Русско-английский идиоматический словарь по космонавтике - тормозная двигательная установка

Once the spacecraft has been oriented, the on-board electronic programming device sends a command to switch on the retro-engine…

…I switched on the retro-rocket unit, and the spacecraft obediently left the orbit and started moving towards the Earth.

The non-pressurized part of the compartment houses the liquid-rocket unit designed for orbital and reentry manoeuvres.