Latvian nuclear power startup Deep Space Energy (DSE) has secured €930,000 ($1.1m) to develop a radioisotope power generation system, which could allow Moon missions to last multiple years. The funding includes a €350,000 pre-seed funding round, and €580,000 in public contracts and grants from the European Space Agency (ESA), NATO’s Defense Innovation Accelerator for the North Atlantic (DIANA), and the Latvian government. DSE is the first Latvian company ever selected for the NATO DIANA programme. The pre-seed round was led by Outlast Fund and Linas Sargautis, co-founder of the Lithuanian space startup NanoAvionics (now Kongsberg NanoAvionics).
DSE, founded in 2022, has already validated its technology in lab conditions. The company will use the new funds to continue its R&D, and expand its team to include systems engineers, who can help translate the power generation system into a subsystem on future spacecraft.
The company is developing a Radioisotope Thermo-Acoustic Linear Induction Generator (RTALIG) that converts heat from the natural decay of radioisotopes into electricity. Unlike traditional Radioisotope Thermoelectric Generators (RTGs) which use solid-state thermocouples, DSE’s system utilises a Stirling engine and dynamic converter to achieve significantly higher conversion efficiency.
While the Stirling engine is typically seen as less reliable for spaceflight, due to its complexity and moving pistons, DSE has built a version that relies on just one piston to decrease the risk of failure. The result is a system that is four to five times more efficient than RTGs, while keeping the reliability needed for long-term spaceflight.
The system requires approximately 2kg of Americium-241 to generate 50W of power, compared with the 10kg required by legacy RTG systems for the same output. The RTALIG design targets 25% efficiency, roughly five times the efficiency of traditional thermoelectric systems.
“Very simply, we need five times less radioisotope fuel compared with electric generators, and this is actually the game changer,” CEO Mihailis Ščepanskis told Payload. “As we speak right now, there is no reliable and scalable supply of radioisotope material.”
The company’s goal is to create a system with two uses cases: extending the lifespans of lunar rover missions to support agency efforts on the Moon in the short term, and commercial applications, including resource prospecting and lunar mining, in the long term; and flying on board satellites in orbit to provide a strategic power reserve to decrease satellite operators’ reliance on redundant hardware in orbit.
DSE is targeting a demonstration flight in 2029, most probably with an electric emulator on board instead of radioisotopes. This is a strategy to earn flight heritage without having to wait for regulatory approval to fly nuclear materials in space. From there the company expects to fly operational missions beginning in the early 2030s, depending on institutional demand and regulatory approval.
In the long term, DSE is positioning its technology to support the emerging lunar economy, including NASA and ESA’s Artemis and Argonaut programmes. A primary challenge for lunar exploration is the 14-day lunar night, where temperatures drop below minus 150 degrees Celsius, rendering solar-powered rovers inoperable.
By providing a heat and power source independent of the sun, DSE’s generators would allow rovers to survive multiple day-night cycles, potentially extending mission lifetimes from weeks to years. CEO Mihails Ščepanskis noted that reducing the fuel requirement is a critical factor, as global production of Americium-241 remains highly limited.
DSA has established a strategic roadmap focused on both orbital and lunar applications:
2026-2027: Technical maturation and development of a secure supply chain for raw materials.
2029: Planned demonstration flight, likely utilising an electric emulator to earn flight heritage.
Early 2030s: Deployment of operational units as auxiliary power for high-value satellites in Medium Earth Orbit, Geostationary Earth Orbit and Highly Elliptical Orbit.
2035 Horizon: Scaling production to support a fleet of small rovers and permanent infrastructure on the lunar surface.
“The availability of future services and the scale of industrial activity on the Moon are directly linked to the availability and price of energy,” explained Ščepanskis. “By quintupling the amount of electricity generated per kilogram of radioisotope, we effectively reduce the cost per kilowatt-hour on the Moon. This means that all activities on its surface are more accessible. As a result, the volume of such activities will increase, along with demand for energy.”
He is convinced that Deep Space Energy represents Latvia’s opportunity to secure a foothold in the Moon economy, “By the middle of the century, the Moon economy will be roughly equivalent to Poland’s GDP. And we can be part of it. That means that Deep Space Energy’s operations on the Moon could double Latvia’s GDP. But that will be mid-century. For now, our technology can help Europe address an equally important challenge in the form of security.”
He noted that modern warfare is based on satellite-provided intelligence data. “Unfortunately, the lack of military satellites is the most serious gap in Europe’s defence. We rely on US data because the US has such satellites. Recent events show that greater independence – even from allies – and the development of sovereign assets in strategically important areas are vitally important. Military satellites, especially expensive geostationary ones, are a specific area in which Europe must invest resources.”
The resilience of expensive military satellites against potential enemy interference is crucial for ensuring secure access to intelligence data. Therefore, one of the challenges in the latest call of NATO DIANA is specifically dedicated to the resilience of space assets. Ščepanskis is particularly proud of DSE’s acceptance into the programme.
“NATO member states do not have armies that are as big as those of some other countries, so NATO is investing in ensuring that the alliance’s technological excellence is superior to that of its adversaries. NATO selected us, because it believes that our technology has the potential to contribute to the alliance’s technological superiority. The DIANA space challenge group includes several UK and US companies, as well as firms from Sweden and Portugal. It is already a major achievement that a Latvian startup has succeeded in joining this group, which has historically been dominated by major powers.”
Although DSE’s short-term strategy lies in the defence market, Ščepanskis believes that in the long term, the company will be among the participants in the Moon economy.
