ISS

4 min

The International Space Station is mankind's largest and longest lived space station to date. It pursues a wide variety of goals, such as observing space and searching for antimatter – and relies on Harmonic Drive® products to do so.

Research at an altitude of 400 kilometres

The research goals of the ISS are manyfold: it serves not only to explore the Earth itself, but also to observe space, conduct research in weightlessness and search for antimatter.
The ISS is the most expensive, non-military project that mankind has ever started. It is representative of peaceful, global cooperation between different cultures and nations.
The many modules of the ISS represent an outstanding mark of technological progress and demand the highest performance and absolute reliability from their components – including the Harmonic Drive® products used in various modules.

Extreme environmental conditions

While the ISS's room temperature is kept constant at around 22 °C, technical applications and components in the space station's external environment have to withstand harsh conditions. For example, the outer cladding of the ISS heats up to +120 °C where the sun's rays hit it. Shady sides, on the other hand, expect temperatures of up to -160 °C in some cases, under which technical equipment must work reliably.

Harmonic Drive® Gears support water circulation

Harmonic Drive® Gears have a remarkable track record in space applications and their mechanisms. Even though they have been successfully used in space missions for decades, the quest for further optimisation is a constant companion. In particular, environmental test data at component level for the gears of the precision gearbox as well as accompanying analyses play an elementary role. This is evident, for example, in the applications of Harmonic Drive® products in the environment of the International Space Station: In order to enable water circulation at an altitude of up to 460 kilometres, specially adapted gears from Harmonic Drive SE are used to control valves. The essential basis of the actuator is a stepper motor, which is characterised by a simple control principle.

In use for cartography and planetary exploration

Harmonic Drive SE has developed fully space-qualified gears for the Stereo Vision Measurement System (SVMS) of the ISS, which is used for cartography and planetary exploration in the outer ISS environment. For this purpose, a dual camera system was installed on a pan and tilt head to align the cameras with the objects to be observed. Based on Harmonic Drive SE's experience with high positioning accuracy and good synchronisation at low speeds, two Harmonic Drive® Gears are used to align the camera in pan and tilt direction. For both axes, gear mounting kits of the type HFUC-14 are used, which are made of stainless steel.

New challenges

The technologies and materials derived from the project specific requirements, such as special materials, extreme lightweight design or dry lubrication, are developed by a team of specialists for the respective aerospace applications and are manufactured in-house. Products of the Harmonic Drive® Gear Component Sets CPL-2A and CSD-2A often serve as a starting point, especially for the areas of space mechanisms, space robotics and space exploration. These are characterised by their compactness and reduced weight.

Essential for the use of these strain wave gears are their core properties, such as excellent transmission accuracy, high rigidity, zero backlash, high power density (torque-to-weight ratio) and the high single-stage reduction ratio.

To realise that people can live in space, I had to spend half a year up here. To realise how beautiful the Earth is, I needed a minute. To realise how fragile our little blue planet is, I needed only a moment.

The ISS in figures

The largest satellite in Earth orbit and the largest man made object in space: since 2 November 2000, the International Space Station has been permanently inhabited by space travellers. Every 93 minutes it orbits the Earth, our home planet, as do the various Harmonic Drive® products and applications.