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Radio Amateurs Report Hearing 4M Moon Orbiter JT65B Signal


[UPDATED 2014-10-24 1942 UTC] A Chinese Long March 3C/G2 rocket carried the Manfred Memorial Moon Mission (4M) lunar flyby experiment into space at 1759 UTC on October 23, on its way to a lunar transfer orbit and a return to Earth in about 9 days. Radio amateurs in Oceania and Europe have reported hearing the JT65B from the onboard Amateur Radio payload. Lunar flyby is to occur, nominally, on October 28, and the Amateur Radio package will transmit continuously throughout the voyage. During the lunar flyby, the spacecraft will be about nearly 248,000 miles from Earth and between 7440 and 14,480 miles from the Moon. The 4M Amateur Radio payload is transmitting a WSJT JT65B beacon and telemetry on 145.980 MHz. Roland Zurmely, PY4ZBZ, in Brazil, was reported to be the first to receive telemetry from the JT65B beacon at 1918 UTC.

“A number of Australian radio amateurs have reported receiving the signals from 4M,” AMSAT-UK reported. “Among them was Rob Whitmore, VK3MQ, at Mount Dandenong, Victoria (QF22qe), who reports that, at best, the strength was 13 on the JT65B scale and could also be totally down into the noise with no decodes.”

Joe Taylor, K1JT, developed as version of his free WSJT software especially for this mission The 14 kg battery-powered 4M-LXS payload was developed at LUXspace in Luxembourg. The 4M transmitter runs 1.5 W into a simple quarter-wave monopole antenna.

In the Netherlands, Berend Udema, PA3ARK, copied the 4M experiment at a signal level of –8 dB. He used a TS-2000 and a 6 element Yagi. So far the decodes have included call sign, telemetry, and a story of Manfred Fuchs threading through alternate decodes,” AMSAT-UK quoted him as saying. LUXspace has been encouraging radio amateurs to receive and report the signals. LUXspace also has a 4M payload blog. AMSAT-UK earlier posted the Keplerian elements for the spacecraft.

“Strong 15 db signal over Buenos Aires,” reported Adrian Gabriel Sinclair, LU1CGB on the LUXspace blog. “Warehouse client works great, congratulations [on] a successful launch!”

The October 23 launch represents the third phase of its lunar exploration program, the Chang’e-5-T1 mission, aimed at validating technologies for a future lunar sample return probe. If successful, the mission will mark the first successful re-entry of a Chinese space vehicle into Earth’s atmosphere. The plan calls for a soft landing in the Inner Mongolia Autonomous Region of northern China.

The mission honors the late Professor Manfred Fuchs, founder of LUXspace’s parent, the OHB group, who died earlier this year. The 4M-LXS ham radio package carries up to 2500, 13-character digital messages into space for retransmission. The International Amateur Radio Union (IARU) is a partner in the experiment.

The 4M mission was detailed during a presentation the EME 2014 conference held recently in France. A paper, “4M Mission: A Lunar Flyby Experiment” also is available. — Thanks to LUXspace, AMSAT-UK, Xinhua,, and Huelbe Garcia, PU3HAG




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