Re-post from ANS-313:
The CatSat team has announced that preparations are underway to open public operation of the spacecraft’s linear transponder, offering the amateur-radio community a new microwave-band satellite resource. CatSat, a 6U CubeSat developed and flown by students, faculty, and staff at the University of Arizona in partnership with FreeFall Aerospace and Rincon Research, has been on orbit since July 2024 and is now entering the phase of its mission focused on community engagement and technology demonstration.
CatSat was launched aboard a Firefly Aerospace Alpha rocket from Vandenberg Space Force Base as part of NASA’s CubeSat Launch Initiative. Measuring roughly the size of a family-size cereal box, the spacecraft carries a suite of experimental payloads, including a novel inflatable antenna capable of enabling large-aperture communications from a small satellite platform. In addition to ionospheric monitoring via high-frequency (HF) radio measurements and imaging of the Earth, CatSat includes a linear transponder for amateur radio, extending the University of Arizona’s long legacy in space science down to hands-on student involvement.
The satellite orbits Earth in a nearly sun-synchronous polar orbit, circling the globe approximately every 90 minutes. As part of its student-driven mission, CatSat is demonstrating how cutting-edge antenna systems and commercial-off-the-shelf radio hardware can support meaningful research and amateur communications from a compact form factor. The mission is funded by the University of Arizona Office of the Vice President for Research and the Arizona Space Institute, with additional support from industry partners.
When the linear transponder is active, CatSat listens on 5.663 GHz (uplink) and transmits on 10.47 GHz (downlink), providing approximately 200 kHz of bandwidth. Patch antennas on the spacecraft’s −Y face offer roughly 60-degree beam coverage, and the attitude-control system can point the antenna footprint at ground stations for up to 10 minutes per pass. Power considerations limit each activation to about 15 minutes, a balance that allows the spacecraft to support both mission science and amateur communications.
Early on-orbit demonstrations used a 1-meter C-band uplink dish and a 6.1-meter X-band downlink dish to confirm transponder functionality, successfully relaying Morse code. The CatSat team is now constructing a more accessible ground station using 1-meter-class commercial antennas to show that amateur access is practical with reasonably sized equipment. Operators will be able to monitor schedule updates — informally known as the “five and dime” plan — through the CatSat mission website.
Commissioning passes targeting the CatSat ground stations in Tucson took place on October 29 and November 2, with one final activation scheduled for November 9 at approximately 7:50 PM MST (UTC-7) — just hours after this bulletin’s publication. As testing continues, dates may shift as the team evaluates performance and power-budget constraints. Operators can follow activation plans and future opportunities at https://catsat.arizona.edu.
Read the full announcement at: https://catsat.arizona.edu/news/catsat-team-preparing-public-linear-transponder-operations
[ANS thanks the CatSat Team and the University of Arizona for the above information]