Thermal vacuum testing is a type of test that verifies the performance and functionality of spacecraft and its components under vacuum and specific temperature conditions. It consists of cold soak, hot soak, and temperature variation processes. The environmental conditions are as follows: the vacuum degree is better than 6.5×10?3 Pa; there is a cold black background, with a hemispherical normal emissivity greater than 0.90. During the simulation test, the test piece is mostly in the working state, and its working parameters and environmental parameters are measured. Cold soak involves placing the spacecraft and its components at the specified lowest test temperature and holding it for a specified period of time; hot soak involves placing it at the specified highest test temperature and holding it for a specified period of time. Starting from room temperature, it is cooled down to the specified lowest test temperature for cold soak, then heated up to the specified highest test temperature for hot soak, and finally returned to room temperature, forming a temperature cycle.

Spacecraft Thermal Vacuum Testing
I. Test Preparation
Test Equipment: Thermal Vacuum Chamber
Equipment Model: HYOV Series
Equipment Manufacturer: HuanYi Instruments
Test Standard: GB/T 34522-2017 Method for Thermal Vacuum Testing of Spacecraft
II. Test Start-up Procedure
Set the working state of the spacecraft;
Start the vacuum measuring device, data acquisition system, and contamination measuring device;
Start the vacuum system to evacuate the air;
If necessary, conduct low-pressure discharge and micro-discharge detection;
Start the low-temperature system for cooling.
III. Test Operation Procedure
By adjusting the independent temperature control device, infrared heater power, contact electric heater power, and the working mode of the spacecraft, the components of the spacecraft are brought to the specified temperature;
Measure the temperature and other performance parameters regularly;
When the conditions for starting electrical performance and functional testing at the high and low temperature ends are met, conduct electrical performance and functional testing on the spacecraft according to the spacecraft test requirements;
When the cumulative duration of hot (cold) soak in the thermal cycle is reached, temperature reduction (increase) can only begin after confirmation by all participating parties;
Items “1” to “4” represent the test procedure for half a cycle. The subsequent thermal cycle procedure repeats items 1 to 4 until the cycle is completed.