At the Baikonur Cosmodrome, another stage of preparation for the "Progress MS-35" cargo spacecraft has begun before its dispatch to the International Space Station (ISS). The apparatus was delivered to a vacuum chamber, where it will undergo leak testing for approximately five days under conditions as close as possible to outer space. This was reported by RKK "Energia".
The tests are conducted using a vacuum unit equipped with turbomolecular and cryogenic pumps.
The former create a deep vacuum due to high-speed rotation of blades that transmit momentum to gas molecules, while the latter remove residual gases by depositing them on surfaces cooled to minus 196 degrees Celsius. Such a complex allows reducing the pressure in the chamber to less than 10⁻⁶ mm Hg.
To control the tightness of the spacecraft's compartments and pipelines, specialists use a helium-air mixture, which helps detect even minor leaks before the apparatus is sent into orbit.
Such a check is a mandatory stage in preparing any spacecraft for flight. The slightest leak in a vacuum can create problems, as air will begin to escape from the compartments, and it is much more difficult to fix this in orbit than on Earth. Therefore, specialists aim to identify all leaks in advance at Baikonur, simulating conditions as similar as possible to space.