Icons and overlays showing an orbital path, heat map, and cat's heart rate are show over an image of an orange tabby cat laying on a gray couch and looking intently off to the side.

Find out how the now famous video beamed from space, showing a cat chasing a laser, marked a milestone for space exploration, and find resources to engage students in related STEM learning.


You may have seen in the news last month that NASA beamed a cat video from space. It was all part of a test of new technology known as Deep Space Optical Communications. While the video went down in cat video history, the NASA technology used to transmit the first ultra-high-definition video from deep space also represented a historic advancement for space exploration – the potential to stream videos from the Moon, Mars, and beyond.

Read on to learn how this new technology will revolutionize space communications. Then, explore STEM learning resources that will get students using coding, math, and engineering to explore more about how NASA communicates with spacecraft.

Why did NASA beam a cat video from space?

Communicating with spacecraft across the solar system means sending data – such as commands, images, measurements, and status reports – over enormous distances, with travel times limited by the speed of light. NASA spacecraft have traditionally used radio signals to transmit information to Earth via the Deep Space Network, or DSN. The DSN is made up of an array of giant antennas situated around the globe (in California, Spain, and Australia) that allow us to keep in contact with distant spacecraft as Earth rotates.

When scientists and engineers want to send commands to a spacecraft in deep space, they turn to the Deep Space Network, NASA’s international array of giant antennas. | Watch on YouTube

Although sending transmissions using radio frequencies works well, advances in spacecraft technology mean we're collecting and transmitting a lot more data than in the past. The more data a spacecraft collects and needs to transmit to Earth, the more time it takes to transmit that data. And with so many spacecraft waiting to take their turn transmitting via the DSN's antennas, a sort of data traffic jam is on the horizon.

This interactive shows a real-time simulated view of communications between spacecraft and the DSN. Explore more on DSN Now

To alleviate the potential traffic jam, NASA is testing technology known as optical communications, which allows spacecraft to send and receive data at a higher information rate so that each transmission takes less of the DSN’s time.

The technology benefits scientists and engineers – or anyone who is fascinated by space – by allowing robotic spacecraft exploring planets we can't yet visit in person to send high-definition imagery and stream video to Earth for further study. Optical communications could also play an important role in upcoming human missions to the Moon and eventually to Mars, which will require a lot of data transmission, including video communication.

But why transmit a video of a cat? For a test of this kind, engineers would normally send randomly generated test data. But, in this case, to mark what was a significant event for the project, the team at NASA's Jet Propulsion Laboratory worked with the center's DesignLab to create a fun video featuring the pet of a JPL employee – a now famous orange tabby named Taters – chasing a laser. The video was also a nod to the project's use of lasers (more on that in a minute) and the first television test broadcast in 1928 that featured a statue of the cartoon character Felix the Cat.

This 15-second ultra-high-definition video featuring a cat named Taters was streamed via laser from deep space by NASA on Dec. 11, 2023. | Watch on YouTube

How lasers improve spacecraft communications

The NASA project designed to test this new technology is known as Deep Space Optical Communications, or DSOC. It aims to prove that we can indeed transmit data from deep space at a higher information rate.

To improve upon the rate at which data flows between spacecraft and antennas on Earth, DSOC uses laser signals rather than the radio signals currently used to transmit data. Radio signals and laser signals are both part of the electromagnetic spectrum and travel at the same speed – the speed of light – but they have different wavelengths. The DSOC lasers transmit data in the near-infrared portion of the electromagnetic spectrum, so their wavelength is shorter than radio waves, and they have a higher frequency.

Each type of wave on the electromagnetic spectrum is represented with a wavy line. Each wave – radio, microwave, infrared, visible, ultraviolet, x-ray, and gamma ray – is between a range of wavelengths that get shorter (from >100,000,000 nm to <.01 nm) and frequencies that get higher (from <3x10^9 to >3x10^19 Hz) from left to right. Visible light makes up a relatively tiny portion of the full spectrum.

This chart compares the wavelength and frequency range of each kind of wave on the electromagnetic spectrum. Note: The graphic representations are not to scale. Image credit: NASA/JPL-Caltech | + Expand image | › Download low-ink version for printing

Since there are more infrared than radio wavelengths over a particular distance, more data can be sent over the same distance using infrared. And since the speed of infrared and radio waves is equal to the speed of light, this also means that more data can be sent in the same length of time using infrared.

As a result, DSOC’s maximum information rate is around 267 megabits per second (Mbps), faster than many terrestrial internet signals. At that high data rate, the 153.6 megabit cat video took only 0.58 seconds to transmit and another 101 seconds to travel the 19 million miles to Earth at the speed of light. Instead, if we had sent the cat video using Psyche's radio transmitter, which has a data rate of 360 kilobits per second, it would have taken 426 seconds to transmit the video, plus the same speed-of-light travel time, to get to Earth.

