2 added 1 character in body
source | link

As noted, the advantage to doing a higher thrust burn is that it takes less time and therefore uses less fuel.

The main advantage to a slower final approach is that it gives more time for the guidance system to correct the rocket's trajectory. Any guided landing procedure involves a cycle of estimating the accuracy of the current trajectory and steering to correct the error, and the more time allowed to make corrections, the better.

SpaceX seems to have settled on using one engine for the very last part of the landing even on three-engine approaches; for symmetry reasons this more or less eliminates the possibility of a two-engine landingapproach, because you'd have to change over from two outboard engines to the center engine in a fraction of a second, and engine start times are slightly variable.

As noted, the advantage to doing a higher thrust burn is that it takes less time and therefore uses less fuel.

The main advantage to a slower final approach is that it gives more time for the guidance system to correct the rocket's trajectory. Any guided landing procedure involves a cycle of estimating the accuracy of the current trajectory and steering to correct the error, and the more time allowed to make corrections, the better.

SpaceX seems to have settled on using one engine for the very last part of the landing even on three-engine approaches; for symmetry reasons this more or less eliminates the possibility of a two-engine landing, because you'd have to change over from two outboard engines to the center engine in a fraction of a second, and engine start times are slightly variable.

As noted, the advantage to doing a higher thrust burn is that it takes less time and therefore uses less fuel.

The main advantage to a slower final approach is that it gives more time for the guidance system to correct the rocket's trajectory. Any guided landing procedure involves a cycle of estimating the accuracy of the current trajectory and steering to correct the error, and the more time allowed to make corrections, the better.

SpaceX seems to have settled on using one engine for the very last part of the landing even on three-engine approaches; for symmetry reasons this more or less eliminates the possibility of a two-engine approach, because you'd have to change over from two outboard engines to the center engine in a fraction of a second, and engine start times are slightly variable.

1
source | link

As noted, the advantage to doing a higher thrust burn is that it takes less time and therefore uses less fuel.

The main advantage to a slower final approach is that it gives more time for the guidance system to correct the rocket's trajectory. Any guided landing procedure involves a cycle of estimating the accuracy of the current trajectory and steering to correct the error, and the more time allowed to make corrections, the better.

SpaceX seems to have settled on using one engine for the very last part of the landing even on three-engine approaches; for symmetry reasons this more or less eliminates the possibility of a two-engine landing, because you'd have to change over from two outboard engines to the center engine in a fraction of a second, and engine start times are slightly variable.