NASA’s Jet Propulsion Laboratory (JPL) has announced a new record set by the Psyche mission. It successfully sent a laser signal to Earth from a distance of 350 million kilometers. That’s more than the distance between our planet and Mars.
The Psyche mission was launched in 2023 with the aim of studying Psyche, a 220-kilometer metal asteroid that, according to one hypothesis, may be a fragment of the core of a dead protoplanet. The spacecraft is scheduled to reach it in 2029.
In addition to studying the asteroid, Psyche also has the function of a “tester.” NASA specialists installed an experimental optical communication system on board. Its main advantage over traditional radio communication is its much higher (10 to 100 times) data transfer rate. Lasers can transmit complex scientific information, as well as high-definition images and videos. This is especially important for the next stage of space exploration, when humans will travel to the Moon and Mars and will need to quickly send large amounts of data back to Earth.
The first experiment took place on December 11, 2023, when Psyche was 31 million kilometers from Earth. The spacecraft sent a 15-second video of a cat to Earth (it was preloaded before launch). The data transfer rate was 267 Mbit/s. This is a couple of orders of magnitude faster than when using radio communication.
JPL specialists repeated the experiment several times in the future. As Psyche moved away from Earth, the data transfer rate gradually decreased (for example, when the spacecraft was 226 million km away, it was 25 Mbit/s), but it was still much faster than traditional radio communications. In addition, engineers tested another innovation in the form of duplicate data. The spacecraft successfully demonstrated that it can simultaneously use both radio and laser communication systems to communicate with Earth. The radio data was transmitted to NASA’s Deep Space Network, and the laser data was received by the Hale telescope at Palomar Observatory. The photons captured by it were then directed to a highly efficient detector array, where the information encoded in them was processed.
Almost two years after the start, JPL specialists conducted the 65th and final experiment. During the mission, Psyche once again broke the distance record by successfully sending a signal from a distance of 350 million km. This corresponds to the radius of the inner boundary of the asteroid belt.
According to scientists, the experiments successfully demonstrated the effectiveness of the technology. Data encoded by lasers can be reliably transmitted, received, and decoded after passing hundreds of millions of kilometers. In total, Psyche transmitted 13.6 terabits of data to Earth over the entire period. At the same time, the data transfer rate turned out to be even higher than expected. All this means that the technology has great prospects, especially when space agencies face the challenge of transmitting large amounts of high-resolution images and data from the Moon and Mars.
According to JPL
