By measuring radio signals transmitted to and received from distant spacecraft, NASA's Deep Space Network can determine a spacecraft's position and speed and send commands to alter its trajectory.

The Deep Space Network is an array of giant radio antennas at three locations on Earth to keep NASA in constant communication with spacecraft billions of miles away.

Deep Space Network sites enable nonstop communication with distant spacecraft

Each DSN complex has multiple large, sensitive antennas that can receive weak radio signals from far-off spacecraft and send commands back to them. Their amplifiers are cooled to just above absolute zero to reduce electronic noise.

Voyager science teams still collect valuable space data using four active tools

These instruments track magnetic fields, solar wind particles, radio emissions from the heliopause, and hydrogen levels in the outer heliosphere. Even though each Voyager sends data at just 160 bits per second, NASA receives 6–8 hours of tracking data daily.

GPS satellites are programmed to account for their faster passage of time in space

The Global Positioning System relies on signals from satellites to calculate locations on Earth by measuring time and distance. However, their orbits, being farther from Earth's center, cause them to experience less gravitational time dilation. These systems would be off by 11 kilometers per day without relativistic corrections.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

Astronomers use a set of scaffolding methods to measure distances across the universe

Different methods are used depending on how far away an object is—from radar for nearby planets, to parallax for stars, to redshift and supernovae for distant galaxies. These tools allow scientists to chart the universe across unimaginable scales using astronomical units (AU), light-years, and parsecs.

When GPS and sonar are unavailable, submarine navigation relies on a fiber-optic gyroscope to determine the vessel's orientation and an accelerometer to calculate distance traveled.

Sonar, or sound navigation and ranging, uses reflected sound waves to map and detect seafloor features, marine organisms, and other obstacles.

By analyzing the color of starlight, astronomers can determine how fast stars within a galaxy are moving toward or away from Earth, revealing the expansion rate of the universe.

Scientists can map Earth's shape and structure by measuring the ratios of certain particles arriving from different directions in space, as these ratios change with the density of the material particles travel through.

Because seismic waves travel 100 times faster than tsunami waves—waves typically travel faster through solids than liquids—measurements of geological activity help tsunami detection systems provide early warnings.

The accidental birth of radio astronomy and the benefits of a moon-based telescope

Detecting radio waves from distant celestial objects is complicated by noise from solar wind, which the nighttime side of the moon is shielded from. If lunar temperature extremes can be overcome, the environment may serve as an optimal future home for radio astronomy, a field that began in 1928 when a 30-meter-long directional antenna, mostly out of brass and wood, picked up signals from the Sagittarius constellation.

What does NASA do besides space?

Although its splashiest accomplishments are the ones taking place in outer space, NASA actually does a lot more than space exploration. The federal administration also conducts intensive research on the interconnected systems of the Earth, from studies of the atmosphere and oceans to research into the composition of the planet's interior. See what NASA is discovering about our home planet here.

Simulate how the distribution of dark matter affects stellar orbits within galaxies, which allows astronomers to infer the presence of the invisible substance from the motion of stars.

NASA was founded in response to early Soviet space achievements

Although starting behind in the Space Race in 1958, NASA became a global leader in humanity's exploration of space with the Apollo program, which placed astronauts on the moon. Since then, it has been responsible for the construction of multiple telescopes, the International Space Station, and development of the Artemis program to return humans to the Moon before eventually reaching Mars.

NASA's DART mission successfully deflected an asteroid

The Double Asteroid Redirection Test crashed into asteroid moonlet Dimorphos in 2022, altering its orbital radius. The project required precise astrodynamics to strike the moonlet from 11 million kilometers away while traveling 22,530 kilometers per hour.

Explore a series of NASA visualizations tracking satellites and space debris

The series illustrates the population of objects orbiting Earth as of February 2024, using data from US Space Command. These include active satellites, defunct spacecraft, rocket bodies and debris fragments larger than roughly 10 centimeters in low Earth orbit.

How radio works

Antennae tune a radio to a particular frequency (determined by the listener on their radio's dial) while tuning out all the other stations being broadcast. AM, short for amplitude modulation, and FM, short for frequency modulation, decode audio signals differently, leading to differences in sound quality and the distance a station can travel.

Watch a visualization of what it would look like to move along Earth's surface as fast as the International Space Station, or about 23 times the speed of sound.

Listen to the sounds of pulsars, which emit radio pulses up to hundreds of times a second

Just as figure skaters spin faster by tucking in their arms, these celestial objects acquire high rates of spin from the collapse of the cores of massive stars. The star's rotation spins its magnetic field, generating beams of radio waves from its magnetic poles. If either of these poles faces a detector, the signals can be picked up and converted to audio signals.

