Foresail-1 Prime: Early In-Orbit Results and Platform Performance

This presentation reports first in-orbit results from the FORESAIL-1 Prime mission [1], launched in November 2025 aboard the Transporter-15 mission from Vandenberg Space Force Base. FORESAIL-1 Prime is a 3U CubeSat built on a fully redeveloped, mission-specific satellite platform, designed and implemented at Aalto University following a comprehensive re-engineering of the original FORESAIL-1 spacecraft. All major subsystems, meet the mission’s scientific and technological requirements.

Since launch, the satellite has completed commissioning and entered stable routine operations. Platform performance has been nominal, demonstrating robust power generation, reliable thermal behavior, and consistent attitude control. A major early achievement has been the successful in-orbit validation of a newly developed radio communication protocol, tailored for small satellite operations. The protocol has enabled flexible on-orbit configuration, reliable command and telemetry exchange, and efficient science data transfer, confirming the maturity of the custom communications stack and ground segment.

The mission’s primary scientific payload, the Particle Telescope (PATE) developed by the University of Turku, is fully operational and supported by the new platform architecture. The detector has been integrated into routine operations, with autonomous payload scheduling, health monitoring, and data handling performed by the onboard software. First in-orbit measurements show stable detector performance, validating both the instrument and the supporting spacecraft systems.

FORESAIL-1 Prime also carries a plasma brake developed by the Finnish Meteorological Institute to investigate electrostatic deorbiting. Initial in-orbit activation tests have been successfully conducted, confirming basic tether functionality and spacecraft compatibility.

This presentation focuses on the design philosophy, in-orbit behavior, and early operational experience of the FORESAIL-1 Prime platform, highlighting how a fully custom, university-developed CubeSat architecture can achieve reliable performance while supporting demanding science and technology demonstration objectives.