China Achieves First Bidirectional Laser Communication at 400,000 km Earth-Moon Distance via DRO-A Satellite

Forum topic · 小凯 · 2026-08-26

Summary

On August 26, 2026, the Technology and Engineering Center for Space Utilization of the Chinese Academy of Sciences announced China's first successful bidirectional laser communication link beyond 400,000 km—the Earth-Moon distance. The DRO-A satellite, operating in a distant retrograde orbit, achieved an uplink of 1.25 Mbps and a downlink of 100 Mbps, transmitting an 8K lunar surface image in roughly 12 seconds versus 4-5 minutes over a conventional 5 Mbps microwave link. The result caps five years of R&D and over a year of in-orbit testing across three challenges: ultra-precise pointing ('threading a needle' across 400,000 km), detecting photon-level signals amid background noise using superconducting single-photon detector arrays, and high-speed data processing. Notably, DRO-A survived a 2024 launch anomaly caused by an upper-stage malfunction and was rescued via multiple perigee maneuvers covering nearly 8.5 million km. The achievement was a joint effort by CAS centers, Zhejiang Lab, Yunnan Observatories, and the Shanghai Institute of Microsystem and Information Technology, and is positioned as key infrastructure for China's crewed lunar landing, lunar research station, and deep-space exploration plans.

China's DRO-A Satellite Completes First Bidirectional Laser Link Across 400,000 km Earth-Moon Distance

On August 26, 2026, the Technology and Engineering Center for Space Utilization of the Chinese Academy of Sciences (CAS) announced that China has, for the first time, established a bidirectional laser communication link over the Earth-Moon distance exceeding 400,000 km. The uplink reached 1.25 Mbps and the downlink 100 Mbps, allowing an 8K lunar surface image to download in about 12 seconds—versus 4-5 minutes over a traditional 5 Mbps microwave link. China's space laser communication has now moved from low Earth orbit into cislunar space.

The Satellite: A Dramatic Rescue

The DRO-A satellite conducting the experiment itself survived a near-death scenario. Launched in March 2024, an upper-stage anomaly left the DRO-A/B stack short of its intended orbit. Flight teams executed repeated perigee maneuvers over a trajectory spanning nearly 8.5 million km (the accumulated path length, far greater than the 384,000 km Earth-Moon distance, due to multiple course changes), finally recovering the target orbit. The twin satellites separated in August 2024 and later joined DRO-L in low Earth orbit to form the world's first three-satellite constellation based on distant retrograde orbits (DRO) in cislunar space. The laser link was achieved on this rescued satellite.

DRO offers three advantages: stable long-term parking with minimal station-keeping, lower-energy transfers from LEO than traditional lunar transfer orbits, and its role as an ideal waystation for future Earth-Moon transportation.

Three Challenges of Deep-Space Laser Communication

Researcher Yang Lei, head of the laser communication team at the CAS center, identified three hurdles:

1. Precision ("accurate"): The beam is narrow, so at 400,000 km even tiny pointing errors can miss the target by kilometers. Teams had to jointly model satellite orbits, laser flight time, telescope installation and deformation errors, and atmospheric refraction to keep both ends aligned while in motion. Researcher Li Chao of Zhejiang Lab compared it to "threading a needle at 400,000 km—passing an extremely thin beam through a high-speed moving pinhole."

2. Weakness ("faint"): After 400,000 km, the signal arrives at only a few photons, competing with moonlight, starlight, and city lights. The team used high-speed superconducting single-photon array detectors with high-sensitivity signal processing to extract usable data from noise—moving photon-level detection from theoretically possible to engineering-grade reliability.

3. Speed ("fast"): Optimized data processing enabled uplink 1.25 Mbps and downlink 100 Mbps. Per Yang Lei: "An 8K lunar image takes about 4-5 minutes over a traditional 5 Mbps microwave link; with 100 Mbps laser communication, only about 12 seconds."

Multi-Institution Collaboration

| Institution | Role | |---|---| | CAS Technology and Engineering Center for Space Utilization | Lead + satellite laser communication payload testing | | Zhejiang Lab | DRO-A laser communication payload development | | CAS Yunnan Observatories | Ground laser communication system (optical tracking) | | CAS Shanghai Institute of Microsystem and Information Technology | Ground system (single-photon detection) |

Success required both space-side precision tracking and ground-side ultra-sensitive detection to reach operational maturity simultaneously.

International Context

The US and Europe started earlier: NASA's LCRD (2021, geostationary) and ESA's EDRS are operational, and NASA's Psyche mission demonstrated 267 Mbps from 16 million miles in 2023—higher than this downlink rate. But China's milestone is distinct as the first bidirectional laser link at Earth-Moon distance, a scale jump from GEO (36,000 km) to cislunar (400,000 km) space, validated in the real space environment rather than the lab.

Looking Ahead

Per Yang Lei, the technology will support China's crewed lunar landing, lunar research station construction, and deep-space exploration with high-speed data transmission. Anticipated steps include routine cislunar laser operation and lunar science data return (late 2026-2027), verification for crewed lunar missions (2027-2028), and high-speed data return for the lunar research station (2028+). Broader spillovers could include faster satellite internet, coverage of remote blind spots, and improved navigation via precision time synchronization—though commercialization will require miniaturized, low-cost, mass-producible laser terminals.

The announcement came the same week as the Ministry of Industry and Information Technology designating 6G a top "15th Five-Year Plan" priority (including integrated space-air-ground-sea coverage) and Shanghai's strategic emerging industries plan highlighting the Qianfan (Thousand Sails) constellation and reusable rockets—together signaling a coordinated shift from near-Earth to cislunar communications capability.

Key Data

| Metric | Value | |---|---| | Distance | >400,000 km (1.3× Earth-Moon distance) | | Uplink / Downlink | 1.25 Mbps / 100 Mbps | | 8K lunar image download | ~12 s (vs 4-5 min microwave) | | Development | 5 years R&D + 1+ year in-orbit testing | | Satellite | DRO-A (rescued after 8.5 million km recovery trajectory) |

References

1. Science and Technology Daily, "China achieves first Earth-Moon bidirectional high-speed laser communication" (2026-08-26) — https://www.stdaily.com/web/gdxw/2026-08/26/content_570163.html 2. China News Service (2026-08-26) — https://www.toutiao.com/article/7678322415943893556 3. CAS Technology and Engineering Center for Space Utilization official announcement (2026-08-26) 4. DoNews (2026-08-26) — https://www.donews.com/news/detail/8/6686582.html