General Features

The complete range of vacuum test chambers developed by ACS can be divided into two categories:

• Altitude chambers reaching depression levels of 100 Pascal (1 mbar)
• Space simulators which, artificially reproduce the real working conditions of satellites and spacecraft equipment, need to reach pressure values down to 10-8 mbar

Features

Altitude chambers:

• Thermoregulation system of the chamber's walls ensuring the uniformity of values below 200 mbar.
• Fall time from ambient pressure down to 1 mbar: 30 minutes
• Pressure regulation by means of a digital vacuum-meter
• Temperature range: from -70°C to +180°C

Space simulator:

• Cryogenic-pump and turbo molecular-pump system for the generation of depression values down to 10-8 mbar
• Pressure value stabilisation in the 10-3/10-7 mbar range
• Programmed pressure cycles
• Partial pressure control for 6 different types of gases
• Temperature range from -180°C to +180°C obtained by means of advanced- technology thermo-regulation systems for aerospace applications.

ISRO (India) space simulator

ACS space simulator delivered to the ISRO Satellite Centre in Bangalore, names HVT400MC, is one of the two largest space simulators existing in Asia and the most technologically advanced in the world. The simulator consists in a stainless steel structure that encases the area in which the tests are conducted a cylindrically shaped chamber 7m in diameter and 11m long. The system is fitted with 4 cryogenic pumps that generate the high vacuum required with a pumping capacity of 60,000 L/sec each.

Temperatures inside the cryogenic pumps drop to 10° Kelvin corresponding to -263°C through the use of helium, while the vacuum value reached is 10 -7 mbar. The thermal system includes 15 independent circuits capable of reproducing the conditions that surround satellites when in space. The circuits gradually reproduce the entire range of temperatures experience in space, from those on the side that is lit by the sun to those on the dark side, namely from -180°C to +180°C. Cooling is provided by liquid nitrogen stored in 4 large containers (22 meters tall) that can stock up to 500,000 litres of nitrogen.

The space simulator is run and supervised by a control and management system consisting of an array of over 40 electric panels for the distribution of power and for the control of the systems PLC logic, data acquisition racks (almost 800 temperatures) SW for overall system monitoring, topped by synoptics and redundant systems. All of this is distributed over a control console consisting of 5 PCs as well as another 12 stations distributed on two floors and interconnected via intranet. The system also allows for data exchange via optic fibre cable with the satellites control system.