High-speed ammonia compressor for next-generation space cooling systems

As future space missions demand ever-increasing power and system complexity, thermal management becomes a key challenge. In the vacuum of space and in the thin atmospheres of the moon or mars heat can only be dissipated through radiation. This limits the achievable cooling capacity and directly ties performance to radiator size and temperature.

Current state-of-the-art solutions rely on mechanically pumped fluid loops (MPLs), which provide up to around 12 kW of cooling capacity. However, higher performance requires larger and heavier radiators, limiting scalability for advanced satellites and space stations.

To overcome these limitations, the use of heat pump cycles is gaining attention. By elevating the radiator temperature, the same thermal power can be rejected with a smaller radiator area. Building on this concept, Celeroton has developed and successfully tested a compact ammonia turbo compressor, forming the technological core of a novel space-qualified heat pump system.

Compact and efficient turbo compressor design

Conventional piston, screw, and scroll compressors common on earth are not suitable for space due to their weight, mechanical wear, and vibration levels. In contrast, radial compressors operating above 100,000 rpm offer superior efficiency, extremely low micro-vibrations and minimal mass in a minimal footprint.

To meet the strict reliability requirements of long-duration missions, the Celeroton turbo compressor is equipped with gas bearings, ensuring completely contact- and lubricant-free operation, ideal for ammonia as a working fluid. The absence of oil contamination improves long term system efficiency and supports maintenance-free operation over lifetimes exceeding 15 years.

From concept to reality: successful testing with ammonia

The ammonia compressor has been built, integrated, and tested in a dedicated test bench designed and built by Celeroton specifically for gaseous ammonia operation. The prototype compressor achieved the target pressure ratio of 2.27 at 20 kW of thermal power, demonstrating performance within the predicted aerodynamic range.

Measured loss data closely match Celeroton internal models, confirming the accuracy of Celeroton’s design and simulation approach. These results represent an important milestone toward space-qualified turbo compressors for heat pump applications.

Outlook

Celeroton’s successful demonstration validates the feasibility of lightweight, high-speed turbo compressors for next-generation space thermal management systems. Further optimization of rotor design, gas bearings, and surface finishing will continue to enhance efficiency and scalability.

For more technical details, refer to the full scientific publication on the ammonia heat pump compressor.

Contact us to explore how Celeroton’s high-speed turbo compressors can advance your next space mission.