Eventually, we'll want to expand the World Wide Web across the galaxy, and NASA recently demonstrated key technology that could help with that. The space agency transmitted messages via laser at a distance of almost 16 million kilometers, Science alert reported.
That's about 40 times farther than the Moon is from Earth. The achievement, achieved in November 2023, represents the first time optical communications have been sent over such a distance.
We traditionally use radio waves to talk to distant spacecraft - but higher frequencies of light, such as near-infrared, offer increased bandwidth and therefore huge increases in data rates.
If we eventually want to be able to send high-definition video messages to and from Mars without significant lag, this is a step toward the technology we need.
The test is part of NASA's Deep Space Optical Communications (DSOC) experiment, and the successful establishment of a communication link is known as a "first light."
"Achieving first light is one of many critical DSOC milestones in the coming months that paves the way for higher-data-rate communications capable of sending scientific information, high-resolution images and streaming video in support of the next humanity's giant leap," said Trudy Cortes, director of the Technology Demonstration Division at NASA Headquarters.
We all rely on similar technology, embedded in optical fibers, for our terrestrial high-speed communications, but in a NASA experiment it has been adapted for use in deep space to improve existing methods of transmitting information back to Earth.
Since it is infrared light, engineers can easily transmit its waves in the form of a laser. This won't allow the light to travel faster, but it does line up the beam and confine it to a narrow channel. This requires much less energy than broadcasting radio waves and is more difficult to intercept.
This does not mean that the task is simple. Bits of data are encoded in the photons emitted by the laser, which requires a number of heavy-duty instruments—including a superconducting high-efficiency detector array—to prepare the information for transmission and translate it to the other end.
Another challenge is for the system to adapt its configuration for real-time positioning. In this latest test, laser photons traveled from the spacecraft to the telescope in about 50 seconds, with both instruments moving through space during the process.
The laser transceiver that made the connection is aboard the Psyche spacecraft, which is on a multi-year mission to the asteroid belt between Mars and Jupiter. He made contact with the Hale Telescope at the Palomar Observatory in California.
Psyche is scheduled to fly by Mars, so tests will continue to refine and improve this innovative near-infrared laser communication method to ensure it is as fast and reliable as it needs to be.
"It was a huge challenge and we still have a lot of work to do, but in a short time we were able to transmit, receive and decode some data," said Meera Srinivasan, DSOC operations manager at NASA's Jet Propulsion Laboratory. | BGNES