Here's how DSOC aims to revolutionize deep space communications. | Watch on YouTube

This kind of spacecraft communications isn't without its challenges. Accurately pointing the narrow laser beam is one of the greatest challenges of optical communications.

DSOC consists of a "flight laser transceiver" aboard the Psyche spacecraft – which is currently on its journey to study the asteroid 16-Psyche – and a receiving station on Earth. The flight transceiver is a 22-centimeter-diameter apparatus that can both transmit and receive signals. Its maximum transmitter strength is a low 4 Watts. For the December 2023 test, a 160-Watt beacon signal was transmitted to the DSOC flight transceiver by a 1-meter telescope located at JPL's Table Mountain facility near Wrightwood, California. This beacon signal was used by the Psyche spacecraft as a pointing reference so it could accurately aim the DSOC transceiver at the Earth receiving station – the 5-meter Hale telescope at Caltech’s Palomar Observatory near San Diego.

This animation shows how DSOC's laser signals are sent between the Psyche spacecraft and ground stations on Earth - first as a pointing reference to ensure accurate aiming of the narrow laser signal and then as a data transmission to the receiving station. | Watch on YouTube

When the DSOC laser beam encounters Earth, it is much narrower than a radio signal transmitted from the same distance. In fact, the laser beam is only a few hundred kilometers wide when it reaches Earth, in sharp contrast with an approximately 2.5-million-kilometer-wide radio signal. This narrow beam must be pointed accurately enough so it not only intersects Earth, but also overlaps the receiving station. To ensure that the beam will be received at Palomar Observatory, the transmission must be aimed not directly at Earth, but at a point where Earth will be in its orbit when the signal arrives after traveling the great distance from the spacecraft.

What's next for laser communications

Engineers will do additional tests of the DSOC system as the Psyche spacecraft continues its 2.2-billion-mile (3.6-billion-kilometer) journey to its destination in the asteroid belt beyond Mars. Over the next couple of years, DSOC will make weekly contacts with Earth. Visit NASA's DSOC website to follow along as NASA puts the system through its paces to potentially usher in a new means of transmitting data through space.

How does the cat video relate to STEM learning?

The DSOC project provides a wonderful opportunity to help students understand the electromagnetic spectrum and learn about real-world applications of STEM in deep space communications. Try out these lessons and resources to get students engaged.

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TAGS: K-12 Education, Educators, Students, Learning Resources, Teaching Resources, DSOC, DSN, Deep Space Network

  • Ota Lutz
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Illustration of spacecraft on a light blue background that reads "NASA Pi Day Challenge"

Cartoonish illustration of spacecraft on a dark purple background with various pi formulas

Update: March 15, 2021 – The answers are here! Visit the NASA Pi Day Challenge slideshow to view the illustrated answer keys (also available as a text-only doc) with each problem.


Learn about pi and the history of Pi Day before exploring some of the ways the number is used at NASA. Then, try the math for yourself in our Pi Day Challenge.

Infographic of all of the Pi in the Sky 7 graphics and problems

Visit the Pi in the Sky 8 lesson page to explore classroom resources and downloads for the 2021 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

In this black and white animated image, a circular device stretched out from a robotic arm descends quickly toward a rocky surface, touches it, and then ascends as debris flies all around.

Captured on Oct. 20, 2020, during the OSIRIS-REx mission’s Touch-And-Go (TAG) sample collection event, this series of images shows the SamCam imager’s field of view as the NASA spacecraft approached and touched asteroid Bennu’s surface. Image credit: NASA/Goddard/University of Arizona | › Full image and caption

On the right hand side of the image, the Perseverance Mars rover looks forward toward the camera. In the lower left, the Ingenuity helicopter sits on the surface of Mars.

NASA’s Perseverance Mars rover took a selfie with the Ingenuity helicopter, seen here about 13 feet (3.9 meters) from the rover on April 6, 2021. Image credit: NASA/JPL-Caltech/MSSS | + Expand image

A giant dish with a honeycomb-patterned device at its center is shown in a desert landscape.

This artist's concept shows what Deep Space Station-23, a new antenna dish capable of supporting both radio wave and laser communications, will look like when completed at the Deep Space Network's Goldstone, California, complex. Image credit: NASA/JPL-Caltech | + Expand image

A swirling fabric of glowing neon green, orange, and pink extends above Earth's limb. A partial silhouette of the ISS frames the right corner of the image.

Expedition 52 Flight Engineer Jack Fischer of NASA shared photos and time-lapse video of a glowing green aurora seen from his vantage point 250 miles up, aboard the International Space Station. This aurora photo was taken on June 26, 2017. Image credit: NASA | › Full image and caption

In the News

As March 14 approaches, it’s time to get ready to celebrate Pi Day! It’s the annual holiday that pays tribute to the mathematical constant pi – the number that results from dividing any circle's circumference by its diameter.

