The LUNA center in Cologne, operated jointly by the German Aerospace Center (DLR) and the European Space Agency (ESA), is unique in Europe. The up to 700‑square‑meter test facility is filled with special regolith‑like material that mimics lunar dust, allowing researchers to simulate lighting conditions and terrain for future missions. In June, the first Estonian lunar rover — the student‑built KuupKulgur — arrived for testing.

The road to Europe's space‑science hub was anything but easy. According to project lead and Tartu Observatory engineer Quazi Saimoon Islam, it is extremely difficult for a student project to gain access to the test center. "You can't just book time and show up. You need a project with ESA, and ESA must confirm to the center that the test is important and must be carried out," he explained.

The team has had to continually prove to European partners that Estonian developers are capable of building rovers. "In this field, experience, visibility and past success stories are often concentrated in larger spacefaring nations. For us, it means proving our capabilities step by step," Islam said.

Eventually, thanks to researchers at the University of Ljubljana and Estonian partner Taara Robotics, the team secured a chance to travel to LUNA. But even the trip to Germany was not without mishaps. "We left Tartu in our observatory's bus and had driven almost exactly a thousand kilometers when the bus started making a very suspicious noise on a Polish highway," recalled KuupKulgur software engineer and University of Tartu master's student Andres Aleksander Tammer.

At a repair shop in Poland, all six mechanics stopped work to inspect the Estonians' bus. "You know things are bad when the mechanics point and start laughing. It turned out the front axle was hopelessly broken," Tammer said. The team rented a car and packed it to the roof with space‑technology equipment.

Emotions on the artificial Moon

Upon arrival, the Estonian engineers were stunned by the conditions. Until now, KuupKulgur had been tested in a 64‑square‑meter sandbox filled with granite sand in Tõravere. LUNA, by contrast, is vastly larger, and its fine dust allows simulation of multi‑meter‑deep craters.

Lunar dust is as fine as volcanic ash and resembles asbestos, so the Estonian engineers had to wear protective suits. "Our biggest concern was whether the rover was dust‑proof enough so that dust wouldn't get into the motors or electronics," Islam said. Despite the short preparation time, the rover performed flawlessly during both eight‑hour test days.

"It was impressive to see the rover move without tipping over or stalling… I almost had tears in my eyes," Islam admitted. "It was a huge confirmation that our hard work has paid off."

Tammer described the experience simply: "It was just awesome. To be in a place where real European space technology is developed and to test our rover there."

A rover that stood out

Alongside KuupKulgur — which helped gather data for autonomous‑systems developer Taara Robotics — five rovers from the University of Ljubljana were also tested. According to the developers, KuupKulgur caught the attention of foreign colleagues.

"The entire mechanical frame is ours, the electronics are our design, and most of the software is now ours too — except for the onboard computer, which would be too complex for students to build," Tammer said. For example, the Estonian rover was the only one that could be conveniently charged via USB‑C.

The software also impressed. "The local IT specialist said he hadn't seen any other team configure their rover into the local network so quickly and flawlessly," Tammer noted. While other teams controlled their robots from behind a glass window, Islam sat at a computer elsewhere and operated KuupKulgur solely through its camera feed and a custom web application.

"We built KuupKulgur to be easy to use," Islam said. "We go to events where even children can drive it — it's that simple." Even ESA's renowned future‑robotics engineer William Carey became engrossed in controlling the rover.

"He gave us excellent advice on higher TRL (technology readiness level) requirements — what ESA would expect from a system. That's exactly what we need, because our goal is to meet those requirements," Islam said.

Creating a new standard

The main goal of the test mission was data collection — more than a terabyte was brought back to Estonia. LUNA uses about 25 specialized cameras that track markers on the rovers and record movement trajectories with millimeter precision. The same technology is used in filmmaking to capture actors' movements for visual effects. The recordings allow Estonian engineers to repeatedly test the rover virtually.

"If I want to test my localization algorithm and see how the rover moved, I can take the German data file, run it on my computer and replay it. The value of this dataset is enormous — we can test things in a new environment," Tammer explained. The tests gave the team confidence that the rover can handle even more Moon‑like conditions.

But the long‑term goal is not just building one robot. The Tartu Observatory team wants to create a rover standard similar to the CubeSat format that revolutionized space technology — hence the project name KuupKulgur (CubeRover).

Islam said the aim is to offer scientific instruments a "taxi ride" to the Moon: "If a developer has an instrument they want to send to the Moon and can fit it into a standard 10×10×10‑centimeter block, they attach it to our rover."

Rover technology is moving toward systems where one machine searches for minerals and another, equipped with a specialized robotic arm, collects them. In such a scenario, a standard platform that can accept different payloads becomes highly valuable.

When will we see an Estonian rover on the Moon?

Just three or four years ago, students were driving a 3D‑printed prototype around the observatory — something that looked like a toy. The development leap has been rapid. But when will an Estonian robot reach the Moon?

"That's a very good question — I'd like to know the answer myself," Tammer said. "Unlike satellites, we must reach not only Earth orbit but also lunar orbit and then actually land. Ideally we're talking five years, but ten years is a realistic number to say publicly."

Islam, cautious as a scientist, also sees the early 2030s as a target. Since Estonia does not build rockets or landers, much depends on geopolitics and commercial partners. Funding and belief in young engineers' ambitious ideas remain the biggest challenges.

"I've had to answer internationally why build yet another rover. My answer is always: if we don't try, we'll never achieve it," Islam said. He emphasized that the project is not just about building a rover but about training Estonia's future engineers and tech entrepreneurs. More than 20 bachelor's and master's theses have already been written on KuupKulgur.

"These students we're involving now are the ones who will create future technology — they may become the next Elon Musks. Our motto is 'Leave our mark.' We want to leave Estonia's footprint on the Moon," Islam said.

--

Follow ERR News on Facebook and X and never miss an update!