Thermal insulation
& cable channel systems

Based in Cannes La Bocca, just a stone's throw from the Thales Alenia Space site, Soditech is an SME with around 60 employees founded in 1990 by Maurice Caillé, who has now handed over the reins to his daughter, Madenn Caillé. The company specialises in the design and integration of mechanical, thermal and electrical sub-assemblies.

In terms of space mechanics, the activity mainly covers the assembly of components on a satellite flight panel. In particular, Soditech glues inserts, heat pipes and probes to panels. The company also assembles mechanical bays. In the thermal sector, the company designs and manufactures MLI (Multi Layers Insulation), which is insulation used to reduce heat radiation losses. A third area is electrical, with the design and manufacture of space harnesses, the system for electrical cables used to supply power to the various items of equipment on a satellite.

MLI and space harnesses

MLIs and space harnesses are the company's two flagship products. MLIs are multi-layer thermal insulators, alternating a material that acts as a radiative screen (i.e. the screen prevents radiation from passing through the insulation) with layers that limit conduction and convection between the radiative screens. This type of thermal insulation is rarely used outside the space industry. While it works very well for radiation, it works much less well for convection¹. However, as convection does not occur in space because it is in a vacuum, this type of insulation is particularly well suited to this environment. These are the MLIs whose outer sheet is generally made of Kapton, a golden polyimide film (polyimide is a polymer known for its thermostability). It is these MLIs that give satellites the appearance of being covered in gold leaf.

Space harnesses are used to supply power to the various items of equipment on satellites. They are made up of tens of thousands of cables and their manufacture is highly complex. Charlène Di Campo, Director of Operations at Soditech, explains the four main stages in their manufacture: “We start by making what we call the starter connector and by making one end of each of the cables. Once these ends are complete, we route the cables in their entirety on 1:1 scale models. Once this is done, we finish off with the second end of the cables. Then comes the final stage, during which the whole assembly is checked, tested and then sent to the customer for integration.”

Small but mighty...

If Soditech has been able to win over the sector's major manufacturers, particularly with its MLIs and space harnesses, it is largely because it offers them a global package capable of meeting their needs in their entirety. Soditech is able to take charge of an entire project, from the conception and design phase through to integration of the equipment on the satellite. According to Charlène Di Campo: “The advantage of mastering the entire process is that we are fully aware of all the manufacturing constraints. When a company is only involved in design, it often happens that certain elements cannot be industrialised. Another advantage is that we can travel to the customer's site to integrate our own equipment.” The company's close proximity to the Thales Alenia Space site at Cannes La Bocca is also an undeniable advantage.

Paradoxically, Soditech also draws its strength from its relatively modest size. The fact that it is a family-run SME makes it particularly agile and enables it to offer flexibility to its customers. It is therefore able to respond very quickly to their needs and adapt to them. This flexibility can be much harder to achieve for a large group. Conversely, an SME specialising in one area of activity often finds it more difficult to respond to global needs. Soditech has managed to get round this difficulty to some extent by integrating well into the local and national network. This enables it to find partners on its own scale who are complementary and specialise in other fields. This enables it to offer a more comprehensive range of services to its customers, who are generally major contractors.

For its various activities, the company has installed high-performance equipment that enables it to meet the many constraints involved in manufacturing components that will be used in space. These include an ISO 8-certified clean room covering almost 1,000 m2, in which a very small number of particles can be deposited on the top-of-the-range equipment it manufactures for the space, defence and research industries.

The company's premises also contain another ISO 5-certified clean room, measuring 25 m2, with an even more restricted environment, where even fewer particles and unwanted molecules are recorded. This room is particularly useful for integrating and cleaning equipment. In addition to its cleanrooms, Soditech has a wide range of tools for the automated manufacture and testing of its various harnesses and MLIs.

All this equipment enables the company to manufacture reliable products that can withstand the many tests they face during launch and their stay in space. During the launch of the satellite, all the equipment is subjected to very high temperature and mechanical stress due to the strong vibrations it has to withstand. Once in orbit, they have to withstand all the constraints associated with the space environment, in terms of radiation, cleanliness and outgassing.

Diversifying to offset the cyclical nature of the space industry

Since its creation 35 years ago, the company has developed well. In 2024, Soditech generated sales of €5.6 million, two-thirds of which in the space sector. In addition to Thales Alenia Space, its customers include all the major prime contractors in this sector, such as Airbus Defence & Space, CNES and ESA. What's more, in the space sector, Soditech works not only for satellite equipment manufacturers, but also for launch vehicle manufacturers. Today, even though it faces stiff international competition, its ambition is to keep pace with this fast-growing sector over the coming years. To date, the company has gone beyond the stage of manufacturing prototype equipment and delivering every 2 years. It now mass-produces for a number of companies around the world.

However, orders in the Space sector remain cyclical and somewhat unpredictable. To compensate for this, Soditech has sought to diversify into other activities, notably Research and Defence. This diversification is set to intensify over the next few years but is already bearing fruit. Its customers include a large number of French laboratories and several defence companies.

In the space sector, Soditech is also seeking to diversify its customer base and is not limiting itself to France. In fact, when we visited the company's premises, its current CEO, Madenn Caillé, was in the United States on a business trip...

1. Convection is all the internal vertical or horizontal movements that drive a fluid, involving the transport of the properties of the particles in the fluid as it moves. It can be due to temperature differences, mechanical agitation, pumping, etc. There is no air in space. Heat is therefore exchanged solely by radiation and not by radiation, convection and conduction as on Earth.