Pi Day comes around only once a year, giving us a reason to chow down on our favorite sweet and savory pies while we appreciate the mathematical marvel that helps NASA explore Earth, the solar system, and beyond. There’s no better way to observe this day than by getting students exploring space right along with NASA by doing the math in our Pi Day Challenge. Keep reading to find out how students – and you – can put their math mettle to the test and solve real problems faced by NASA scientists and engineers as they explore the cosmos!

How It Works

Dividing any circle’s circumference by its diameter gives us pi, which is often rounded to 3.14. However, pi is an irrational number, meaning its decimal representation goes on forever and never repeats. Pi has been calculated to 50 trillion digits, but NASA uses far fewer for space exploration.

Some people may think that a circle has no points. In fact, a circle does have points, and knowing what pi is and how to use it is far from pointless. Pi is used for calculating the area and circumference of circular objects and the volume of shapes like spheres and cylinders. So it's useful for everyone from farmers storing crops in silos to manufacturers of water storage tanks to people who want to find the best value when ordering a pizza. At NASA, we use pi to find the best place to touch down on Mars, study the health of Earth's coral reefs, measure the size of a ring of planetary debris light years away, and lots more.

In the United States, one format to write March 14 is 3.14, which is why we celebrate on that date. In 2009, the U.S. House of Representatives passed a resolution officially designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi. And you're in luck, because that's precisely what the NASA Pi Day Challenge is all about.

The Science Behind the 2021 NASA Pi Day Challenge

This year, the NASA Pi Day Challenge offers up four brain-ticklers that will require students to use pi to collect samples from an asteroid, fly a helicopter on Mars for the first time, find efficient ways to talk with distant spacecraft, and study the forces behind Earth's beautiful auroras. Learn more about the science and engineering behind the problems below or click the link below to jump right into the challenge. Be sure to check back on March 15 for the answers to this year’s challenge.

› Take the NASA Pi Day Challenge

› Educators, get the lesson here!

Sample Science

NASA’s OSIRIS-REx mission has flown to an asteroid and collected a sample of surface material to bring back to Earth. (It will arrive back at Earth in 2023.) The mission is designed to help scientists understand how planets form and add to what we know about near-Earth asteroids, like the one visited by OSIRIS-REx, asteroid Bennu. Launched in 2016, OSIRIS-REx began orbiting Bennu in 2018 and successfully performed its maneuver to retrieve a sample on October 20, 2020. In the Sample Science problem, students use pi to determine how much of the spacecraft's sample-collection device needs to make contact with the surface of Bennu to meet mission requirements for success.

Whirling Wonder

Joining the Perseverance rover on Mars is the first helicopter designed to fly on another planet. Named Ingenuity, the helicopter is a technology demonstration, meaning it's a test to see if a similar device could be used for a future Mars mission. To achieve the first powered flight on another planet, Ingenuity must spin its blades at a rapid rate to generate lift in Mars’ thin atmosphere. In Twirly Whirly, students use pi to compare the spin rate of Ingenuity’s blades to those of a typical helicopter on Earth.

Signal Solution

NASA uses radio signals to communicate with spacecraft across the solar system and in interstellar space. As more and more data flows between Earth and these distant spacecraft, NASA needs new technologies to improve how quickly data can be received. One such technology in development is Deep Space Optical Communications, which will use near-infrared light instead of radio waves to transmit data. Near-infrared light, with its higher frequency than radio waves, allows for more data to be transmitted per second. In Signal Solution, students can compare the efficiency of optical communication with radio communication, using pi to crunch the numbers.

Force Field

Earth’s magnetic field extends from within the planet to space, and it serves as a protective shield, blocking charged particles from the Sun. Known as the solar wind, these charged particles of helium and hydrogen race from the Sun at hundreds of miles per second. When they reach Earth, they would bombard our planet and orbiting satellites were it not for the magnetic field. Instead, they are deflected, though some particles become trapped by the field and are directed toward the poles, where they interact with the atmosphere, creating auroras. Knowing how Earth’s magnetic field shifts and how particles interact with the field can help keep satellites in safe orbits. In Force Field, students use pi to calculate how much force a hydrogen atom would experience at different points along Earth’s magnetic field.

Teach It

Pi Day is a fun and engaging way to get students thinking like NASA scientists and engineers. By solving the NASA Pi Day Challenge problems below, reading about other ways NASA uses pi, and doing the related activities, students can see first hand how math is an important part of STEM.

Pi Day Resources

Plus, join the conversation using the hashtag #NASAPiDayChallenge on Facebook, Twitter, and Instagram.

Related Lessons for Educators

Related Activities for Students

TAGS: Pi, Pi Day, NASA Pi Day Challenge, Math, Mars, Perseverance, Ingenuity, Mars Helicopter, OSIRIS-REx, Bennu, Asteroid, Auroras, Earth, Magnetic Field, DSOC, Light Waves, DSN, Deep Space Network, Space Communications

  • Lyle Tavernier
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