Excluding using another planet's gravity to redirect the object, it takes less energy for a spacecraft to leave the solar system than to hit the sun.

By 2028, a space trash-avoiding maneuver is expected to occur every 18 seconds

As the number of active Starlink satellites increases, greater efforts will be required to keep low Earth orbit free of debris, sparking a new technological space race. NASA has found that using lasers to manage small and medium debris could save up to $9B over 30 years.

Space probes propelled by lasers may one day visit distant planetary systems

Launched in 2016, Breakthrough Starshot is a project to send gram-sized spacecraft to the nearest stars and their planets at 10% to 20% the speed of light after being accelerated by ground-based laser systems. The project requires orders of magnitude advancements to current technology.

Gravity assists are crucial for space travel beyond Mars

By traveling near a moving celestial object, a passing object can gain or lose speed and change direction due to the acceleration provided by their mutual gravity. Some missions are planned around spacecraft performing multiple assists, or slingshots, to reduce fuel requirements for long-distance travel.

Radio waves are used in broadcasting, weather radar, telecommunications, and GPS

Its ability to bend around obstacles and reflect off the ionosphere—an electrified layer of Earth's upper atmosphere—allows this type of light to travel long distances without damaging living things due to its low energy. MRI scanners, WiFi, and Bluetooth technologies are also applications of this form of light.

Satellites in low Earth orbit can experience changes in their orbits due to shifts in solar activity, which alter the amount of energy Earth's atmosphere receives and its resulting density.

Explore how far you've traveled through space while living on Earth

Using the "Cosmic Odometer," users can enter their birthday and learn how far they have moved through space due to the combined effects of Earth's rotation around its axis, the planet's orbit around the sun, the solar system's trajectory through the Milky Way, and the galaxy's motion through the universe.

The history of helioseismology, which studies seismic waves traveling within the sun

Following World War II, scientists began studying the sun's influence on radio waves, the most popular form of mass communication at the time. NASA missions to study the sun's interior have since helped develop explanations for various phenomena in its atmosphere and protect digital infrastructure.

Defending Earth against asteroids

This three-minute video overview explains NASA's ambitious test to slightly alter the course of an asteroid by slamming a fast-moving space probe into its surface. Scientists hope to one day, if needed, use the technique to protect Earth from an asteroid impact.

NASA explores Earth's deepest oceans to prepare for space

By studying extreme environments in Earth's hadal zone—the deepest part of the ocean —NASA tests technologies, probes life under crushing pressure, and gathers clues about potential oceans and possible life on worlds like Europa and Enceladus.

Intended to last four years, the Voyager spacecraft have lasted nearly five decades

Launched in 1977, the Voyager probes still send data from billions of miles away, guided by engineers who’ve turned down promotions to stay with the mission. The team continues to support the probes as they move 37,000 mph through space.

A real-time 3D-explorer of the solar system

NASA's Eyes on the Solar System allows you to track all kinds of objects in space in real time, from observatories like the James Webb Telescope to all manner of comets and asteroids. Zoom in and out, read up on space missions, and see the solar system from a totally new angle with this incredible interactive site. Jump in here.

NASA's Near-Earth Object Surveyor can detect asteroids coming from the sun

Telescopes directed at the sun or lacking heat shields may become damaged, limiting our ability to monitor potentially dangerous objects coming from that direction. The NEO Surveyor is built to overcome this problem and spot asteroids that reflect as little as 5% of incoming light.

Scientists determine the smells of objects in outer space

Using spectrographic techniques, scientists determine the chemical composition of planetary atmospheres, comets, and other objects in space. Combining these chemicals in labs on Earth has revealed locations in space that smell like nail polish remover, rotten fish, and urine.

View 60 years of NASA space exploration

Established in 1958—a year after the Soviet Union launched Sputnik 1—the National Aeronautics and Space Administration has taken humanity into outer space and helped reveal the nature of the universe. Historic moments include the Apollo 11 mission putting humanity on the Moon and construction of the International Space Station.

Space trash is making low Earth orbit increasingly dangerous for spacecraft

Millions of fragments from satellites, rockets, and other spacecraft that are no longer operational move thousands of meters per second as they circle Earth. Even a piece of debris a centimeter in size can cause mission-ending damage to space stations, telescopes, and astronauts.

NASA uses extreme Earth environments to prepare for space exploration

Analog missions in volcanic terrains and craters mimic Martian and lunar environments. Crew members operating in these missions, including at sites in Utah, Nevada, Arizona, and Hawai'i, test suits and specialized space instruments under simulated conditions.