A large tear-drop shaped balloon towers above surrounding work trucks on a flat expanse of snow.

Get to know GUSTO and learn how to bring the science and engineering behind this unique balloon-based mission into the classroom.


A NASA balloon mission designed to study the interstellar medium – the space between stars – will take to the skies above Antarctica in December 2023.

Read on to learn how the GUSTO mission's unique design and science goals can serve as real-life examples of STEM concepts. Then, explore lessons and resources you can use to get students learning more.

What the GUSTO Mission Will Do

Though many people think of space as empty except for things like stars, planets, moons, asteroids, meteors, and comets, it’s anything but. Typically, there is one molecule of matter in every cubic centimeter of the space between stars known as the interstellar medium. In more dense clouds of interstellar gas, there could be as many as 1,000,000 molecules per cubic centimeter. It might not seem like much compared with the 10,000,000,000,000,000,000 molecules in every cubic centimeter of air we breathe, but the interstellar medium can tell us a lot about how stars and planets form and what role gases and dust play in our galaxy and others.

Star-forming nebulas birth Sun-like stars, which turn into red giants, then planetary nebulae, then white dwarfs. Massive stars are also born from star-forming nebulas and become red supergiants, then supernova, then either black holes or neutron stars.

This diagram shows the life cycles of Sun-like and massive stars. Credit: NASA, Night Sky Network | › Learn more about star life cycles

Like plants and animals, stars have a life cycle that scientists want to better understand. Gases and dust grains that make up a dense interstellar cloud, known as a nebula, can become disturbed, and under the pull of their own gravity, begin collapsing in on themselves. Eventually stars form from the gas and planets form from the dust. As a star goes through its life, it eventually runs out of sources of energy. When this happens, the star dies, expelling gases – sometimes violently, as in a supernova – into a new gas cloud. From here, the cycle can start again. Scientists want to know more about the many factors at play in this cycle. This is where GUSTO comes in.

GUSTO – short for Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory – is a balloon-based telescope that will study the interstellar medium, the small amount of gas and dust between the stars. From its vantage point high above almost all of the Earth’s atmosphere, GUSTO will measure carbon, nitrogen, and oxygen emissions in the far-infrared portion of the electromagnetic spectrum, focusing its sights on the Milky Way galaxy and the nearby galaxy known as the Large Magellanic Cloud.

A speckled field of bluish stars is intersected by a diagonal strip of purple and brown clouds covering a glowing yellow band beyond.

Our galaxy, the Milky Way, has hundreds of billions of stars and enough gas and dust to make billions more stars. Credit: NASA | › Full image and caption

The mission is designed to provide scientists with data that will help them understand the complete lifecycle of the gas and dust that forms planets and stars. To achieve its goals, GUSTO will study:

  • The composition and formation of molecular clouds in these regions.
  • The formation, birth, and evolution of stars from molecular clouds.
  • The formation of gas clouds following the deaths of stars. And the re-start of this cycle.
Thick clouds of purple and pastel pink cover a speckled field of stars with clusters of large and especially bright blue and yellow stars glowing through the clouds.

Nearly 200,000 light-years from Earth, the Large Magellanic Cloud is a satellite galaxy of the Milky Way. Vast clouds of gas within it slowly collapse to form new stars. In turn, these light up the gas clouds in a riot of colors, visible in this image from the Hubble Space Telescope. Credit: NASA | › Full image and caption

Scientists hope to use the information collected by GUSTO to develop models of the Milky Way and Large Magellanic Cloud. Studying these two galaxies allows scientists to observe more details and make more accurate models. Those models can then be used for comparing and studying more distant galaxies that are harder to observe.

Why Fly on a Balloon?

Unlike most NASA missions, GUSTO won’t launch on a rocket. It will be carried to approximately 120,000 feet (36.5 kilometers) above Antarctica using what’s known as a Long Duration Balloon, or LDB.

Balloon missions provide a number of advantages to scientists conducting research. They are more affordable than missions that go to space and require less time to develop. They also offer a way to test new scientific instruments and technologies before they are used in space. For these reasons, balloons have become a popular way for university students to gain experience building and testing science instruments.

Explore how balloons are being used for Earth and space science in this video from the Johns Hopkins Applied Physics Laboratory, which is providing the mission operations for GUSTO and the balloon gondola where the mission's instruments will be mounted. | Watch on YouTube

GUSTO's use of the Long Duration Balloon provided by NASA’s Balloon Science Program offers several advantages over other types of scientific balloons. Conventional scientific balloons stay aloft for a few hours or a few days and rely on the balloon maintaining a line-of-sight to send and receive data. Long Duration Balloons use satellites for sending data and receiving commands and can stay afloat for a few weeks to a couple of months.

