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Search Continues for STMSat-1 Radio Signal


Youngsters at St Thomas More Cathedral School in Virginia remain optimistic that their STMSat-1 CubeSat, deployed on May 16 from the International Space Station, will begin transmitting a signal. The CubeSat was rebooted from the ground just after 0400 UTC on May 24. Helping in the search is the Space Science Center at Morehead State University in Kentucky, which is using its 21 meter dish to scan multiple frequencies for the spacecraft’s signal. STMSat-1 is supposed to transmit on 437.800 MHz FM and transmit slow-scan television (SSTV) pictures back to Earth.

“Morehead University picked up something within our frequency range last night,” STMSat-1 Education Manager Emily Stocker said May 25 in response to an ARRL inquire. “It may have been us; it is possible it was MinXSS.” The University of Colorado’s MinXSS was deployed from the ISS at the same time as STMSat-1. Stocker said they were trying to determine if Morehead State picked up a beacon, which probably would suggest a MinXSS signal, or SSTV data, which would likely confirm a signal from STMSat-1. In addition, JA0CAW posted a tweet reporting a signal heard on 437.800 MHz at 1225 UTC on May 25.

The signal to reboot STMSat-1 was scheduled after the satellite had not been heard from for 7 days. STMSat-1 was supposed to turn itself on once its batteries were fully charged and its mechanized antennas deployed.

Pupils at the school built STMSat-1 during a 4-year-long project, and the satellite was launched to the ISS last December. After being placed in orbit (it is object 41476), the CubeSat initially continued roughly in the same orbit as the ISS and of other satellites deployed on May 16, but it’s been moving away a little bit each day. The youngsters have been tracking its orbit.

The satellite is designed to transmit slow-scan television (SSTV) images (Robot 72) of Earth on 437.800 MHz FM. Stocker advised all those interested to follow the STMSat-1 Twitter feed, @STMSat11, to stay up to date.

The satellite is the first to be designed and built by grade schoolers, who were supported by NASA technical advisors and local radio amateurs. NASA’s Technology Demonstration Office provided the school with a mobile “clean room” for the construction and a ground-station antenna. The agency has been advising the school on tracking the satellite and finding its signal.