Deep Space Energy is developing Americium-241 powered radioisotope generators for lunar missions and defense satellites. Image: Deep Space Energy
What is Deep Space Energy?
Deep Space Energy is a Riga-based SpaceTech startup developing next-generation radioisotope power generators for space missions and defense applications. Founded in 2022 by physicist Mihails Ščepanskis, the company has raised €930,000 to commercialise a nuclear battery technology that uses Americium-241 extracted from commercial nuclear reactor waste. The funding comprises a €350,000 pre-seed round led by Outlast Fund and angel investor Linas Sargautis, plus €580,000 in public contracts and grants from the European Space Agency (ESA), NATO DIANA, and the Latvian government.
The company’s technology addresses a critical gap in European space infrastructure: the lack of indigenous power systems for deep space missions and high-value defense satellites. Unlike solar panels that fail in permanent shadow or batteries that deplete, radioisotope generators provide continuous power for decades using the heat from radioactive decay.
The Technology: Americium-241 vs. Plutonium-238
Radioisotope power systems (RPS) have powered space exploration since 1961, including NASA’s Voyager probes, Curiosity Mars rover, and New Horizons mission to Pluto. Traditionally, these systems use Plutonium-238 (Pu-238), which has a half-life of 88 years and provides 0.56 watts of heat per gram. However, Pu-238 production is limited to the United States and Russia, creating strategic dependency for European space agencies.
Deep Space Energy’s innovation centres on Americium-241 (Am-241), a byproduct of Plutonium-241 decay found in spent nuclear fuel. With a half-life of 432 years, Am-241 offers five times longer operational lifespan than Pu-238. While it produces less heat per gram (0.15 W/g) and requires more shielding due to gamma radiation, it provides energy independence for Europe.
The company’s generator design achieves 5x fuel efficiency compared to legacy Radioisotope Thermoelectric Generators (RTGs), requiring only 2kg of Am-241 to generate 50W of power versus 10kg for conventional systems. This efficiency breakthrough is critical given projected Am-241 production capacity of approximately 10kg annually by the mid-2030s.
Mihails Ščepanskis, founder and CEO, explains: “Our technology, which has already been validated in the laboratory, has several applications across the defence and space sectors. We’re developing an auxiliary energy source to enhance the resilience of strategic satellites, providing backup power that does not depend on solar energy.”
The €187M European SpaceTech Wave
Deep Space Energy’s funding arrives amid unprecedented capital flow into European space technology. In 2025-2026, EU-Startups tracked approximately €187 million in disclosed funding across the sector, with significant rounds including:
Germany’s Reflex Aerospace secured €50 million for sovereign satellite platforms. France’s Infinite Orbits raised €40 million for in-orbit servicing capabilities. Look Up (France) attracted €50 million for radar-based space surveillance. UNIVITY (France) secured €31 million for space-based 5G constellations. Marble Imaging (Germany) raised €5.3 million for Earth observation satellites. Kreios Space (Spain) secured €8 million for very low Earth orbit propulsion. Astradyne (Italy) raised €2 million for ultralight solar panels. Orbital Paradigm (Spain) closed €1.5 million pre-seed for reusable space capsules.
Against this backdrop, Deep Space Energy’s €930,000 raise positions it at the proof-of-concept stage, focused on energy infrastructure rather than platform deployment. The company represents a niche but critical segment: power systems that enable all other space activities.
Defense and Strategic Applications
While lunar exploration captures headlines, Deep Space Energy’s immediate market centers on defense satellites. The company targets Medium Earth Orbit (MEO), Geostationary Orbit (GEO), and Highly Elliptical Orbit (HEO) satellites critical for military reconnaissance, synthetic aperture radar (SAR), signals intelligence, and missile launch detection.
The strategic rationale became starkly apparent in 2025 when Ukraine lost its beachhead in Russia’s Kursk Oblast following temporary termination of US satellite intelligence sharing. This incident highlighted Europe’s vulnerability: dependence on American space assets for high-value GEO satellite capabilities.
“As Europe is trying to become more independent, it is imperative to produce satellites with advanced capabilities on our own,” Ščepanskis notes. “Our technology provides an auxiliary energy source for satellites, which makes them more resilient to non-kinetic attacks and malfunctions.”
Radioisotope generators offer unique advantages for defense applications. Unlike solar panels, they cannot be disabled by adversarial dazzling or space weather events. They provide continuous power regardless of orbital position, eliminating the vulnerability of batteries during eclipse periods. For high-value military assets, this resilience justifies the premium cost and regulatory complexity of nuclear systems.
