EnduroSat raises over $100 million and opens large-scale Space Center to accelerate ESPA-class satellite production
- ›EnduroSat announced a funding round of just over $100 million led by venture and institutional backers including Riot Ventures, Google Ventures, Lux Capital, the EIC Fund and Shrug Capital.
- ›The company opened a 188,340 square foot Space Center in Sofia designed to produce up to two ESPA-class satellites per day, targeting 200 to 500 kilogram satellites.
- ›EnduroSat highlights a cableless, modular Frame ESPA-class bus that it says can be assembled and tested in hours, aiming to serve growing demand for small and mid-size constellations.
- ›An EIC-funded Pathfinder project called S4I2T is developing solar electric water electrolysis propulsion and autonomous refuelling concepts intended to support a circular space economy.
- ›Claims of rapid mass production and wide market access are significant but face practical constraints including launch capacity, qualification cycles, supply chain limits and regulatory requirements.
EnduroSat raises funding and opens a high-volume Space Center to scale ESPA-class satellite production
EnduroSat, a Sofia based satellite manufacturer that has described itself as a provider of satellite constellations as a service, announced on 30 October 2025 a new financing round totaling just over one hundred million US dollars. Investors named in the company release include Riot Ventures, GV or Google Ventures, Lux Capital, the European Innovation Council Fund and Shrug Capital. The announcement coincides with the official opening of a new 188,340 square foot Space Center in Sofia. EnduroSat says the facility will enable high volume production of modular ESPA class satellites and that it can produce up to two 200 to 500 kilogram satellites per day.
What the funding round covers and who backed it
Company statements say the proceeds will be used to scale production of EnduroSat’s Frame ESPA class satellite buses and to accelerate delivery of constellation solutions for commercial and government customers. EnduroSat frames this as validation of market traction and a step towards making space derived data more broadly available. The press release highlights the participation of the European Innovation Council Fund which framed its investment as support for Europe’s deep tech and space leadership.
| Item | Detail | Source or status |
| Announced funding | Over $100 million reported, company pages also state $104 million | EnduroSat press materials |
| Lead investors named | Riot Ventures, Google Ventures (GV), Lux Capital, EIC Fund, Shrug Capital | EnduroSat press materials |
| Investor allocations | Individual amounts not disclosed | EnduroSat press materials |
| Use of proceeds | Scale production of modular satellite buses and Space Center operations | EnduroSat press materials |
The new Space Center and claimed production capacity
EnduroSat describes the new Sofia Space Center as a large scale manufacturing and test complex. The site is said to include advanced radio frequency laboratories, hardware and mechanical labs, ISO class clean rooms and space qualification facilities. Company materials claim the facility can support manufacturing of up to two ESPA class satellites per day in the 200 to 500 kilogram mass range. The announcement positions this capacity as a response to rising demand for small to mid sized constellations from commercial and sovereign customers.
| Facility attribute | Specification |
| Footprint | 188,340 square feet |
| Target daily production | Up to two ESPA-class satellites per day |
| Satellite class targeted | 200 to 500 kilograms, ESPA-class Frame bus |
| Key features | Advanced RF labs, mechanical labs, ISO-class clean rooms, space qualification facilities |
Technical product details offered by EnduroSat
Product pages provide more granular specifications for the Frame ESPA class bus. Published numbers include a bus mass of about 80 to 90 kilograms, available payload mass up to 70 kilograms, peak input power up to 600 watts and an advertised average payload power range between about 115 and 440 watts depending on orbit and local time of ascending node. Pointing accuracy claims are under 0.1 degrees and payload gross data rates are promoted up to 2 gigabits per second. The company also lists software toolkits, in orbit operations suites and standardization for certain ground and data networks.
| Frame bus parameter | Value |
| Bus mass | 80 to 90 kg |
| Available payload mass | Up to 70 kg |
| Payload volume envelope | Up to 500 x 1100 x 850 mm |
| Peak input power | 600 W |
| Payload gross data rate | Up to 2 Gbps |
| Pointing accuracy | <0.1 degree (3 sigma) |
| Delta V capacity | 40 to 400 m/sec depending on configuration |
EIC Pathfinder project S4I2T and propulsion ambitions
Alongside the funding announcement EnduroSat materials reference an EIC Pathfinder funded project called S4I2T which began in September 2024. S4I2T aims to demonstrate technologies for a circular space economy with a focus on a solar electric water propulsion architecture. The project scope includes electrolysis based propulsion using water as propellant, autonomous proximity operations for docking and refuelling, and techniques for extracting water in space from celestial bodies. The stated goal is to enable in orbit refuelling, in serviceability and long duration, Earth independent operations.
S4I2T’s ambitions, if realised, would be meaningful for long lived missions, in orbit servicing and nascent in situ resource utilisation. The project aligns with European research priorities on sustainability and space autonomy. At the same time the technological leap from lab scale demonstrations to operational, safety certified in orbit refuelling remains substantial.
Market context and why EnduroSat is pitching scale
Demand for smaller and mid sized constellations has grown for applications such as dedicated government communications, earth observation for agriculture and infrastructure, and vertical market services. These constellations differ from mega constellations like Starlink in scale and often in governance. EnduroSat positions itself to serve customers who want their own dedicated networks rather than relying on third party operators.
Investors referenced public endorsements in the release. Venture partners framed the company as following an industrialisation playbook, moving from subsystem manufacture to full stack satellite production. The EIC Fund presented the investment as reinforcing European leadership in space tech.
Risks, constraints and outstanding questions
The claims in the company announcement are notable but several operational and market constraints remain. Producing two ESPA class satellites per day requires a steady and qualified supply of components, a scalable quality assurance and qualification pipeline, and a launch cadence that allows timely deployment. Launch capacity and rideshare manifests are finite and can be a bottleneck for rapid constellation growth. Defence and government customers often require additional security clearances, testing and long acceptance cycles which can slow revenue realisation.
Other questions include how much of the reported funding is growth capital versus bridge funding, whether investor support includes introductions to anchor customers, what per unit production costs will be at scale, and how many launch slots are committed to deploy the fleets that EnduroSat aims to build. Transparency on unit economics and committed purchase orders will be the next signals to watch.
Why the EIC Fund matters here
Conclusion and outlook
EnduroSat’s announcement is a clear signal that investors see opportunity in industrialising satellite production in Europe. The new Space Center and the company’s Frame bus specifications are credible steps toward higher throughput manufacturing. The S4I2T Pathfinder project reflects an ambition to pair production scale with new propulsion and in orbit servicing capabilities. At the same time the transition from prototype to consistent, reliably flight proven mass production faces well known technical, supply chain and regulatory hurdles. Progress should be measured by future evidence of sustained launch cadence, third party flight heritage, customer contracts and transparent unit economics rather than by headline production claims alone.
This article is based on EnduroSat press materials published 30 October 2025 and related company pages. Where possible the company claims are reported exactly and contextual observations draw on common industry constraints and the role of EU innovation financing structures.