What you need to consider when planning your TVAC system?

Determining if a chamber is necessary defines the overall setup of the TVAC system. A chamber is crucial for creating a controlled environment to simulate the vacuum of space, which is essential for testing spacecraft components, satellites, and propulsion systems.

Knowing if a chamber is required helps in understanding the scale and complexity of the system needed.

When a chamber is required then we also need to understand:

• What material is to be used? The material choice affects the chamber's compatibility with different processes and its ability to withstand various conditions such as extreme temperatures and vacuum pressures. The choice of material will impact both performance and quality of the simulation environment.

• What is the desired chamber geometry: cylindrical or cube? The shape of the chamber impacts the distribution of thermal and vacuum conditions inside.
  Cylindrical chambers are often preferred for their uniform stress distribution and ease of manufacturing, making them suitable for testing long, slender objects like thrusters.
  Cubic chambers might be chosen for specific testing configurations or spatial constraints as well as testing large, flat components or multiple small satellites simultaneously.

• What would be the chamber dimension/footprint? Accurate dimensions of the chamber ensure it can accommodate the test objects and fit within the designated lab space. The dimensions also affect the volume and, consequently, the vacuum pump requirements and the overall system design.

Understanding the specific application and process allows for the customization of the TVAC system to meet unique requirements. This includes knowing what the system will be used for? satellite component testing, material outgassing studies, or thermal cycling tests? For space technology manufacturers: testing for outgassing, thermal cycling, and operational readiness of components?

Gathering detailed information about your process and application helps us design a system that meets your specific needs. This ensures that all necessary features are included, such as thermal shrouds for uniform temperature distribution or special fixtures for holding CubeSats during vibration testing.

The size, material, and number of parts of the device under test s also important to undertand as it will influence the internal configuration of the chamber, including the arrangement of thermal shrouds, platens, and fixtures. It also affects the thermal load and vacuum pumping requirements.

Specifying internal features like platens and shrouds ensures the vacuum chamber can support the device under test and provide the necessary thermal management.

These features are critical for achieving uniform temperature distribution and accommodating different test setups, such as rotating platforms for 360°C exposure or fixtures for holding components at specific orientations.

Feedthroughs allow electrical, thermal, and mechanical connections to pass into the vacuum chamber without breaking the vacuum seal.

Knowing the number and types of feedthroughs needed helps in planning the chamber's ports and ensuring compatibility with external equipment, such as power supplies, sensors, and data acquisition systems used in space technology testing.

Accessories are essential for the operation and functionality of the TVAC system. They allow for controlled evacuation and venting, connection of different components, and observation of tests in progress.

For space simulation, high-quality accessories are needed to maintain the integrity of the vacuum and thermal environment.

• Valves are used to control the flow of gases in/out of the chamber. Different types of valves and their placement are critical for efficient operation and safety of the vacuum system. In space simulation, precise control over gas flow is needed to replicate different atmospheric conditions.
• Flanges provide the connection points for various components of the vacuum system. The number, types and sizes needed depend on the specific equipment and accessories being used. For space technology, robust flanges are required to ensure a tight vacuum seal under extreme conditions.
• Viewports allow visual monitoring of the tests inside the chamber. They are chosen based on the need for observation, camera placement, and lighting requirements. High-quality viewports are essential for capturing detailed images and videos of tests, critical for analyzing the performance of space components.

Defining the heating and cooling requirements ensures that the chamber can achieve and maintain the desired temperature ranges. This is crucial for simulating the thermal conditions of space, where temperatures can vary widely, and conducting accurate thermal cycling tests to assess the durability of spacecraft components.

• The temperature range that needs to be achieved within the chamber dictates the type of heating and cooling systems required.  For space simulation, the system must handle extreme temperatures, replicating conditions from deep space cold to solar heating, to ensure components can withstand the harsh environment.
• The choice of cooling system affects the chamber's ability to reach and maintain low temperatures. Cooling systems are crucial for simulating the cold vacuum of space and testing the thermal response of materials and components used in spacecraft and satellites.
• The heating system must be capable of achieving the desired temperature uniformity and stability. Heating is essential for simulating solar radiation and conducting thermal cycling tests, which are important for evaluating the performance of spacecraft thermal protection systems.

