Angelantoni has been an active supplier in the aerospace Industry for over 20 years, as a producer and suppler of complete systems for environmental simulation testing. For example, Angelantoni space simulators are used to test components, subsystems, and complete satellites. The most common application of the space simulator are related to the testing of satellites in a thermal vacuum chamber, which involves the simultaneous control of two environmental parameters: Pressure and temperature.

Features and Benefits:

• Wide range of chamber sizes, with diameters ranging from under 1m up to 10m
• High quality and vast experience in vacuum pumping systems
• High quality of black shroud paint with a solution for low out gassing at maximum temperatures (>+150°C) according to ESA standard ECSS-Q-ST-70-02C
• Special attention to minimizing consumption through hardware solutions and software management of the plant
• Integrated control and monitoring system totally developed by ACS
• Special attention to and experience in redundancy aspects
• Full capability for supplying turnkey systems

Satellite Testing:

Thermal cycling: used to subject the DUT (Device Under Test) to the alternation of high and low temperatures within a temperature range that is typically -100°C to +100°C, while the pressure is maintained at values below 10^-6 mbar 9high vacuum). While the satellite is subjected to thermal cycling, it is possible for RF (radio frequency) signals to be exchanged across the chamber through dedicated wave-guides. These tests may take up to a month.

Thermal balance: made for the validation of the thermal mathematical model of the satellite. Test are performed by creating an environment with a temperature range similar to that which the satellite will encounter while in orbit) below -180°C). Some parts of the satellite are also subjected to heating from the hot sources) lamps or IR emitters) to simulate the effect of the sunrays which can cause temperatures to locally reach +150°C. The satellite is kept at a constant pressure of 10^-6 mbar during these tests.

A wide range of thermal systems is available based on different needs, economy and flexibility for example:

• Liquid nitrogen flooding (boiling mode)
• Liquid nitrogen flooding (boiling mode) with heating elements (lamps or IR emitters)
• Liquid nitrogen partial flooding (boiling mode) with heating elements (lamps or IR emitters)
• Liquid nitrogen pressurized circuit with heating elements (lamps or IT emitters)
• Pressurized gaseous nitrogen circuit
• Combined liquid and gaseous nitrogen modes
• Mechanical cooling with intermediate fluids

The vessel - produced from high-quality steel, is the external structure of the testing area and is capable of withstanding the pressure differences between the internal and external environments. Inside the chamber there is an enclosed area in which the tests are carried out. It consists of a cylindrical body, which, at one end, has a large door-shaped concave disc for accessing the objects to be tested. A cylindrical heat shield, the “shroud” is placed within the vessel. This permits adjusting the temperature inside the test area. The DUT is placed in the center of the test are to ensure proper radiation at the specified temperatures. Two disc-shaped heat shields close the two ends of the cylindrical body completely, so as to achieve a uniform temperature field around the specimen. The shroud consists of two laminated sheets with a space of a few millimeters between them. The space is used for the passage of the fluid heat carrier from the thermal power generation system.

The thermal system - is located near the room and consists of all components (pumps, valves, heat exchangers, sensors) necessary for changing the temperature of the fluid heat carrier. This system is connected to the shroud through super insulated pipes that pass through the walls of the vessel. The fluid heat carriers are typically liquid and gaseous nitrogen, but in some applications special oils can be used.

The vacuum generation plant - consists of a set of vacuum pumps, whose main function is to extract air from the chamber to obtain and maintain the vacuum. There are two stages of pumping: the first stage, called primary or rough pumping, allows the transition from ambient pressure to values of around 10^-2 mbar, necessary to trigger the operation of the second stage, consisting of more sophisticated pumps (cryogenic pumps) that allow the achievement of a high vacuum.

Typical levels of final pressure inside the chamber are around 1x10^-6 mbar, but can drop to values in the range of 10^-8 mbar.

The control and management system - of the space simulation chamber consists of a set of electrical cabinets for the power distribution and for the PLC-based control of the chamber subsystems.

The data acquisition system and the SW PC board provide the main user interface and the direct mans for controlling and monitoring the whole chamber.