Thehkr - 無標題

Roman's primary structure hangs from cables as it moves into the big clean room at NASA's Goddard Space Flight Center.

What Makes the Clean Room So Clean?

When you picture NASA’s most important creations, you probably think of a satellite, telescope, or maybe a rover. But what about the room they’re made in? Believe it or not, the room itself where these instruments are put together—a clean room—is pretty special. 

A clean room is a space that protects technology from contamination. This is especially important when sending very sensitive items into space that even small particles could interfere with.

There are two main categories of contamination that we have to keep away from our instruments. The first is particulate contamination, like dust. The second is molecular contamination, which is more like oil or grease. Both types affect a telescope’s image quality, as well as the time it takes to capture imagery. Having too many particles on our instruments is like looking through a dirty window. A clean room makes for clean science!

Two technicians clean the floor of Goddard’s big clean room.

Our Goddard Space Flight Center in Greenbelt, Maryland has the largest clean room of its kind in the world. It’s as tall as an eight-story building and as wide as two basketball courts.

Goddard’s clean room has fewer than 3,000 micron-size particles per cubic meter of air. If you lined up all those tiny particles, they’d be no longer than a sesame seed. If those particles were the size of 16-inch (0.4-meter) inflatable beach balls, we’d find only 3,000 spread throughout the whole body of Mount Everest!

A clean room technician observes a sample under a microscope.

The clean room keeps out particles larger than five microns across, just seven percent of the width of an average human hair. It does this via special filters that remove around 99.97% of particles 0.3 microns and larger from incoming air. Six fans the size of school buses spin to keep air flowing and pressurize the room. Since the pressure inside is higher, the clean air keeps unclean air out when doors open.

A technician analyzes a sample under ultraviolet light.

In addition, anyone who enters must wear a “bunny suit” to keep their body particles away from the machinery. A bunny suit covers most of the person inside. Sometimes scientists have trouble recognizing each other while in the suits, but they do get to know each other’s mannerisms very well.

This illustration depicts the anatomy of a bunny suit, which covers clean room technicians from head to toe to protect sensitive technology.

The bunny suit is only the beginning: before putting it on, team members undergo a preparation routine involving a hairnet and an air shower. Fun fact – you’re not allowed to wear products like perfume, lotion, or deodorant. Even odors can transfer easily!

Six of Goddard’s clean room technicians (left to right: Daniel DaCosta, Jill Bender, Anne Martino, Leon Bailey, Frank D’Annunzio, and Josh Thomas).

It takes a lot of specialists to run Goddard’s clean room. There are 10 people on the Contamination Control Technician Team, 30 people on the Clean Room Engineering Team to cover all Goddard missions, and another 10 people on the Facilities Team to monitor the clean room itself. They check on its temperature, humidity, and particle counts.

A technician rinses critical hardware with isopropyl alcohol and separates the particulate and isopropyl alcohol to leave the particles on a membrane for microscopic analysis.

Besides the standard mopping and vacuuming, the team uses tools such as isopropyl alcohol, acetone, wipes, swabs, white light, and ultraviolet light. Plus, they have a particle monitor that uses a laser to measure air particle count and size.

The team keeping the clean room spotless plays an integral role in the success of NASA’s missions. So, the next time you have to clean your bedroom, consider yourself lucky that the stakes aren’t so high!

Make sure to follow us on Tumblr for your regular dose of space!

The Perseid Meteor Shower Is Here!

Image Credit: NASA/Bill Ingalls 

The Perseids are at their peak this week!

The Perseid meteor shower, one of the biggest meteor showers of the year, will be at its brightest early in the morning on Wednesday, August 12. Read on for some tips on how to watch the night sky this week – and to find out: what exactly are the Perseids, anyway?

Credit: NASA/Bill Ingalls

Your best chance to spot the Perseids will be between 2 AM and dawn (local time) the morning of August 12. Find a dark spot, avoid bright lights (yes, that includes your phone) and get acclimated to the night sky.

Your eyes should be at peak viewing capacity after about 30 minutes; though the Moon may block out some of the dimmer meteors, you should still be able to see up to 15-20 an hour. If you’re not an early bird, you can try and take a look soon after sunset (around 9 PM) on the 11th, though you may not see as many Perseids then.

Credit: NASA/MEO

If it’s too cloudy, or too bright, to go skywatching where you are, you can try again Wednesday or Thursday night – or just stay indoors and watch the Perseids online!

Our Meteor Watch program will be livestreaming the Perseids from Huntsville, Alabama on Facebook (weather permitting), [link to come] starting around 9 p.m. EDT on August 11 and continuing through sunrise.

So… why are they called the Perseids?

Because all of a meteor shower’s meteors have similar orbits, they appear to come from the same place in the sky – a point called the radiant. 

The radiant for the Perseids, as you might guess from the name, is in the constellation Perseus, found near Aries and Taurus in the night sky.

