NASA has successfully transmitted a laser message from nearly 16 million kilometers (10 million miles) away—about 40 times the distance between Earth and the Moon.
The message, sent in November 2023, marks the first time laser communication has been used over such a long distance.
Moving Beyond Radio Waves
Traditionally, radio waves have been used to communicate with distant spacecraft.
However, using higher frequencies of light, like near-infrared, can make data transfer much faster. This is crucial for future missions, where we might need to send high-quality video and other information back and forth between Earth and places like Mars.
This test was part of NASA's Deep Space Optical Communications (DSOC) project. The successful transmission, known as 'first light,' is a key step in developing this new technology.
"Achieving first light is one of many critical DSOC milestones in the coming months, paving the way toward higher-data-rate communications capable of sending scientific information, high-definition imagery, and streaming video in support of humanity's next giant leap," said Trudy Kortes, director of Technology Demonstrations at NASA Headquarters.
Why It Matters
On Earth, we use similar technology in optical fibers for high-speed internet. NASA adapted this for space, using infrared lasers to send the message. This method is more focused and efficient than radio waves, requiring less power and making it harder for the signal to be intercepted.
However, sending data with lasers isn’t easy.
The process involves encoding data into laser photons, which requires special equipment to send and decode the information. The system also has to adjust its aim in real-time because both the spacecraft and the receiving telescope are in motion.
In this test, it took about 50 seconds for the laser photons to travel from the Psyche spacecraft to the Hale Telescope in California. Psyche, which is on its way to the asteroid belt between Mars and Jupiter, will continue to help test and improve this communication method.
NASA’s success with this laser communication marks a significant step toward faster and more reliable space communication.
"It was a formidable challenge, and we have a lot more work to do, but for a short time, we were able to transmit, receive, and decode some data," said Meera Srinivasan, DSOC operations lead at NASA's Jet Propulsion Laboratory.
