This is easier than landing on a strip. Reaching a specific point in space is a much looser constraint than reaching that same point with the correct velocity and acceleration to make a landing feasible beyond that point. There are way more unique trajectories (flying straight down into the point, approaching off-normal from the building face, sideways, upside down, relatively level, even skipping off the ground) that satisfy the first constraint that would not satisfy the second constraint.
This is easier than landing on a strip. Reaching a specific point in space is a much looser constraint than reaching that same point with the correct velocity and acceleration to make a landing feasible beyond that point. There are way more unique trajectories (flying straight down into the point, approaching off-normal from the building face, sideways, upside down, relatively level, even skipping off the ground) that satisfy the first constraint that would not satisfy the second constraint.
At an estimated 850 km/h there is very little margin for error with regards to these unique trajectories however.
I agree, safely landing at 850 kph sounds tough
Ground effect would help: https://en.m.wikipedia.org/wiki/Ground_effect_(aerodynamics)