But they’re not actually coming from Perseus, right?

Credit: NASA/Joel Kowsky

Right! The Perseids are actually fragments of the comet Swift-Tuttle, which orbits within our solar system.

If you want to learn more about the Perseids, visit our Watch the Skies blog or check out our monthly “What’s Up” video series. Happy viewing!

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

“Sometimes people with the worst past end up creating the best future.”

— Unknown

Cosmic Alphabet Soup: Classifying Stars

If you’ve spent much time stargazing, you may have noticed that while most stars look white, some are reddish or bluish. Their colors are more than just pretty – they tell us how hot the stars are. Studying their light in greater detail can tell us even more about what they’re like, including whether they have planets. Two women, Williamina Fleming and Annie Jump Cannon, created the system for classifying stars that we use today, and we’re building on their work to map out the universe.

By splitting starlight into spectra – detailed color patterns that often feature lots of dark lines – using a prism, astronomers can figure out a star’s temperature, how long it will burn, how massive it is, and even how big its habitable zone is. Our Sun’s spectrum looks like this:

Astronomers use spectra to categorize stars. Starting at the hottest and most massive, the star classes are O, B, A, F, G (like our Sun), K, M. Sounds like cosmic alphabet soup! But the letters aren’t just random – they largely stem from the work of two famous female astronomers.

Williamina Fleming, who worked as one of the famous “human computers” at the Harvard College Observatory starting in 1879, came up with a way to classify stars into 17 different types (categorized alphabetically A-Q) based on how strong the dark lines in their spectra were. She eventually classified more than 10,000 stars and discovered hundreds of cosmic objects!

That was back before they knew what caused the dark lines in spectra. Soon astronomers discovered that they’re linked to a star’s temperature. Using this newfound knowledge, Annie Jump Cannon – one of Fleming’s protégés – rearranged and simplified stellar classification to include just seven categories (O, B, A, F, G, K, M), ordered from highest to lowest temperature. She also classified more than 350,000 stars!

Type O stars are both the hottest and most massive in the new classification system. These giants can be a thousand times bigger than the Sun! Their lifespans are also around 1,000 times shorter than our Sun’s. They burn through their fuel so fast that they only live for around 10 million years. That’s part of the reason they only make up a tiny fraction of all the stars in the galaxy – they don’t stick around for very long.

As we move down the list from O to M, stars become progressively smaller, cooler, redder, and more common. Their habitable zones also shrink because the stars aren’t putting out as much energy. The plus side is that the tiniest stars can live for a really long time – around 100 billion years – because they burn through their fuel so slowly.

Astronomers can also learn about exoplanets – worlds that orbit other stars – by studying starlight. When a planet crosses in front of its host star, different kinds of molecules in the planet’s atmosphere absorb certain wavelengths of light.

By spreading the star’s light into a spectrum, astronomers can see which wavelengths have been absorbed to determine the exoplanet atmosphere’s chemical makeup. Our James Webb Space Telescope will use this method to try to find and study atmospheres around Earth-sized exoplanets – something that has never been done before.

Our upcoming Nancy Grace Roman Space Telescope will study the spectra from entire galaxies to build a 3D map of the cosmos. As light travels through our expanding universe, it stretches and its spectral lines shift toward longer, redder wavelengths. The longer light travels before reaching us, the redder it becomes. Roman will be able to see so far back that we could glimpse some of the first stars and galaxies that ever formed.

Learn more about how Roman will study the cosmos in our other posts:

Roman’s Family Portrait of Millions of Galaxies

New Rose-Colored Glasses for Roman

How Gravity Warps Light

Make sure to follow us on Tumblr for your regular dose of space!

Meet Our Superhero Space Telescopes!

While the first exoplanets—planets beyond our solar system—were discovered using ground-based telescopes, the view was blurry at best. Clouds, moisture, and jittering air molecules all got in the way, limiting what we could learn about these distant worlds.

A superhero team of space telescopes has been working tirelessly to discover exoplanets and unveil their secrets. Now, a new superhero has joined the team—the James Webb Space Telescope. What will it find? Credit: NASA/JPL-Caltech

To capture finer details—detecting atmospheres on small, rocky planets like Earth, for instance, to seek potential signs of habitability—astronomers knew they needed what we might call “superhero” space telescopes, each with its own special power to explore our universe. Over the past few decades, a team of now-legendary space telescopes answered the call: Hubble, Chandra, Spitzer, Kepler, and TESS.

Much like scientists, space telescopes don't work alone. Hubble observes in visible light—with some special features (superpowers?)—Chandra has X-ray vision, and TESS discovers planets by looking for tiny dips in the brightness of stars.

Kepler and Spitzer are now retired, but we're still making discoveries in the space telescopes' data. Legends! All were used to tell us more about exoplanets. Spitzer saw beyond visible light into the infrared and was able to make exoplanet weather maps! Kepler discovered more than 3,000 exoplanets.

