EnduroSat
Bulgarian smallsat platform manufacturer headquartered in Sofia (founded 2015). Modular CubeSat platforms across 1U through 16U form factors and ESPA-class FRAME family (FRAME S, FRAME L, FRAME Max). Subsystems (OBC, EPS, ADCS, S-Band/X-Band) sold discrete. Space Service offering wraps mission design, integration, launch procurement, and operations as a fixed-cost package. Developing the Balkan multispectral constellation (120 nanosats, 1.5 m GSD, Copernicus Contributing Mission candidate).
EnduroSat (legal name: EnduroSat AD) is a Bulgarian private smallsat manufacturer and space service provider headquartered in Sofia, founded in 2015 by Raycho Raychev. The company designs, builds, and operates CubeSat and microsatellite platforms, supplying bus hardware directly to customers and offering end-to-end mission services through its Space Service programme.[^endurosat-about]
The platform portfolio spans three classes. The CubeSat line covers 1U through 16U form factors, with the 6U, 8U, and 16U platforms carrying declared flight heritage.[^endurosat-home] The 16U accommodates payloads of up to 24.5 kg with 25-60 W average power and a 1 Gbps X-Band or K-Band downlink; the 8U supports up to 6.8 kg at 13-40 W with 150 Mbps X-Band; the 6U supports up to 7.8 kg at 10-30 W with 150 Mbps and optional 0.01-degree three-axis attitude control.[^endurosat-platforms] All platforms share a modular subsystem architecture built around EnduroSat's own OBC, EPS, ADCS, and S-Band or X-Band transceiver modules, which are also sold as discrete components.[^endurosat-obc]
The FRAME family targets ESPA-class missions from 85 kg (FRAME S, 15-inch) through 250 kg (FRAME L, 24-inch) to 500 kg base (FRAME Max).[^endurosat-frame-s][^endurosat-frame-l] FRAME L supports up to 300 kg of payload at 1 kW average power with 4 Gbps downlink and sub-0.06-degree nadir pointing. The cableless modular design is stated to allow a single technician to assemble and functionally test an ESPA-class satellite in 8 hours.[^endurosat-frame-l] Production scaling was backed by EUR 43M in May 2025 (Founders Fund-led) and $104M in October 2025 (Riot Ventures, GV, Lux Capital, EIC Fund), targeting the Sofia Space Center.[^endurosat-funding-104m][^endurosat-funding-43m]
The Space Service offering provides mission design, integration, launch procurement, and operations as a fixed-cost package, with a stated 6-month time-to-orbit from requirements sign-off.[^endurosat-space-service] A shared satellite variant flies multiple customer payloads on a single bus, with SPARTAN (June 2021, 7 payloads) as the first operational example.[^endurosat-spartan] TAIFA-1, a hyperspectral 3U EO satellite for SayariLabs and the Kenya Space Agency, launched in April 2023 as the most-cited EO customer mission on an EnduroSat bus.[^endurosat-taifa]
EnduroSat is developing the Balkan constellation: 120 nanosatellites at 500 km targeting 1.5-hour revisit, with 1.5 m multispectral imagery in 7 bands aligned to Sentinel-2 VNIR, selected as a Copernicus Contributing Mission candidate by ESA and the EU.[^balkan-constellation] Balkan-1, the pilot 16U satellite, launched on Transporter 12 in January 2025 and carries onboard AI event-detection processing developed by Agenium.[^balkan-1-news]
As of 2026, EnduroSat reports more than 80 satellites in orbit with 3,500+ modules deployed, employs approximately 325 staff across Sofia, Italy, France, and US operations, and claims 400+ customers across commercial and institutional segments.[^endurosat-about]