Wow - Blog Posts
Meet Parker Solar Probe, Our Mission to Touch the Sun
In just a few weeks, we're launching a spacecraft to get closer to the Sun than any human-made object has ever gone.
The mission, called Parker Solar Probe, is outfitted with a lineup of instruments to measure the Sun's particles, magnetic and electric fields, solar wind and more – all to help us better understand our star, and, by extension, stars everywhere in the universe.
Parker Solar Probe is about the size of a small car, and after launch – scheduled for no earlier than Aug. 6, 2018 – it will swing by Venus on its way to the Sun, using a maneuver called a gravity assist to draw its orbit closer to our star. Just three months after launch, Parker Solar Probe will make its first close approach to the Sun – the first of 24 throughout its seven-year mission.
Though Parker Solar Probe will get closer and closer to the Sun with each orbit, the first approach will already place the spacecraft as the closest-ever human-made object to the Sun, swinging by at 15 million miles from its surface. This distance places it well within the corona, a region of the Sun's outer atmosphere that scientists think holds clues to some of the Sun's fundamental physics.
For comparison, Mercury orbits at about 36 million miles from the Sun, and the previous record holder – Helios 2, in 1976 – came within 27 million miles of the solar surface.
Humanity has studied the Sun for thousands of years, and our modern understanding of the Sun was revolutionized some 60 years ago with the start of the Space Age. We've come to understand that the Sun affects Earth in more ways than just providing heat and light – it's an active and dynamic star that releases solar storms that influence Earth and other worlds throughout the solar system. The Sun's activity can trigger the aurora, cause satellite and communications disruptions, and even – in extreme cases – lead to power outages.
Much of the Sun's influence on us is embedded in the solar wind, the Sun's constant outflow of magnetized material that can interact with Earth's magnetic field. One of the earliest papers theorizing the solar wind was written by Dr. Gene Parker, after whom the mission is named.
Though we understand the Sun better than we ever have before, there are still big questions left to be answered, and that's where scientists hope Parker Solar Probe will help.
First, there's the coronal heating problem. This refers to the counterintuitive truth that the Sun's atmosphere – the corona – is much, much hotter than its surface, even though the surface is millions of miles closer to the Sun's energy source at its core. Scientists hope Parker Solar Probe's in situ and remote measurements will help uncover the mechanism that carries so much energy up into the upper atmosphere.
Second, scientists hope to better understand the solar wind. At some point on its journey from the Sun out into space, the solar wind is accelerated to supersonic speeds and heated to extraordinary temperatures. Right now, we measure solar wind primarily with a group of satellites clustered around Lagrange point 1, a spot in space between the Sun and Earth some 1 million miles from us.
By the time the solar wind reaches these satellites, it has traveled about 92 million miles already, blending together the signatures that could shed light on the acceleration process. Parker Solar Probe, on the other hand, will make similar measurements less than 4 million miles from the solar surface – much closer to the solar wind's origin point and the regions of interest.
Scientists also hope that Parker Solar Probe will uncover the mechanisms at work behind the acceleration of solar energetic particles, which can reach speeds more than half as fast as the speed of light as they rocket away from the Sun! Such particles can interfere with satellite electronics, especially for satellites outside of Earth's magnetic field.
Parker Solar Probe will launch from Space Launch Complex 37 at Cape Canaveral Air Force Station, adjacent to NASA’s Kennedy Space Center in Florida. Because of the enormous speed required to achieve its solar orbit, the spacecraft will launch on a United Launch Alliance Delta IV Heavy, one of the most powerful rockets in the world.
Stay tuned over the next few weeks to learn more about Parker Solar Probe's science and follow along with its journey to launch. We'll be posting updates here on Tumblr, on Twitter and Facebook, and at nasa.gov/solarprobe.
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A room with Earth views! 🌎 Earlier this week, astronaut Ricky Arnold captured this spectacular view of our home planet while he was orbiting at a speed of 17,500 miles per hour. If you’re wondering where in the world this video was taken, it starts as the International Space Station is above San Francisco and moving southward through the Americas.
Each day, the station completes 16 orbits of our home planet as the six humans living and working aboard our orbiting laboratory conduct important science and research. Their work will not only benefit life here on Earth, but will help us venture deeper into space than ever before.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
How does a microgravity garden grow when there's no up or down? An advanced chamber, about the size of a mini-fridge, is giving us a clearer perspective of plant growth habits. Without gravity and the addition of a wide variety of light and humidity settings, the plants cultivated on the International Space Station provide a world of opportunity to study space-based agricultural cycles.
Learn more about our space garden HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
The Beauty of Webb Telescope’s Mirrors
The James Webb Space Telescope’s gold-plated, beryllium mirrors are beautiful feats of engineering. From the 18 hexagonal primary mirror segments, to the perfectly circular secondary mirror, and even the slightly trapezoidal tertiary mirror and the intricate fine-steering mirror, each reflector went through a rigorous refinement process before it was ready to mount on the telescope. This flawless formation process was critical for Webb, which will use the mirrors to peer far back in time to capture the light from the first stars and galaxies.
The James Webb Space Telescope, or Webb, is our upcoming infrared space observatory, which will launch in 2019. It will spy the first luminous objects that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born, and how life could form on other planets.
A polish and shine that would make your car jealous
All of the Webb telescope’s mirrors were polished to accuracies of approximately one millionth of an inch. The beryllium mirrors were polished at room temperature with slight imperfections, so as they change shape ever so slightly while cooling to their operating temperatures in space, they achieve their perfect shape for operations.
The Midas touch
Engineers used a process called vacuum vapor deposition to coat Webb’s mirrors with an ultra-thin layer of gold. Each mirror only required about 3 grams (about 0.11 ounces) of gold. It only took about a golf ball-sized amount of gold to paint the entire main mirror!
Before the deposition process began, engineers had to be absolutely sure the mirror surfaces were free from contaminants.
The engineers thoroughly wiped down each mirror, then checked it in low light conditions to ensure there was no residue on the surface.
Inside the vacuum deposition chamber, the tiny amount of gold is turned into a vapor and deposited to cover the entire surface of each mirror.
Primary, secondary, and tertiary mirrors, oh my!
Each of Webb’s primary mirror segments is hexagonally shaped. The entire 6.5-meter (21.3-foot) primary mirror is slightly curved (concave), so each approximately 1.3-meter (4.3-foot) piece has a slight curve to it.
Those curves repeat themselves among the segments, so there are only three different shapes — 6 of each type. In the image below, those different shapes are labeled as A, B, and C.
Webb’s perfectly circular secondary mirror captures light from the 18 primary mirror segments and relays those images to the telescope's tertiary mirror.
The secondary mirror is convex, so the reflective surface bulges toward a light source. It looks much like a curved mirror that you see on the wall near the exit of a parking garage that lets motorists see around a corner.
Webb’s trapezoidal tertiary mirror captures light from the secondary mirror and relays it to the fine-steering mirror and science instruments. The tertiary mirror sits at the center of the telescope’s primary mirror. The tertiary mirror is the only fixed mirror in the system — all of the other mirrors align to it.
All of the mirrors working together will provide Webb with the most advanced infrared vision of any space observatory we’ve ever launched!
Who is the fairest of them all?
The beauty of Webb’s primary mirror was apparent as it rotated past a cleanroom observation window at our Goddard Space Flight Center in Greenbelt, Maryland. If you look closely in the reflection, you will see none other than James Webb Space Telescope senior project scientist and Nobel Laureate John Mather!
Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.