Made with a thin, strong, plastic film called polyethylene, LDBs are partially inflated with helium. As the balloon rises, the surrounding air pressure decreases, allowing the gas inside the balloon to expand, increasing the volume and pressure of the balloon. When fully expanded, the balloon has a volume of around 40 million cubic feet (1.1 million cubic meters). That’s big enough to fit an entire football stadium inside.

An A-frame support structure with two sets of wing-like solar panels extending from its sides floats above Earth holding a telescope at its center.

GUSTO will be attached to a balloon gondola like the one depicted in this artist's rendering. | + Expand image

The telescope itself will be attached to a platform known as a gondola, which is home to several components that make the mission possible. The multi-axis control system will keep the platform stable during flight, allowing for precisely pointing GUSTO’s 35-inch (90-centimeter) diameter telescope in the right direction. Cryocoolers and liquid helium will keep the telescope’s scientific instruments at the necessary low temperature of -452°F (4° Kelvin). And the gondola will house a radio system that allows operators on the surface to control the balloon and telescope. All these systems will be powered by lithium-ion batteries charged during flight by a set of solar arrays.

Location is Everything

GUSTO is designed to measure terahertz wavelengths (in the far-infrared portion of the electromagnetic spectrum), a range of energy that is easily absorbed by water vapor. However, the observatory's altitude will put it in the upper half of the stratosphere and above 99% of the water vapor in the atmosphere. This makes it an ideal location for the mission to make its measurements and avoid factors that might otherwise obstruct its view.

GUSTO will make its observations from the upper half of the stratosphere, which offers several benefits over observing from lower in the atmosphere or from the ground. Credit: NASA | › Explore the interactive graphic

The stratosphere offers another advantage for GUSTO. This layer of the atmosphere warms as altitude increases, making the top of the stratosphere warmer than the bottom. The colder air at the bottom and warmer air at the top prevents mixing and air turbulence, making the air very stable and providing a great place to observe space. You may have noticed this stability if you’ve seen a flat-topped anvil-shaped storm cloud. That flat top is the cloud reaching the bottom of the stratosphere, where the stable air prevents the cloud from mixing upward.

But why fly GUSTO above Antarctica? Even though balloons can be launched from all over the planet, the 24 hours of sunlight per day provided by the Antarctic summer make the south polar region an ideal launch location for a solar-powered mission like GUSTO. But more important is a weather phenomenon known as an anticyclone. This weather system is an upper-atmosphere counter-clockwise wind flow that circles the South Pole about every two weeks. The Antarctic anticyclone allows for long balloon flights of missions that can be recovered and potentially reflown.

Preparing for Liftoff

To launch a balloon mission in Antarctica, weather conditions have to be just right. The anticyclone typically forms in mid-December but can arrive a little earlier or a little later. Even with the anticyclone started, winds on the ground and in the first few hundred feet of the atmosphere need to be under six knots (seven miles per hour) for GUSTO to launch. A NASA meteorologist provides daily updates on the cyclone and the ground.

Once weather conditions are good and the balloon is launched, it will circle Antarctica about once every 14 days with the wind. The anticyclone typically lasts one to two months. Because GUSTO may be in the air for more than two months, it’s possible that the mission will continue after the anticyclone ends, causing the balloon to drift northward as winter progresses.

Bring GUSTO Into the Classroom

The GUSTO mission is a great opportunity to engage students with hands-on learning opportunities. Students can build a planetary exploration balloon and model how interstellar dust forms into planets. Explore these lessons and resources to get students excited about the STEM involved in the mission.

Resources for Educators

Resources for Students


NASA's Universe of Learning materials are based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, and the Jet Propulsion Laboratory.

TAGS: GUSTO, Astronomy, Astrophysics, Science, Teaching, Learning, K-12, Classroom, Teachable Moments, Universe of Learning, Balloon Mission, Missions

  • Lyle Tavernier
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Collage of top 10 educational resources from NASA/JPL for 2021

In 2021, we added nearly 80 STEM education resources to our online catalog of lessons, activities, articles, and videos for educators, students, and families. The resources feature NASA's latest missions exploring Earth, the Moon, Mars, asteroids, the Solar System and the universe beyond. Here are the 10 resources our audiences visited most this year.


Collage of people participating in the Mission to Mars Student Challenge

NASA's Mission to Mars Student Challenge

To kick off the year, we invited students, educators, and families from around the world to create their own mission to Mars as we counted down to the Perseverance rover's epic landing on the Red Planet in February. More than one million students participated in the Mission to Mars Student Challenge, which features seven weeks of guided education plans, student projects, and expert talks and interviews highlighting each phase of a real Mars mission.