Three space telescopes studied one fascinating planet and told us different things. Hubble found that the atmosphere of HD 189733 b is a deep blue. Spitzer estimated its temperature at 1,700 degrees Fahrenheit (935 degrees Celsius). Chandra, measuring the planet’s transit using X-rays from its star, showed that the gas giant’s atmosphere is distended by evaporation.

Adding the James Webb Space Telescope to the superhero team will make our science stronger. Its infrared views in increased ranges will make the previously unseen visible.

Soon, Webb will usher in a new era in understanding exoplanets. What will Webb discover when it studies HD 189733 b? We can’t wait to find out! Super, indeed.

Make sure to follow us on Tumblr for your regular dose of space!

Setting the Standards for Unmanned Aircraft

From advanced wing designs, through the hypersonic frontier, and onward into the era of composite structures, electronic flight controls, and energy efficient flight, our engineers and researchers have led the way in virtually every aeronautic development. And since 2011, aeronautical innovators from around the country have been working on our Unmanned Aircraft Systems integration in the National Airspace System, or UAS in the NAS, project.  

This project was a new type of undertaking that worked to identify, develop, and test the technologies and procedures that will make it possible for unmanned aircraft systems to have routine access to airspace occupied by human piloted aircraft. Since the start, the goal of this unified team was to provide vital research findings through simulations and flight tests to support the development and validation of detect and avoid and command and control technologies necessary for integrating UAS into the NAS.  

That interest moved into full-scale testing and evaluation to determine how to best integrate unmanned vehicles into the national airspace and how to come up with standards moving forward. Normally, 44,000 flights safely take off and land here in the U.S., totaling more than 16 million flights per year. With the inclusion of millions of new types of unmanned aircraft, this integration needs to be seamless in order to keep the flying public safe.

Working hand-in-hand, teams collaborated to better understand how these UAS’s would travel in the national airspace by using NASA-developed software in combination with flight tests. Much of this work is centered squarely on technology called detect and avoid.  One of the primary safety concerns with these new systems is the inability of remote operators to see and avoid other aircraft.  Because unmanned aircraft literally do not have a pilot on board, we have developed concepts allowing safe operation within the national airspace.  

In order to better understand how all the systems work together, our team flew a series of tests to gather data to inform the development of minimum operational performance standards for detect and avoid alerting guidance. Over the course of this testing, we gathered an enormous amount of data allowing safe integration for unmanned aircraft into the national airspace. As unmanned aircraft are becoming more ubiquitous in our world - safety, reliability, and proven research must coexist.

Every day new use case scenarios and research opportunities arise based around the hard work accomplished by this incredible workforce. Only time will tell how these new technologies and innovations will shape our world.

Want to learn the many ways that NASA is with you when you fly? Visit nasa.gov/aeronautics.



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

Travel to Exotic Destinations in our Galaxy!

The planets beyond our solar system – exoplanets – are so far away, often trillions of miles, that we don’t have the technology to truly see them. Even the best photos show the planets as little more than bright dots. We’ve confirmed more than 5,000 exoplanets, but we think there are billions. Space telescopes like Hubble aren’t able to take photos of these far-off worlds, but by studying them in different wavelengths of light (colors), we’ve learned enough about conditions on these planets that we can illustrate them.

We know, thanks to the now-retired Spitzer Space Telescope, that there is a thick atmosphere on a planet called 55 Cancri e about 40 light-years away. And Hubble found silicate vapor in the atmosphere of this rocky world. We also know it’s scorching-close to its Sun-like star, so … lava. Lots and lots of lava. This planet is just one of the many that the James Webb Space Telescope will soon study, telling us even more about the lava world!

You can take a guided tour of this planet (and others) and see 360-degree simulations at our new Exoplanet Travel Bureau.

Travel to the most exotic destinations in our galaxy, including:

Kepler-16b, a planet with two suns.

Then there’s PSO J318.5-22, a world with no sun that wanders the galaxy alone. The nightlife would never end on a planet without a star.

TRAPPIST-1e, which will also be studied by the Webb Space Telescope, is one of seven Earth-sized planets orbiting a star about 40 light-years from Earth. It’s close enough that, if you were standing on this exoplanet, you could see our Sun as a star in the Leo constellation! You can also see it on the poster below: look for a yellow star to the right of the top person’s eye.

We haven’t found life beyond Earth (yet) but we’re looking. Meanwhile, we can imagine the possibility of red grass and other plants on Kepler-186f, a planet orbiting a red dwarf star.

We can also imagine what it might be like to skydive on a super-Earth about seven times more massive than our home planet. You would fall about 35% faster on a super-Earth like HD 40307g, making for a thrilling ride!

Any traveler is going to want to pick up souvenirs, and we have you covered. You can find free downloads of all the posters here and others! What are you waiting for? Come explore with us!

Make sure to follow us on Tumblr for your regular dose of space!

Image credits: NASA/JPL-Caltech