In deep space, sending data across millions of miles isn’t fast or easy. Right now, spacecraft mostly use radio waves to communicate with Earth.
But NASA just pulled off something that could change the way future astronauts transmit data from as far away as Mars. They used a laser to send high-speed data across deep space – and it worked.
Lasers join the space race
Two years ago, NASA launched a mission called Psyche. Along for the ride was an experiment called Deep Space Optical Communications, or DSOC.
Its goal? To test if lasers could be used instead of radio waves for long-distance space communication.
It’s now a done deal. Over the course of 65 test sessions, DSOC proved that laser-based data transmission works – and works well – even from hundreds of millions of miles away.
NASA completed its final laser test when Psyche was 218 million miles from Earth – nearly the average distance between Earth and Mars.
The laser beam traveled through space, was received by the spacecraft’s equipment, and then beamed back to Earth. Everything worked exactly as it should.
Space lasers prove their speed
Just one month after launch, the technology showed it could make a link between Earth and Psyche using laser light.
“NASA technology tests hardware in the harsh environment of space to understand its limits and prove its capabilities,” said Clayton Turner, associate administrator at NASA’s Space Technology Mission Directorate.
“Over two years, this technology surpassed our expectations, demonstrating data rates comparable to those of household broadband internet and sending engineering and test data to Earth from record-breaking distances.”
That wasn’t just talk. On December 11, 2023, the system sent an ultra-high-definition video from 19 million miles away. It streamed at 267 megabits per second – that’s faster than many home internet plans.
On December 3, 2024, it successfully downlinked data from a staggering 307 million miles away. Altogether, NASA received 13.6 terabits of data from Psyche using lasers alone.
Precision aiming across the cosmos
DSOC’s setup included a space laser device onboard the Psyche spacecraft, a powerful 3-kilowatt laser uplink on Earth, and two main ground stations.
The uplink laser came from NASA’s Table Mountain Facility in California. It pointed a beacon at Psyche to help the spacecraft aim its laser signal back to Earth.
This wasn’t just point-and-shoot. Earth and Psyche are both moving fast through space, and the distance between them means even light takes several minutes to travel.
Getting the timing and direction right was a major challenge. But they pulled it off.
The returning laser signal was incredibly faint. To catch it, NASA used a 200-inch telescope at Caltech’s Palomar Observatory.
The telescope’s large light-collecting area helped capture enough of the signal – just a few particles of light, or photons – to decode the data.
Big wins, even with setbacks
Like any long-term experiment, this one faced bumps in the road. There was weather events that shuttered ground operations and wildfires in Southern California impacted scientists.
“But we persevered, and I am proud that our team embraced the weekly routine of optically transmitting and receiving data from Psyche,” said Abi Biswas, the project’s technologist and supervisor at JPL.
“We constantly improved performance and added capabilities to get used to this novel kind of deep space communication, stretching the technology to its limits.”
Smarter antennas talking across space
NASA also tested new ways to receive the signals. In one case, they transmitted data to a hybrid antenna in California that could detect both radio and laser signals.
This setup included seven mirrors arranged in a three-foot-wide array to collect laser light.
They also used a technique called “arraying,” where multiple telescopes – like the ones at Palomar Observatory and Table Mountain – received the same signal.
This is often done with radio waves to improve signal strength, and now NASA showed it works with lasers too.
“As space exploration continues to evolve, so do our data transfer needs,” said Kevin Coggins, deputy associate administrator of NASA’s SCaN program.
“Future space missions will require astronauts to send high-resolution images and instrument data from the Moon and Mars back to Earth. Bolstering our capabilities of traditional radio frequency communications with the power and benefits of optical communications will allow NASA to meet these new requirements.”
Looking ahead to Mars
“NASA is setting America on the path to Mars, and advancing laser communications technologies brings us one step closer to streaming high-definition video and delivering valuable data from the Martian surface faster than ever before,” said acting NASA Administrator Sean Duffy.
“Technology unlocks discovery, and we are committed to testing and proving the capabilities needed to enable the Golden Age of exploration.”
For future astronauts on Mars, this kind of tech could be life-changing. It means faster, clearer, and more reliable contact with home – whether that’s streaming HD footage of the Martian surface or sending back vital data from science experiments.
Laser communication might seem like science fiction. But it’s not. NASA just proved it works.
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