NASA once again tests deep space optical communication over a distance of 226 million kilometers, transmitting data at a rate of 25Mbps

In October 2023, Space Exploration Technology Corporation (SpaceX) passedFalcon 9 Heavy launch vehicle launches NASA's Psyche probe into orbitthis probe is mainly used to explore 16 Psyche, a metallic asteroid in the solar system.

The detector is also equipped with a deep space optical communication module (DSOC). The main purpose is to try to use lasers instead of radios to transmit data. The reason is that the bandwidth of radio for deep space transmission is limited and it takes too long to transmit a large amount of data. .

The DSOC module has been tested in December 2023. At that time, the Psyche probe was 32 million kilometers away from the earth.At that time, the test achieved a transmission rate of 267Mbpsabout 33MB/s, this speed is already very high.

On April 8, when the Ling Shen probe was about 226 million kilometers away from the earth, NASA launched the DSOC deep space optical communication test again. The average rate of this test reached 25Mbps. Engineers at JPL Jet Propulsion Laboratory spent about 10 minutes downloading Ling Shen. The repeated engineering data of the Shenxing probe are tested.

Although the speed of this test is much lower than before, the detector is now farther away, and NASA originally considered a speed of only 1Mbps, so 25Mbps is still a huge success.

Both radio and laser propagate at the speed of light. The difference is that radio is more resistant to interference. Laser can carry more data, but it can only successfully establish a link under clear weather conditions. Radio has almost no such limitation. .

Therefore, NASA will use radio and laser links in the future. When it needs to transmit a large amount of scientific data, it will wait for good weather to use laser communication, and continue to use wireless wires when sending commands at ordinary times, which will be more reliable.