NASA can now communicate with its spacecraft using lasers

As more and more missions are sent into outer space and as these missions carry increasingly sophisticated equipment, the amount of data that needs to be sent back to Earth is increasing beyond the capabilities of current radio communication systems.

The solution to this problem is to use higher frequencies, which can carry more data. But before any new communications system can be widely used, it must be thoroughly tested.

That's the goal of a new experimental project called Deep Space Optical (DSOC) Communications, which has been deployed alongside the Psyche mission to the main asteroid belt of the solar system, to test whether lasers can be used to communicate more efficiently. The experiment sent back its first test data last year and earlier this year, and the results were real data from the spacecraft that was successfully beamed back to Earth.

Now, the DSOC project has reached a new milestone by completing its first operational phase, and successfully sending data from a distance of 290 million miles — which is also the maximum distance between Earth and Mars at its farthest point.

' This milestone is significant. Laser communication requires a very high level of precision and before Psyche's launch, we had absolutely no idea how much the transmission performance would degrade at the longest distances, ' said Meera Srinivasan, head of the DSOC project, in a statement. ' Optical communication could be a powerful and transformative method for exploring the solar system .'

Engineers were already confident that laser communications were possible, and they had estimated their accuracy over very long distances. But as with any space technology, it's important to always test that everything works correctly, both in theory and in practice. One of the main challenges for DSOC was ensuring that the antennas on the ground and on the spacecraft could point at each other accurately enough to send data over very long distances.

The team also wanted to test the data rates they could expect using laser communications at different distances. At a distance of 33 million miles, about the same distance as Mars at its closest point to Earth, DSOC achieved a bit rate of 267 megabits per second, similar to broadband internet speeds. At a much farther distance of 240 million miles, the rate was still as high as 6.25 megabits per second. Distance reduces the bit rate significantly, but it's still much faster than what's possible with current radio communications systems.

The first phase of the test is now complete, and the transceiver has been powered down. But the test isn't over yet, and will be restarted next month to test whether the hardware can survive a year in space and continue to function properly.

Lesley Montoya

Update 08 October 2024