Originally Posted by

**BruceTheHoon**
2) A rocket (initial mass **m**) is approaching a celestial body without an atmosphere (mass **M**, gravitational acceleration at surface **g**) with initial velocity **v** It then starts decelerating with a constant force **F**, so that it completely decelerates just a moment before touching the surface of the aforementioned celestial body.

What is the total volume of fuel used at this maneuver, if volume flow of fuel to the engines is **C**, while the engines are turned on?

First order approximation will suffice. For now.