The Lunar Economy: Powering the Moon Village
Long-term, Deep Space Energy aims to serve the emerging lunar economy. NASA and ESA’s Artemis programme, the Argonaut lunar lander, and the Moon Village framework all require power systems that survive the lunar night, where temperatures drop below -150°C and darkness lasts 354 hours (approximately 14.75 Earth days).
Current lunar rovers rely on solar power with battery backup, limiting missions to single daylight periods. The Chinese Chang’e 4 lander and Yutu-2 rover survived lunar nights using radioisotope heater units, but full power generation requires more capable systems.
Deep Space Energy’s generator design specifically targets lunar night survival and operations in permanently shadowed regions, enabling extended scouting and resource prospecting missions. The company calculates that bringing payload to the Moon costs up to €1 million per kilogram. By extending rover lifetimes from single lunar days to multiple years, their technology could save hundreds of millions in launch costs while enabling more ambitious scientific and commercial objectives.
The timing aligns with ESA’s strategic shift toward Am-241. The agency has funded development of European Large Heat Sources (ELHS) using Am-241 at the UK National Nuclear Laboratory, with University of Leicester researchers leading Stirling converter development. NASA Glenn Research Center is testing Am-241 Stirling generators in partnership with Leicester, aiming for flight qualification by the late 2020s.
The Investors: Baltic SpaceTech Ecosystem
Outlast Fund, the lead investor, is a Riga- and Stockholm-based venture firm founded in 2024 by Egita Poļanska, Marija Rucevska, Kristaps Prusis, and Mikaela Pedersen. With a €21 million debut fund, Outlast focuses on pre-seed and seed-stage startups across the Baltics and Nordics, particularly in deep tech and hard science.
Egita Poļanska, partner at Outlast Fund, frames the investment in strategic terms: “Space energy tech has been stuck with certain limitations for decades, but we’re finally seeing the pieces come together for a real breakthrough. Deep Space Energy is building the infrastructure that will literally power the next chapter of space exploration and industry.”
The participation of Linas Sargautis brings significant space industry expertise. As co-founder and former Chief Commercial Officer of NanoAvionics, Sargautis helped build Lithuania’s first space unicorn, a small satellite manufacturer acquired by Kongsberg Defence & Aerospace in 2022 for approximately €65 million. His involvement provides Deep Space Energy with connections to leading space systems integrators and pathways to subsystem integration contracts.
“The Baltic region is increasingly recognised for its innovation in space technology,” Sargautis notes. “By supporting Deep Space Energy, we are helping to establish a solid foundation for the future of space frontier exploration, such as lunar and deep-space missions, expanding humanity’s knowledge and footprint, while also contributing to European space defence capabilities.”
The public funding component, €580,000 from ESA, NATO DIANA, and Latvian government sources, validates the technology’s strategic importance. NATO’s Defence Innovation Accelerator for the North Atlantic (DIANA) specifically targets dual-use technologies with defense and civilian applications, providing both funding and access to military end-users.
Competitive Landscape: Zeno Power and Global Race for Space Nuclear
Deep Space Energy enters a field with established competitors, most notably Zeno Power in the United States. Zeno Power has secured $45 million in venture funding and a $15 million NASA contract to develop Am-241 radioisotope power systems. In September 2025, Zeno signed a strategic agreement with Orano, the French nuclear fuel cycle company, to secure priority access to Am-241 from Orano’s La Hague recycling facility.
This agreement highlights the emerging supply chain for space nuclear fuel. Orano, one of the world’s largest nuclear fuel cycle companies, will recover Am-241 from spent nuclear fuel processed at La Hague. The collaboration demonstrates how European nuclear infrastructure can support space ambitions, creating potential partnerships for Deep Space Energy.
Other competitors include City Labs in the United States, which develops NanoTritium batteries using tritium (hydrogen-3) for small satellites and sensors. Tritium batteries provide lower power output (microwatts to milliwatts) but require minimal shielding and offer 20+ year lifespans. They complement rather than compete with Am-241 systems, serving different mission profiles.
The UK National Nuclear Laboratory and University of Leicester represent academic competition, developing Am-241 heat sources for ESA missions. However, their focus is on research and government programmes rather than commercial products, leaving room for startups like Deep Space Energy to industrialise and commercialise the technology.
Regulatory and Safety Considerations
Radioisotope power systems face significant regulatory hurdles. Launch safety requires demonstrating containment of nuclear material through worst-case accident scenarios, including launch vehicle explosions and re-entry heating. The United Nations Office for Outer Space Affairs (UNOOSA) maintains principles for nuclear power sources in space, requiring detailed safety analysis and notification to potentially affected states.
