Precision for the Journey into Space – Carl Hirschmann’s Plain Bearing Technology in Use at ArianeGroup
Image credit: © ESA-CNES-ARIANESPACE-ARIANEGROUP Optique Vidéo du CSG – JM GUILLON
The company’s plain bearing technology is used, among other things, in satellite components and in the European Ariane 6 launch vehicle. These components must withstand extreme conditions—from cryogenic temperatures to high accelerations during rocket launch and the vacuum of space.
Long-standing Partnership in Space Exploration
The collaboration between Carl Hirschmann and ArianeGroup dates back more than a quarter-century.
Carl Hirschmann’s spherical bearings and spherical heads have been used in various space systems for decades. These components enable precise movements within mechanical structures while ensuring reliable load-bearing capacity.
With the new European launch vehicle Ariane 6, this proven technology has also been integrated into the current generation of European spaceflight. The maiden flight of Ariane 6 took place on July 9, 2024. Even prior to that, components featuring Carl Hirschmann plain bearing technology had been used in extensive test campaigns.
Use in the Ariane 6 Upper Stage
In the Ariane 6, Carl Hirschmann plain bearings are integrated into several structural assemblies, including the carrier platform for avionics components in the upper stage.
Image credit: Screenshot YouTube Flight VA267 | Amazon Leo LE-01 | Ariane 6 | Arianespace
Caption: Ariane 6 upper stage
Within this structure, the plain bearings ensure reliable mechanical connections and motion guidance.
In addition, Carl Hirschmann spherical bearings are used in the helium tank support structure, where they are integrated into the design via CFRP fasteners.
Image credit: Screenshot from YouTube Flight VA267 | Amazon Leo LE-01 | Ariane 6 | Arianespace
Caption: Helium Tank Support Structure | Carl Hirschmann plain bearing technology integrated into CFRP fasteners
Before the Ariane 6 completed its first flight, the relevant assemblies were tested in various test modules. These include, among others, the Combined Test Module (CTM) for integrated system tests and the Hot-Fire Module (HFM) for engine tests under real operating conditions.
Image credit: ©2024 ESA-CNES-ARIANESPACE-ARIANEGROUP / Optique Vidéo du CSG – S MARTIN
Extreme Stresses During Rocket Launch
The demands placed on mechanical components in spaceflight are exceptionally high. During launch, enormous dynamic and static forces act on the rocket’s structure and the assemblies integrated within it.
The avionics structure and the payload are subjected to severe vibrations, acoustic stresses, and accelerations. Peak accelerations of up to 6 g can occur during launch.
Added to this are other stresses such as:
- Impact forces during stage separation
- aerodynamic forces on the structure
- dynamic loads during flight
Once the Ariane 6 upper stage has ignited and the rocket leaves Earth’s atmosphere, the rocket and payload are completely immersed in the vacuum of space.
Temperature, Vacuum, and Radiation
In addition to mechanical stresses, the components used must also withstand extreme environmental conditions.
A key factor is cryogenic temperatures, which can result from the use of typical rocket propellants such as liquid hydrogen and oxygen. Components in the vicinity of these systems are thus exposed to extremely low temperatures.
Once in space, additional factors come into play. These include, among others:
- the complete vacuum of space
- severe temperature fluctuations
- direct solar radiation on structural components
For example, in the area of the helium tanks after stage separation, the ball joints installed there are directly exposed to solar radiation.
Custom Solutions for Space Applications
For applications in the Ariane rocket family, Carl Hirschmann supplies exclusively custom-designed parts. The spherical bearings and spherical heads used feature specially developed geometries and customized coatings.
These designs are precisely tailored to the respective mechanical and thermal requirements. In addition to load-bearing capacity and precision, the assembly environment also plays an important role.
For example, the components are integrated during the assembly of the Ariane 6 upper stage in cleanrooms at the Bremen facility. In these controlled environments, all components must be free of particles and contaminants to prevent malfunctions or damage to sensitive electronics during subsequent operation.
Reliable Technology for Demanding Applications
Carl Hirschmann’s plain bearing technology has proven itself in aerospace projects over many years. Previous deliveries for applications in the Ariane rocket family demonstrate high operational reliability and meet the stringent requirements of the aerospace industry.
In addition to product quality, technical collaboration is also a key component of this long-standing partnership. Carl Hirschmann supports development and integration processes with technical expertise and develops solutions that are precisely tailored to the respective applications.
Prospects for Future Space Projects
Future launch systems will continue to require high-precision mechanical components. As demands for efficiency, weight, and load-bearing capacity increase, specialized fasteners are becoming increasingly important.
The experience gained from more than two decades of space applications provides a solid foundation for further developments and potential future projects within the European space program.
About ArianeGroup
ArianeGroup is an industrial group that carries out missions to safeguard sovereignty in the fields of space and defense. With more than 8,700 highly qualified employees in France and Germany, ArianeGroup possesses unique expertise in access to space. The company’s expertise covers the entire spectrum of civil and military launch vehicle systems, from design, development, manufacturing, integration, flight preparation, and maintenance through to decommissioning. ArianeGroup is the prime contractor for ESA on the European Ariane 6 launch vehicle and for the French Defense Procurement Agency (DGA) on the M51 strategic ballistic missile for France’s oceanic deterrent forces.
As a globally recognized specialist in innovative and competitive solutions, ArianeGroup masters the most advanced technologies and applications, ranging from propellant chemistry and composite materials to liquid, solid, and electric propulsion systems for space applications. In addition, ArianeGroup—both directly and through its subsidiaries Sodern, Pyroalliance, Nuclétudes, and APP—offers a wide range of equipment and services for the space, defense, and industrial sectors.
In the launch vehicle sector, the Group markets and operates the Ariane 6 and Vega-C launch vehicles—developed for ESA—through its subsidiary Arianespace. Its subsidiary MaiaSpace develops and markets the reusable Maia launch vehicle.
ArianeGroup is a joint venture between Airbus and Safran, in which both hold a 50 percent stake. The Group’s consolidated revenue in 2025 amounted to 2.6 billion euros.
Image credit: ©2024 ESA-CNES-ARIANESPACE/OPTIQUE VIDÉO DU CSG / S MARTIN – P PIRON