Thermal Vacuum Assemblies for Space Applications

In general, space engineered components have to meet strict requirements regarding qualification and measuring/testing. Whole satellites or space components are tested in thermal vacuum chambers to simulate conditions found in space. They are exposed to vacuum and temperature variations from extremely cold to extremely hot. The devices under test are connected to the measuring instruments outside the chamber using special RF assemblies. Figure 1 shows a thermal vacuum chamber.

Simulating the conditions found in space places extreme demands on all components, from the test subject inside the thermal vacuum chamber through to the measuring installations outside. To address these issues, HUBER+SUHNER has developed SUCOFLEX® TVAC (thermal vacuum) assemblies for vacuum chamber applications, which ensure that the test data arrives perfectly at the measuring instruments.

Figure 1

Figure 1 Thermal vacuum chamber.

Figure 2

Figure 2 Connector with venting hole.

A specific requirement is that the assemblies used within the vacuum chamber must meet the outgassing standard set out, e.g. by the European Space Agency (ESA) within ECSS-Q-ST-70-02 C, to prevent contamination of the chamber or equipment with solvents evaporating from certain materials.

To protect the assemblies from stress and to provide extended life, the TVAC connector contains venting holes for easy air flow into and out of the components during the pressurization/depressurization cycles. The venting holes are shown in Figure 2.

Matched Components

Especially in such demanding environments, it is important that the complete run of cables and connectors be perfectly matched, which makes SUCOFLEX cables, with their excellent mechanical properties, a good solution for TVAC applications. Also, the SUCOFLEX TVAC venting holes offer the right compromise between smooth air flow and good shielding, while defined evacuation paths in the components allow the pressure changes to be balanced quickly, resulting in less stress.

Thanks to the robust design, the electrical performance is very good. All materials used comply with ESA’s ECSS-Q-ST-70-02 C standard and have been approved by an independent test lab. The TVAC portfolio comprises assemblies using SUCOFLEX 103, 104, 404 and 106 cables, covering all kinds of applications, including low and high power/frequencies, and with or without armour.

Table 1

Increasing Requirements

Especially developed to address the market trend towards higher frequencies and greater bandwidth, Huber+Suhner has developed and qualified the new SUCOFLEX TVAC SK connector (2.92 mm) that operates up to 33 GHz. Together with the SUCOFLEX 103E cable (available with or without armour), the company guarantees the best-in-class performance with this configuration and excellent long-term behaviour. The technical data for these assemblies is provided in Table 1.

The SUCOFLEX TVAC assemblies and adaptors have been developed to enable customers to perform measurements to the highest industry and space standards and a summary of the products’ key features and benefits are shown in Table 2.

Table 2

For applications outside thethermal vacuum chamber, Huber+Suhner also offers a wide variety of high-quality SUCOFLEX assemblies for space applications that are not subject to outgassing restrictions. Also, as a result of its longstanding collaboration with leading satellite manufacturers and test institutions, the company has gained extensive experience in this field and can design customer-specific solutions and cable assemblies on request and under clean room conditions (DIN ISO 14644-1 class ISO 5).

The new Huber+Suhner TVAC product portfolio provides optimal coverage for the commonly used frequency bands L, S, C, X and K (up to 33 GHz) relevant in the space sector, and are characterised by their extra high level of robustness and reliability. All assemblies have been designed and tested for use in the temperature range from -30° to +80°C but higher temperature requirements can be met.

Huber+Suhner AG,
Herisau, Switzerland
+41 71 353 4111,,