In article ,
Vic7 wrote:


That is quite true for a de-orbit landing, but what about a sub-orbital
launch abort? Is an emergency landing site always available after a
certain minimum altitude is reached?

I am certain the engineers have calculated the answer to this question
and the pilot and mission commander have that emergency procedure
memorized, but I have no idea if there are any critical gaps short of
orbit.

There are various scenarios that they have for launch aborts.
Wikipedia has a good writeup:
http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes

There are four basic types of launch aborts. The names pretty
much explain them.

Return to Launch Site (RTLS)
Transatlantic Abort Landing (TAL)
Abort Once Around (AOA)
Abort To Orbit (ATO)

Transatlantic Aborts have various pre-chosen sites in Europe and
north Africa, depending on the launch trajectory.

John
--
John Clear - http://www.clear-prop.org/