239Alferov (239PTS, FTS 239, RS61S)

239Alferov [Geoskan]

239Alferov is a Russian 3U CubeSat nanosatellite developed by Presidential Physics and Mathematics Lyceum No. 239 and the Zh. I. Alferov Physical-Technical School within the Space-Pi project of the Planet Watch program (FASIE). The spacecraft uses the Geoskan 3U platform and carries a cosmic gamma-ray transient monitor and the VERA ablative pulsed plasma thruster.

The mission aims to study transient gamma-ray phenomena of extragalactic, galactic, solar, and terrestrial origin. Target sources include gamma-ray bursts, neutron-star flares, solar flares, and lightning-generated gamma radiation. The onboard instrument enables continuous monitoring of the high-energy environment and contributes to research in modern astrophysics.

The cosmic gamma-ray transient monitor is a scintillation detector based on thallium-doped sodium iodide (NaI(Tl)) coupled with silicon photomultipliers. The system provides a sensitive gamma-ray spectrometer with an active detector area of approximately 50 cm². Scientific leadership of the experiment is provided by Dmitry D. Frederiks and Dmitry S. Svinkin of the Laboratory of Experimental Astrophysics, Ioffe Institute.

An additional educational objective is incorporated into the mission. Students working with 239 Alferov gain experience in high-energy astrophysics, gamma-detector design, and data-analysis techniques. The project supports early involvement in space instrumentation and scientific research. The satellite also stores names and images submitted through the “Send Your Name into Space” campaign in a dedicated onboard memory sector.

The spacecraft is built on the Geoskan 3U platform, a standardized Russian nanosatellite bus used for educational and scientific missions. The platform supports compact scientific payloads, low-power instruments, and experimental propulsion modules. The VERA ablative pulsed plasma thruster provides an additional opportunity to test small-satellite propulsion technology in orbit.

Technical properties include a 3U CubeSat form factor, integrated power and communication subsystems, and payload accommodations for the gamma-ray monitor and VERA thruster. The detector is mounted to provide an unobstructed field of view for transient-event detection. Data handling is supported by an onboard computer with designated storage for mission telemetry and outreach materials.