Ever wonder how spacecraft stay in touch without a smartphone?
If you’ve ever seen Apollo 13, then you know how critical it is for a spacecraft to hang on to its line of communication if Mission Control hears “Houston, we have a problem.” When the spacecraft lost contact with NASA’s Manned Space Flight Network because battery power was running low and the astronauts were unable to use the high-gain antennas, Space.com reminds us it was NASA’s Deep Space Network (DSN) that joined forces with the Parkes Observatory radio telescope to bring the stranded module back to Earth.
The DSN is a radio telescope array that uses parabolic dish antennas to talk to 33 spacecraft (not all of them NASA) floating around the solar system. You can even see what it’s up to right now. Its three facilities are Goldstone in the remote signal-distraction-free expanse of the Mojave Desert, the Madrid Deep Space Communications Complex (MDSCC) in Spain, and the Canberra Deep Space Communication Complex (CDSCC) in Australia, which tracked the Apollo Lunar Module when it was dangerously close to getting lost in space.
Human eyes saw their first glimpses of distant planets because of the DSN. It beamed back the first image of Mars ever to reach terra firma back in 1965 via the NASA Mariner 4 spacecraft, and images of Mercury’s surface followed in 1974.
Then there was Voyager. It was the DSN that allowed Earthlings to see the first closeups of Jupiter, Saturn, Neptune, and Uranus, along with some of their rings and moons from Voyager 1 and 2 flybys. You know Carl Sagan’s iconic “pale blue dot”? That snapshot of our planet taken from 6 billion miles away was sent here by the DSN.
As if the DSN isn’t already a multitasking wizard, it also does science. It was the DSN that used Cassini’s final signals to figure out the mass of the mysterious B-ring, something that eluded astronomers for years, before the satellite took its kamikaze plunge into Saturn. It can tell any spacecraft its distance from Earth based on satellite signals, observe radio sources like pulsars and quasars, and study radar by bouncing waves off asteroids that whiz by.
DSN also makes sure any scientific data gathered by spacecraft lands on the home planet. When Galileo suffered a broken antenna as it was orbiting Jupiter, it was still possible to save its findings by arraying international DSN stations.
"If it wasn't for the DSN, there wouldn't be any science, because nobody could listen to [the spacecraft]," Sue Finley, a subsystem engineer who worked on the Galileo mission, told Space.com.
One more thing—DSN also transmitted images of the first moonwalk to TVs on Earth. Now you know how everyone found out about that one small step for man.