It's no surprise that this was our most popular product of the year. And good news: It's still available and timely! With Perseverance actively exploring Mars and making new discoveries all the time, the challenge offers ongoing opportunities to get students engaged in real-world STEM.

Need a primer on the Perseverance Mars rover mission, first? This article from our Teachable Moments series has you covered.


Animated image showing the planets at their relative distances.

Solar System Size and Distance

This video offers a short and simple answer to two of students' most enduring questions: How do the sizes of planets compare and how far is it between them? Plus, it gets at why we don't often (or ever) see images that show all the planets' sizes and distances to scale. Spoiler alert: It's pretty much impossible to do.

Get students exploring solar system size and distance in more detail and even making their own scale models with this student project.


Animated screenshot of an example Mars Helicopter Video Game on Scratch

Code a Mars Helicopter Video Game

As you'll soon see from the rest of this list, coding projects were a big draw this year. This one took off along with Ingenuity, the first helicopter designed to fly on Mars, which made its historic first flight in April. Designed as a test of technology that could be used on future missions, Ingenuity was only slated for a few flights, but it has far exceeded even that lofty goal.

In this project, students use the free visual programming language Scratch to create a game inspired by the helicopter-that-could.


A person holds the Moon phases calendar out in front of them.

Make a Moon Phases Calendar and Calculator

Just updated for 2022, this project is part educational activity and part art for your walls. Students learn about moon phases to complete this interactive calendar, which shows when and where to see moon phases throughout the year, plus lists moon events such as lunar eclipses and supermoons. The art-deco inspired design might just have you wanting to make one for yourself, too.


NASA Pi Day Challenge illustration

The NASA Pi Day Challenge

This year marked the eighth installment of our annual Pi Day Challenge, a set of illustrated math problems featuring pi (of course) and NASA missions and science. Don't let the name fool you – these problems are fun to solve year round.

Students can choose from 32 different problems that will develop their math skills while they take on some of the same challenges faced by NASA scientists and engineers. New this year are puzzlers featuring the OSIRIS-REx asteroid mission, Mars helicopter, Deep Space Network, and aurora science.

Educator guides for each problem and problem set are also available here. And don't miss the downloadable posters and virtual meeting backgrounds.


Animated image showing a Mars image with a cartoon rover moving across the surface collecting sample tube icons

Code a Mars Sample Collection Video Game

Another coding challenge using the visual programming language Scratch, this project is inspired by the Perseverance Mars rover mission, which is collecting samples that could be brought back to Earth by a potential future mission.

While developing a gamified version of the process, students are introduced to some of the considerations scientists and engineers have to make when collecting samples on Mars.


Animation showing the Perseverance Mars rover aeroshell descending on Mars and the parachute deploying

Code a Mars Landing

As if launching a rover to Mars wasn't hard enough, you still have to land when you get there. And that means using a complex series of devices – from parachutes to jet packs to bungee cords – and maneuvers that have to be performed remotely using instructions programmed into the spacecraft's computer.

Students who are ready to take their programming skills to the next level can get an idea of what it takes in this project, which has them use Python and microcontrollers to simulate the process of landing a rover on Mars.


Coins stacked on top of a printed map of the Los Angeles area.

How Far Away is Space?

Without giving the answer away: It's not as far as you might think.

In this activity, students stack coins (or other objects) on a map of their local area as a scale model of the distance to space. The stacking continues to the International Space Station, the Moon, and finally to the future orbit of the James Webb Space Telescope, which is slated to launch on Dec. 22.


A person puts a shape onto the tangram rover outline.

Build a Rover and More With Shapes

You don't have to be a big kid to start learning about space exploration. This activity, which is designed for kids in kindergarten through second grade, has learners use geometric shapes called tangrams to fill in a Mars rover design. It provides an introduction to geometry and thinking spatially.

Once kids become experts at building rovers, have them try building rockets.


A person holds seven cards over the Space Voyagers game mat.

Space Voyagers: The Game

Technically a classroom activity (it is standards-aligned, after all), this game will appeal to students and strategy card game enthusiasts alike. Download and print out a set for your classroom (or your next game night).

Players work collaboratively to explore destinations including the Moon, Mars, Jupiter and Jupiter's Moon Europa with actual NASA spacecraft and science instruments while working to overcome realistic challenges at their destination including dust storms and instrument failures.

TAGS: K-12, Lessons, Activities, Education Resources, Teachers, Students, Families, Kids, Learning, STEM, Science, Engineering, Technology, Math, Coding, Programming, Mars, Solar System, Moon

  • Kim Orr
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