious region itself. Scientists have been very creative to glean as much as possible from their remote data, but there’s nothing like actually sending a probe to the corona to see what’s going on.

And scientists aren’t the only ones along for the adventure — Parker Solar Probe holds a microchip carrying the names of more than 1.1 million people who signed up to send their name to the Sun. This summer, these names and 1,400 pounds of science equipment begin their journey to the center of our solar system.

Three months later in November 2018, Parker Solar Probe makes its first close approach to the Sun, and in December, it will send back the data. The corona is one of the last places in the solar system where no spacecraft has visited before; each observation Parker Solar Probe makes is a potential discovery.

Stay tuned — Parker Solar Probe is about to take flight.

Keep up with the latest on the mission at nasa.gov/solarprobe or follow us on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.