On May 9, 6:36 pm, "Jorge R. Frank" wrote:

DOS was never the OS for the space shuttle.

When MS-DOS was on the table, the choice was made to use 68000 chips
and the OS-9 operating system instead.
But the avionics systems were never based on consumer hardware or
software at all.

The avionics are distributed among hundreds (about 300) separate
specialized control units. These were designed from the ground up
specifically for the Shuttle. These control units are interfaced to
"General Purpose Computers".

At one time, the GPCs were based on a Motorola 68000, but a special
one that was designed for the space program.
That one ran OS-9. It was actually the second generation GPC, in
84.

There have been many, very significant changes in the shuttle since
the mid 80s. (Again, people seem to think because the orbiters have
the same airframes, they are just being flown with the same complement
every mission).