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 the first successful bidirectional laser communication link over an Earth-Moon distance exceeding 400,000 km. The experiment, carried on the DRO-A satellite operating in a distant retrograde orbit (DRO), achieved an uplink of 1.25 Mbps and a downlink of 100 Mbps, allowing an 8K high-resolution lunar surface image to be transmitted in about 12 seconds versus 4-5 minutes over a traditional 5 Mbps microwave link. The team overcame three core challenges: precision pointing across 400,000 km, detecting few-photon signals against background noise, and high-speed data processing. Notably, the DRO-A satellite was rescued to its target orbit after an upper-stage anomaly in March 2024 required an 8.5-million-km recovery trajectory. The payload was jointly developed by the CAS center and Zhejiang Lab, with ground stations from CAS Yunnan Observatories and the Shanghai Institute of Microsystem and Information Technology. The technology is expected to support China's crewed lunar landing, lunar research station, and deep-space exploration programs.

China Achieves First Bidirectional Laser Communication at 400,000 km Earth-Moon Distance

On August 26, 2026, the Technology and Engineering Center for Space Utilization (CAS) announced that China had, for the first time, established a bidirectional laser link over an Earth-Moon distance exceeding 400,000 km — uplink at 1.25 Mbps and downlink at 100 Mbps. An 8K lunar surface image can now be downloaded in about 12 seconds, compared with 4-5 minutes over a conventional 5 Mbps microwave link. China's space laser communications have officially moved from low Earth orbit into cislunar space.

This was not a single-button experiment: it caps five years of development plus over a year of in-orbit testing. Even more dramatically, the DRO-A satellite performing the experiment had survived a near-death launch experience (see below).

Key points

First bidirectional laser link at Earth-Moon distance (>400,000 km): uplink 1.25 Mbps, downlink 100 Mbps; 8K lunar images transmitted in ~12 seconds vs 4-5 minutes via 5 Mbps microwave.
Three core challenges ("three mountains"):
Precision: a laser beam is extremely narrow; a tiny angular error at 400,000 km can miss the target by kilometers. Researcher Li Chao of Zhejiang Lab likened it to "threading a needle" — passing an extremely thin beam through a fast-moving "needle hole."
Weak signal: after 400,000 km, only a few photons reach the ground telescope amid moonlight, starlight, and city lights. The team used high-speed superconducting single-photon array detectors with high-sensitivity processing algorithms.
Speed: major gains in data processing enabled the achieved uplink/downlink rates.
Why DRO: the Distant Retrograde Orbit offers stable parking (low station-keeping), low-energy transfer from LEO, and an ideal staging point for future Earth-Moon transportation. China's DRO-A/DRO-B/DRO-L satellites form the world's first three-satellite constellation in cislunar space based on DRO.
Satellite rescue: launched in March 2024, DRO-A/B's upper stage malfunctioned and the stack missed its target orbit. Through repeated perigee maneuvers covering nearly 8.5 million km of travel, engineers recovered the satellites to the intended orbit; the twin satellites separated in August 2024 and joined DRO-L to form the constellation. The historic laser link was achieved on this rescued satellite.
Multi-institution effort: CAS Technology and Engineering Center for Space Utilization (lead + flight payload), Zhejiang Lab (payload development), CAS Yunnan Observatories (ground optical tracking), CAS Shanghai Institute of Microsystem and Information Technology (single-photon detection).

International context

The US and Europe have longer records in space laser communications: NASA's LCRD (launched 2021, geostationary), ESA's EDRS, and NASA's Psyche Deep Space Optical Communications (267 Mbps from 16 million miles in 2023). China's milestone is distinct not in raw speed but in distance regime: it is the first bidirectional laser link at Earth-Moon range — a paradigm jump from near-Earth to cislunar communications.

What's next

Team lead Yang Lei stated that the Earth-Moon "information highway" is now open, and the technology will provide a new high-speed data transmission method for China's crewed lunar landing, lunar research station construction, and deep-space exploration. Expected milestones include routine operation of the link and science data downlink (late 2026–2027), validation for crewed lunar missions (2027–2028), and operational support for the lunar research station (2028+).

For consumers, maturing laser communications could mean faster satellite internet, better coverage in oceans and remote regions, improved navigation timing accuracy, and new commercial space applications — though terminal miniaturization and cost reduction remain the next engineering hurdles.

Reference data

| Dimension | Value | |---|---| | Distance | 400,000+ km | | Uplink | 1.25 Mbps | | Downlink | 100 Mbps | | 8K lunar image | 12 s (vs 4-5 min microwave) | | Development | 5 years + 1 year in-orbit testing | | Satellite | DRO-A (rescued after 8.5M-km recovery trajectory) |

References

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
China News Service coverage (2026-08-26): https://www.toutiao.com/article/7678322415943893556
Sohu/163 report (2026-08-26): https://www.163.com/dy/article/L59QQ2O005119RIN.html
DoNews report (2026-08-26): https://www.donews.com/news/detail/8/6686582.html