Importance of lift force, and how to look at it (as entire craft)?

[Jestersage]

I am trying to design a semi-shuttle (that is to say, horizontal atmospheric entry before using parachutes), and I am wondering how important is the lift capability of the wings. EDIT: In particular, it is about extending its crossrange and downrange

All I know so far is to place the CoL behind the CoM.

Edited July 4, 2020 by Jestersage

[bewing]

Almost completely unimportant. Since you are not using your wings during liftoff, and you are not using them to actually land, the only major thing they are used for on reentry is to create variable drag -- so that you can slow down to parachute speeds at the correct moment.

[Jestersage]

Okay, but what if I want to extend by crossrange/downrange? Does lift matter in that case?

[bewing]

Crossrange, yes. You need to apply force without drag to maneuver crossrange. And that means lift.

Downrange, no. You need very little lift to change your impact point by a long distance. Keep your speed and altitude as long as you can, then go to a very bad stall to scrub all your speed with a lot of drag when you are almost over your target. This takes drag more than lift, and any craft that has some control authority in the atmosphere can go into a stall or spin to scrub speed quickly.