When cosmonauts fly around the Moon in a circular orbit at an altitude of 50 km, how much do they need to increase the speed

When cosmonauts fly around the Moon in a circular orbit at an altitude of 50 km, how much do they need to increase the speed of the interplanetary spacecraft with their engines in order to direct it towards landing on Earth?

The speed in the circumlunar orbit is 1.69, and the parabolic one is 2.38 km / s, i.e. 0.69 km / s must be added.

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