New Satellite Tracking Application Released

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Bob McGwier, N4HY, has announced the release of a new satellite tracking application entitled Visible Ephemeris.

Visible Ephemeris is a modern, spiritual successor to Quiktrak (1986), re-engineered for the Raspberry Pi 5 and modern silicon. It is capable of propagating 13,000+ satellites in real-time with sub-second updates while maintaining <5% CPU utilisation. Visible Ephemeris is high performance physics-based program using Kelso/Villado SGP4 to track satellites (all in the Celestrak TLE). It uses McGwier’s implementation of Pedro Escobal AOS/LOS search, but rewritten for altitude and not Eccentric Anomaly. The code is designed for and intended for the Raspberry Pi and displays graphics components using Web UI.

It features a Hybrid Decoupled Architecture where the UI, Orbital Mechanics, and Network Services run on independent threads, ensuring the interface never freezes—even during heavy calculation loads.

Visible Ephemeris has been released under the MIT license and further details can be found at https://github.com/n4hy/VisibleEphemerisCPP.git

Happy 12th Birthday to AO-73 (FUNcube-1)

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Happy 12th Birthday to AO-73 (FUNcube-1)

AO-73 celebrated its 12th birthday on 21 November 2025. The satellite is still operating well in full-time transponder mode.

On 21 November 2013, FUNcube-1 (AO-73) was launched from the Yasny launch base located in the Orenburg Region, Russia, on a Dnepr Launch Vehicle into a 600 km, 97.8º inclination sun-synchronous orbit. In this orbit, the satellite passes over the British Isles and Europe approximately 3 times in the morning, and 3 times in the evening, every day, perhaps allowing the morning passes to be used for educational purposes and the evening passes for Amateur Radio communications.

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Is AO-7 Still the Oldest Satellite?

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AMSAT-OSCAR 7, or AO-7, is the second Phase 2 amateur radio satellite constructed by the Radio Amateur Satellite Corporation (AMSAT). It was launched into Low Earth Orbit on 15 November 1974 and remained operational until a battery failure in 1981. After 21 years of apparent silence, the satellite was heard again on 21 June 2002 – 27 years after launch, and it continues to be used by amateurs daily even now. For a couple of decades, AMSAT has been able to proudly boast that this bird is the oldest operating satellite in space.

However, that record has been challenged. After 47 years of silence, LES-1, a satellite launched by the U.S. Air Force and MIT’s Lincoln Laboratory in 1965, began transmitting again. Its signals were detected by Phil Williams, G3YPQ, from North Cornwall in southwest England on 18 December 2012, verified by other members of the Hearsat group, Flávio A. B. Archangelo, PY2ZX, in Brazil on 22 December 2012, and Matthias Bopp, DD1US, in Germany on 27 December 2012.

According to Williams, LES-1 was determined to be tumbling with a rotation rate of once every four seconds, as determined by distinctive fading of the signals. It is possible that, after 47 years, the batteries failed in a manner that allows them to carry charge directly through to the transmitter on 237 MHz, allowing the satellite to resume transmissions when it is in sunlight. The satellite continues to be operational as tracked by the SatNOGS network.