Deep Space Energy emphasizes that its technology is designed exclusively for peaceful applications. The company explicitly states its generators are “not designed for any kind of weapons” and target “high-value, dual-use satellites to increase their resilience and operational reliability.”
The use of Am-241 rather than Pu-238 offers some safety advantages. Am-241 produces less penetrating radiation than Pu-238, reducing shielding requirements for spacecraft electronics. Its longer half-life means lower initial radioactivity per gram, though the gamma radiation requires more substantial shielding for human protection during ground handling.
Roadmap and Technical Validation
With €930,000 in funding, Deep Space Energy will advance its radioisotope generator from laboratory validation toward commercial readiness. The immediate priorities include:
Subsystem Integration: Building expertise at the subsystem level to integrate heat sources, thermoelectric or Stirling converters, and thermal management systems.
Regulatory Engagement: Working with ESA and national regulators to establish qualification standards for Am-241 systems in European space missions.
Supply Chain Development: Securing access to Am-241 feedstock from European nuclear fuel reprocessing facilities, potentially partnering with Orano or UK National Nuclear Laboratory.
Customer Development: Engaging with satellite manufacturers and space agencies to define mission requirements and secure early adoption commitments.
The company targets the late 2020s for first flight missions, aligning with ESA’s lunar exploration timeline and NATO’s defense satellite modernisation programmes.
Conclusion: Powering European Space Independence
Deep Space Energy represents a critical piece of Europe’s space infrastructure puzzle. As the continent seeks strategic autonomy in defense and exploration, indigenous power systems become essential. The company’s Am-241 generators offer a path to energy independence for lunar missions and resilience for defense satellites, reducing reliance on American Pu-238 supplies.
The €930,000 raise, while modest compared to platform-focused SpaceTech startups, reflects the capital efficiency of deep tech hardware development in the Baltics. With experienced investors like Outlast Fund and Linas Sargautis, plus strategic public funding from ESA and NATO, Deep Space Energy has the resources and relationships to advance its technology toward commercialisation.
Whether Europe can establish a complete Am-241 supply chain and generator manufacturing capability remains uncertain. The competition with well-funded American companies like Zeno Power is real, and the regulatory pathway for space nuclear systems is complex. But the strategic imperative is clear: as space becomes the new economic and military frontier, power independence is foundational. Deep Space Energy is betting that Europe will pay a premium for that independence, and that the lunar economy will need batteries that work in permanent shadow.
FAQ: Deep Space Energy
What does Deep Space Energy do?
Deep Space Energy develops radioisotope power generators using Americium-241 nuclear fuel for space missions and defense satellites. The technology provides continuous power for decades in environments where solar energy is unavailable, such as lunar nights and deep space.
Who founded Deep Space Energy?
The company was founded in 2022 by Mihails Ščepanskis, a physicist and former researcher. He serves as CEO and has led the company through laboratory validation of its core technology and initial funding rounds.
How much funding has Deep Space Energy raised?
Deep Space Energy has raised €930,000 in total. This includes a €350,000 pre-seed round led by Outlast Fund and Linas Sargautis, plus €580,000 in public contracts and grants from the European Space Agency (ESA), NATO DIANA, and the Latvian government.
What is Americium-241 and why is it important?
Americium-241 is a radioactive isotope produced from Plutonium-241 decay in spent nuclear fuel. It has a half-life of 432 years (5x longer than Plutonium-238) and can be extracted from nuclear waste. For Europe, it offers energy independence for space missions, as Plutonium-238 is only produced in the US and Russia.
How does Deep Space Energy’s technology compare to traditional RTGs?
The company’s generators require 5 times less radioisotope fuel than legacy Radioisotope Thermoelectric Generators (RTGs), achieving 50W power output from 2kg of Am-241 versus 10kg for conventional systems. This efficiency is critical given limited Am-241 production capacity.
What are the main applications for this technology?
Primary applications include: (1) auxiliary power for high-value defense satellites in MEO, GEO, and HEO orbits; (2) lunar surface missions requiring survival through 354-hour lunar nights; (3) deep space science missions where solar power is impractical; and (4) backup power for critical satellite systems.
Who are Deep Space Energy’s competitors?
Main competitors include Zeno Power (US, $45M raised, NASA contracts), which is also developing Am-241 systems, and traditional RTG providers. The UK National Nuclear Laboratory and University of Leicester are developing similar technology for ESA. City Labs (US) provides lower-power tritium batteries for small satellites.
What is NATO DIANA?
The Defence Innovation Accelerator for the North Atlantic (DIANA) is a NATO programme that funds dual-use technologies with both defense and civilian applications. Deep Space Energy received funding from DIANA, validating the strategic importance of its technology for alliance space capabilities.
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