How Do We Communicate with Faraway Spacecraft?
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 radio antennas used to communicate with spacecraft at the Moon and beyond. Operators at the Deep Space Network take commands, break them into digital bits, precisely aim these big antennas at the spacecraft, and send the commands to the spacecraft using radio waves.
The antennas of NASA’s Deep Space Network are the indispensable link to robotic explorers venturing beyond Earth. They provide the crucial connection for commanding our spacecraft and receiving their never-before-seen images and scientific information on Earth, propelling our understanding of the universe, our solar system and ultimately, our place within it. Managed by NASA’s Jet Propulsion Laboratory for the Space Communications and Navigation (SCaN) Program, based at NASA Headquarters within the Space Operations Mission Directorate, the Deep Space Network is what enables missions to track, send commands to, and receive scientific data from faraway spacecraft.
Learn more about the DSN at go.nasa.gov/about-dsn
About the 70-Meter Antenna
Each Deep Space Network, or DSN, site has one huge, 70-meter (230-foot) diameter antenna. The 70-meter antennas are the largest and most sensitive DSN antennas, capable of tracking a spacecraft traveling tens of billions of miles (kilometers) from Earth.
Weighing in at nearly 2,970 U.S. tons (2.7 million kilograms), the surface of this giant, dish-shaped reflector is maintained to a precision of within half an inch (one centimeter) across its entire 41,400 square foot (3,850-square-meter) surface. This precision is crucial – even minor deformations would interfere with the antenna’s operations.
NASA built the 70-meter antenna when ambitious missions began venturing beyond Earth orbit and needed more powerful communications tools to track them. The 70-meter antenna in Goldstone, dubbed the “Mars antenna,” was the first of the giant antennas designed to receive weak signals and transmit very strong ones far out into space, featuring a 64-meter-wide (210-foot) dish when it became operational in 1966. The dish was upgraded from 64 meters to 70 meters in 1988 to enable the antenna to track NASA’s Voyager 2 spacecraft as it encountered Neptune.
The Mars antenna has supported missions that include Pioneer, Cassini and the Mars Exploration Rovers. It received Neil Armstrong’s famous communiqué from Apollo 11: “That’s one small step for a man. One giant leap for mankind.” It has also helped with imaging nearby planets, asteroids and comets by bouncing its powerful radar signal off the objects of study.
NASA In Your Neighborhood – NASA’s Parker Solar Probe : Humanity’s First Mission to a Star
Virtual presentation with Dr. Phyllis L. Whittlesey, PhD Research Scientist : Deputy Associate Director, Solar and Heliophysics, Space Sciences Lab – University of California, Berkeley
Each of the three Deep Space Network, or DSN, sites has multiple large antennas and is designed to enable continuous radio communication between several spacecraft and Earth. All three complexes consist of at least four antenna stations, each equipped with large, parabolic dish antennas and ultra-sensitive receiving systems capable of detecting incredibly faint radio signals from distant spacecraft.
The DSN’s large antennas are focusing mechanisms that concentrate power when receiving data and when transmitting commands. The antennas must point very accurately towards the spacecraft, because an antenna can “see” only a tiny portion of the sky – not unlike looking at the sky through a soda straw.
To hear the spacecraft’s faint signal, the antennas are equipped with amplifiers, but there are two problems. First, the signal becomes degraded by background radio noise, or static, emitted naturally by nearly all objects in the universe, including the sun and earth. The background noise gets amplified along with the signal. Second, the powerful electronic equipment amplifying the signal adds noise of its own. The DSN uses highly sophisticated technology, including cooling the amplifiers to a few degrees above absolute zero, and special techniques to encode signals so the receiving system can distinguish the signal from the unwanted noise.
Antenna stations are remotely operated from a signal processing center at each complex. The centers house electronic systems that point and control the antennas, receive and process data, transmit commands and generate spacecraft navigation data.
Once the data is processed at the complexes, it is transmitted to NASA’s Jet Propulsion Laboratory for further processing and distribution to science teams over a ground communications network.
The Australian complex is located 40 kilometers (25 miles) southwest of Canberra near the Tidbinbilla Nature Reserve. The Spanish complex is located 60 kilometers (37 miles) west of Madrid at Robledo de Chavela. The Goldstone complex is located on the U.S. Army’s Fort Irwin Military Reservation, approximately 72 kilometers (45 miles) northeast of the desert city of Barstow, California. Each complex is situated in semi-mountainous, bowl-shaped terrains to shield against external radio frequency interference.
NASA has robotic explorers all over our solar system – and beyond! How do we communicate with these faraway spacecraft? With the big antennas of the Deep Space Network, or DSN! The DSN has three antenna complexes evenly spaced around the world in the United States, Spain, and Australia. Watch this virtual tour of each complex to learn more about each one!
Lance Benner – DSN Earth Day Presentation
Celebrate Earth Day April 22, 2020
By hearing from Dr. Lance Benner about how NASA uses Goldstone System Radar imaging of near-Earth asteroids to protect Earth. Dr. Benner is an astronomer at NASA’s Jet Propulsion Laboratory. He has an A.B. in Physics, Cornell University and a Ph. D. in Earth and Planetary Sciences, Washington University.
Chuck Scott – Mars 2020 Presentation
July 15, 2020
Join us as we explore the red planet with Mr. Charles “Chuck” Scott.
The Mars 2020 mission with its Perseverance rover is part of NASA’s Mars Exploration Program, a long-term effort of robotic exploration of the Red Planet. The Mars 2020 mission addresses high-priority science goals for Mars exploration, including key Astrobiology questions about the potential for life on Mars.
A Day in the Life of the Deep Space Network with Dr. Joe Lazio
Following a day in the life of the Deep Space Network; the coder to the scientist to the ACE to the spacecraft and back again. We’ll explore the different aspects of what actually goes into the difficult Tetris game that is Deep Space Communications and what’s coming next.