"Derek Lyons" wrote in message
...

The problem with this statement is... There is nothing modular about
the Apollo spacecraft. The CSM is a matched pair always and forever.


Perhaps KAC meant that the LM and Saturn V launch vehicle could be left
behind or changed out (respectively) for each Apollo mission. For example
for most orbital missions the smaller Saturn IB could be used. Also IIRC
more seats could be added to the CM at the expense of cargo space and
mission length. More or less fuel, or different
equipment, could be carried in the SM too.

However, I think NASA would rather have used something else for Skylab and
ASTP.