NASA can now communicate with its spacecraft using lasers.
The NASA Optical Communications in Deep Space test has completed its first phase, demonstrating that laser communications in space are viable and faster than radio communications.
NASA is facing a challenge in its communications: the radio frequencies used by spacecraft are becoming increasingly saturated. With the increase in space missions and the incorporation of more sophisticated instruments, the amount of data that needs to be transmitted to Earth is exceeding the capacity of current radio communication systems. The proposed solution involves implementing higher frequencies that can handle larger volumes of data. However, before a new communication system is widely adopted, it is essential to conduct tests.
A clear example of this is the Deep Space Optical Communications (DSOC) experiment, which is traveling with the Psyche mission to the asteroid belt of the solar system to assess the feasibility of using lasers for more efficient communications. This experiment began sending test data last year, and at the beginning of this year, it successfully transmitted real data from the spacecraft. Recently, DSOC achieved a new milestone by completing the first phase of operations, sending data from a distance of 290 million miles, which corresponds to the maximum distance between Earth and Mars when they are at their farthest point.
Meera Srinivasan, the DSOC operations lead, noted that this achievement is significant because laser communication requires a high level of precision. Before the Psyche mission, there was uncertainty about the degree of performance degradation at great distances. The tracking and alignment techniques used have proven effective, confirming that optical communications can represent a robust and transformative approach to solar system exploration.
Prior to the launch of DSOC, engineers were confident in the feasibility of laser communications and had made estimates about the expected precision over long distances, although it is always crucial to validate that systems operate correctly under real conditions. One of the main challenges was ensuring that the ground and spacecraft antennas could accurately align with each other, enabling data transmission over long distances.
Additionally, the team sought to determine the expected data rates with laser communications from different distances. At 33 million miles, which is equivalent to the minimum distance between Mars and Earth, DSOC achieved a bit rate of 267 megabits per second, similar to broadband internet speeds. At a significantly greater distance of 240 million miles, it still managed to maintain 6.25 megabits per second, a remarkably higher figure compared to existing radio communication systems.
Once this first phase of testing was completed, the transceiver was turned off, but the experiment is not over. The system is expected to be reactivated next month to verify that the hardware can withstand a full year in space and continue to function properly. Ken Andrews, the project’s flight operations lead, indicated that after turning the flight laser transceiver back on, a brief functionality review will be conducted, which will pave the way to operate the transceiver at its maximum design capacity during the post-conjunction phase that will begin later in the year.
