EnduroSat's EIC Accelerator Equity Came Before the Unicorn Round

Most EIC Accelerator winners take a grant. EnduroSat took only shares. The Bulgarian satellite maker was selected at the October 2024 cut-off for an equity-only award for SD-IRS, a software-defined integrated radio system that is meant to handle both high-speed data downlink and links between satellites from a single terminal. The EIC's own page lists the support as a €10 million equity investment.

The money arrived in a much larger round. In October 2025 the EIC Fund joined Riot Ventures, GV, Lux Capital and Shrug Capital in a $104 million round, and in September 2026 EnduroSat raised another $205 million at a valuation its marketing director said "significantly exceeded" $1 billion, which the Bulgarian news agency BTA reports makes it Bulgaria's second tech unicorn after Payhawk. The radio the award was for is harder to find in public.

From a university CubeSat to satellite buses

EnduroSat was founded in Sofia in 2015 by Raycho Raychev and launched the first Bulgarian CubeSat, EnduroSat One, in May 2018, according to the mission list on Wikipedia. Its missions since then have carried payloads for Foxconn, IBM, Hubble Network, Sateliot and the Kenyan and Botswanan space programmes, among others.

Its business model is what it calls constellations as a service: customers rent space on standard EnduroSat satellites or buy satellite buses, the platforms that carry a customer's instrument, and EnduroSat builds and operates them. The current flagship is FRAME, a line of ESPA-class satellites of 200 to 500 kilograms. In September 2026 Vantor chose EnduroSat to supply the buses for 24 satellites of its Pulse imaging constellation, with CACI building the cameras, Payload reported.

Debt first, then four equity rounds

EnduroSat's first large financing was debt. In July 2021 the European Investment Bank signed €10 million of venture debt with EnduroSat AD, the group parent, toward a €20 million investment plan in space infrastructure and expansion; the group then employed more than 70 people.

The equity came later and fast. A €20 million round led by CEECAT Capital preceded the 2025 rounds; The Recursive dates it to February 2023, while Capital's article on a €20 million raise is dated 27 February 2025. In May 2025 Founders Fund led a €43 million Series B with CEECAT and Morphosis Capital. On 31 October 2025 EnduroSat announced $104 million, about €90 million, from Riot Ventures, GV, Lux Capital, the European Innovation Council Fund and Shrug Capital, and opened its Sofia Space Center, built to produce up to two ESPA-class satellites a day.

On 16 September 2026 came $205 million, co-led by Riot Ventures and Atreides Management with the European Innovation Council, GV, Founders Fund, House Capital, Lux Capital, Omnes Capital, Giant Ventures, Emphatic Capital and Endeavor Catalyst, according to Evertiq and Payload. The money is for larger FRAME spacecraft, a high-volume factory in the United States and what the company calls the EU's largest space and defence hub in Bulgaria. EnduroSat did not publish the valuation; its marketing director told the Bulgarian news agency BTA that it "significantly exceeded USD 1 billion".

Revenue figures come from the company and are preliminary. EnduroSat expected to roughly double revenue in 2023 to about 27 million leva, around €13.5 million, according to Capital in March 2024, and put 2025 revenue at €34 million to €35 million, up more than 55% on 2024, according to Capital in July 2026. Audited accounts from the Bulgarian commercial register were not obtained for this article, so profit and losses are not known here.

SD-IRS: the radio behind the award

The EIC describes SD-IRS as the first fully integrated, low-cost satellite communication system that "delivers high-speed data downlink and autonomous inter-satellite connectivity from a single terminal". Combining ground and satellite-to-satellite links in one low-cost unit is aimed at constellations of many small satellites. The EIC page links the radio to the FRAME platform and to industrial-scale production.

Because the award was equity only, there is no grant agreement, no CORDIS project page and no periodic report to check what SD-IRS has delivered. EnduroSat's 2025 and 2026 funding announcements speak about satellite production, FRAME and the Space Center, not about the radio, and none of the sources found for this article dates a launch or a first mission for SD-IRS. Whether it flies on FRAME satellites today is not public.

1. EIC equity investedDoneEIC Fund named among investors in the October 2025 round; €10M per the EIC.
2. SD-IRS radio in serviceNot documentedNo public launch date or mission found.
3. Industrial-scale satellite productionUnder waySofia Space Center opened in 2025, rated for up to two satellites a day.
4. Commercial scaleGrowingVantor order for 24 buses; preliminary 2025 revenue of €34M to €35M.

A European satellite factory with US money

EnduroSat builds its satellites in Sofia and plans what it calls the EU's largest space and defence hub there, which fits the EU's aim of building its own space capacity. Its 2026 round also shows the limits of that aim: the round was co-led by two US investors, and part of the money goes into a factory in the United States. The EIC Fund's presence in both of the last two rounds keeps a European public shareholder in the company as it grows on both sides of the Atlantic.