Different gases have varying properties that affect their pumping and handling requirements. Knowing which gases will be used helps select appropriate vacuum pumps and ensure safety measures are in place.

For space simulation, this may include pumping residual air, outgassing products, or specific test gases.

The required vacuum range determines the type and number of vacuum pumps needed.

Different applications may require high, ultra-high, or extreme vacuum levels, each with specific equipment and operational considerations.

The time required to reach the desired vacuum level impacts the design and capacity of the pumping system.

A shorter time limit may need more powerful pumps or additional pumping stages. Fast pump-down times are essential for high-throughput testing environments, such as production lines for small satellites.

Selecting the right vacuum pumps is essential for achieving the required vacuum levels efficiently. Different types of pumps offer varying benefits and should be chosen based on the specific application.

For space simulation, a combination of these pumps may be used to achieve and maintain UHV conditions.

• Primary/Roughing pumps: The choice between wet and dry roughing pumps affects maintenance, cost, and contamination risks.
• Turbomolecular pumps: mechanical bearing or maglev? Mechanical bearing turbopumps are less expensive but require more maintenance. Maglev turbopumps offer higher reliability and lower vibration, making them suitable for sensitive applications.
• Cryopumps provide very low temperatures for capturing gases and achieving ultra-high vacuum levels. Essential for applications requiring extremely low pressures and minimal contamination.
• Ion pumps and Non-Evaporable Getter (NEG) pumps are used to maintain ultra-high vacuum conditions. They have different operating principles and suitability depending on the specific vacuum requirements and gases to be pumped.

Vacuum gauges are necessary for monitoring pressure levels within the chamber. The types and number of gauges needed depend on the range of pressures to be measured, from rough vacuum to ultra-high vacuum.

Accurate pressure measurement is crucial for ensuring the reliability of space simulation tests.

Automation and control systems enhance operational efficiency by allowing precise control of vacuum levels, temperatures, and other parameters.

They also improve safety and repeatability of tests. For space simulation, automated systems can manage complex test sequences, data acquisition, and real-time monitoring.

Defining power requirements ensures the system is compatible with the available power supply. Space simulation tests often require stable and uninterrupted power to maintain test conditions over extended periods.

• The choice between single-phase and three-phase power affects the electrical design and the type of equipment used. 
• The operating voltage must match the local power infrastructure, and the specifications of the equipment used.
• Any limitations on power availability or usage should be specified to ensure the system operates within safe and efficient parameters.

A load lock allows samples to be introduced and removed without venting the main chamber, maintaining vacuum conditions and improving throughput.

This is particularly useful in production environments or when multiple tests are conducted in succession.

Specifying communication protocols ensures compatibility with existing systems and facilitates data transfer and remote control.

This is essential for integrating the TVAC system with other test equipment and for monitoring and controlling tests from a central location.

The operating environment affects the design and materials of the system. Considerations include temperature variations, humidity, and exposure to corrosive elements.

Ensuring the system can operate reliably under these conditions is crucial for maintaining test accuracy and equipment longevity.

Mobility options determine how the equipment can be used and moved within the facility. This flexibility is important for optimizing lab space and for conducting tests in different locations as needed.

• Frame-mounted systems are typically fixed installations, providing stability and robustness for larger or more complex setups. They are suitable for long-term, high-precision tests where minimal vibration and maximum stability are required.
• Cart-mounted systems offer flexibility and ease of movement, making them suitable for applications requiring frequent relocation or space-saving solutions. This is ideal for dynamic test environments where different setups are needed for various components.

Understanding service limitations and desired maintenance intervals helps in planning the upkeep of the system, ensuring reliability and longevity.

Regular maintenance is crucial for preventing downtime and ensuring the system remains in optimal working condition.