There is a long standing dispute whether winged landing or vertical rocket powered landing is more efficient and overall better for reusable rockets on earth. 🙂
Powered landing can be looked at in a broad overview. The post documents what I doodled in my notebook some day in the summer.


Deceleration from terminal velocity to hover usually requires about 5-10% of total landed mass as propellants. The amount is directly proportional to the vehicle’s terminal velocity. Also, the higher acceleration, the better. The powered landing penalty fraction is N_{penalty}=\frac{2g}{3a}, so landing at 2 gee acceleration (3 gee felt) gives a penalty of 0.3. The required delta vee is \Delta v = v_{ter} (1+N_{penalty} ) where v_ter is terminal velocity. And the required impulse I=m \Delta v and propellant mass m_{prop}=I/v_{ex}.


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