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Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePossibly—but this is a proposed technique, not an upgrade to operational U.S. GPS. A 2026 study used real inter-satellite measurements from China’s BeiDou-3 constellation and simulated links to four satellites in lunar orbit. In its 60-day analysis, the joint Earth–Moon solution reported a lower BeiDou-3 user range error than either of the two comparison cases. The lunar links were simulated, so the result does not show that a working Earth–Moon navigation network exists.
Why ranging between satellites may not be enough
Navigation satellites can measure distances to one another and use those measurements to estimate their orbits without relying continuously on ground stations. But relative ranging has a blind spot: it can establish the constellation’s internal geometry without establishing its absolute orientation relative to Earth. If the whole constellation rotates together, its satellites may still agree on their positions relative to one another while the shared orientation drifts.
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That distinction matters for autonomous orbit determination. A ground control segment can monitor satellites and send commands or reposition them; GPS.gov describes those functions as part of the U.S. system’s control segment. If ground-based corrections are unavailable, inter-satellite measurements alone may not reveal this common rotation.
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The proposed method adds satellites in elliptical lunar frozen orbits (ELFOs) to the ranging network. The idea is that Earth-orbiting and lunar-orbiting satellites move under different orbital conditions, including the influence of lunar gravity. Their cross-link measurements could therefore provide information that makes the constellation’s shared rotation observable, rather than merely preserving distances within the Earth-orbiting group.
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The paper, “Preliminary analysis for the joint autonomous orbit determination of the BDS-3 MEO satellites and lunar ELFO satellites based on inter-satellite links,” by Xia Lin and colleagues, was published in Satellite Navigation on September 17, 2026, according to the research release. The analysis combined onboard inter-satellite link measurements from 24 BeiDou-3 medium Earth orbit (MEO) satellites with simulated cross-links to four ELFO satellites. It did not use operational lunar links.
What the 60-day comparison found
The research release reports these BeiDou-3 user range errors after the study’s 60-day interval:
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| Study case | Rotational correction | Reported BeiDou-3 user range error after 60 days | Role of lunar links |
|---|---|---|---|
| No rotational correction | None | 7.85 m | No lunar reference used |
| Prediction-based correction | Based on orbit prediction | 0.60 m | No lunar reference used |
| Joint Earth–Moon solution | Estimated jointly using Earth- and lunar-orbit satellites | 0.35 m | Cross-links to four lunar satellites were simulated |
These figures are results reported by the 2026 research release, not guaranteed service levels or measurements from an operating GPS system. They describe BeiDou-3 study cases; the data do not establish how the method would perform on U.S. GPS or in an actual outage.
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1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsThe release also reports maximum simulated ELFO-satellite position errors of less than 0.16 m in the radial direction, 1.7 m along track and 1.8 m cross track. Separately, it says the position-information matrix condition number changed from approximately 1015–1018 with MEO satellites alone to about 102 when four ELFO satellites were added. These are reported values from the release; they should not be read as independently verified operational performance.
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What this means for GPS—and what it does not
The title uses “GPS” in the familiar, broad sense of satellite navigation. The study’s measured constellation was BeiDou-3, not the U.S. GPS constellation. It proposes a possible method for navigation constellations; it does not show that GPS currently uses lunar satellites or has adopted the approach.
GPS.gov says GPS satellites operate in MEO at approximately 20,200 km altitude in six orbital planes. The U.S. aims to maintain at least 24 operational GPS satellites 95% of the time. The same GPS.gov page gives a count of 31 operational satellites as of July 3, 2023; that dated figure is not a current status count.
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This concept is also different from using navigation satellites to serve users on the Moon. NASA’s lunar Position, Navigation, and Timing architecture describes limitations of GPS signals at the Moon, including weak signals, satellite geometry and Earth occultation. A lunar network could serve future lunar-surface and cislunar users, while the BeiDou-3 study examines the distinct possibility of using lunar-orbit satellites as a reference for Earth-orbit navigation.
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NASA has separately assessed candidate lunar navigation constellations. One study found a three-plane Walker constellation at six lunar radii to be a good candidate for lunar PNT, while noting that other options may suit different coverage needs. That is design analysis, not evidence of a deployed network, and it does not establish that the NASA constellation is the one modeled in the BeiDou-3 study.
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Has a lunar satellite network been tested?
The study used real onboard BeiDou-3 measurements, but simulated the cross-links to the four lunar satellites. It therefore tested the proposed joint solution in analysis, not through real onboard lunar observations or a deployed Earth–Moon network. The research release identifies replacing simulated lunar links with real onboard observations and developing link scheduling for lunar PNT users as future work.
The result is an early demonstration of a potential way to address a specific observability problem. A 60-day simulation does not establish long-term reliability, performance during real ground-segment outages, or readiness for operational use. The release summarizes the paper; its reported figures should be understood in that context.
Would this change anything for a phone or car GPS receiver?
No consumer receiver can enable or use the proposed satellite-to-satellite Earth–Moon cross-links. The concept concerns spacecraft-level orbit determination and links among navigation satellites, not a setting, accessory or feature available in ordinary GPS devices.
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