On 4 Oct 2017 at 20:12, Evyn MacDude wrote:

> 2nd Take-offs and landings are much simpler, streamlining becomes
> optional. Primarily it is for ships that do lots of high speed lower
> atmospheric maneuvering. (Hint, if a balloon can reach orbit so can a
> unstreamlined ship).

A balloon can't reach orbit. It can barely reach the lower edge of
orbital altitude. Max altitude attained by a balloon is 53km. That's
a long ways from a viable oribital altitude.

Also, a balloon *is* streamlined. Or at least "neutral" with respect
to wind forces.

Unstreamlined craft have trouble in atmosphere not just because of
high velocity. At lower velocities they'll have problems with wind
loading.

Unless the center of pressure (the point at which aerodynamic forces
"center" as determined by the shape of the hull) is behind the center
of gravity (where inertial forces center, determind by mass
distribution) with respect to the direction of travel, wind forces
and the forces from motion thru the air will try to change the
orientation of the ship until the CP *is* behind the CG.

Worse, if they are too close together, the ship may have a tendency
to "tumble" in the relative airstream.

This kind of thing is how semis running empty or with a light load
get blown over or otherwise messed up in strog crosswinds.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com