Because you have to be able to take them on the plane, obviously. /s
But seriously I think 'fitting in a suitcase' wasn't the design goal, per se, but an approximate description of the design goals. The engine was designed to go in a missile.
That’s interesting actually - and a lot of 1950s era ‘small enough to fit in a suitcase’ descriptions (computers, nuclear warheads, jet engines…) make more sense if you realize they are a euphemism for ‘small enough to fit in a missile’. Makes me wonder what ‘small enough to fit in a cigar box’ was a euphemism for.
That's a euphemism for cigar boxes; smuggled cigars get through borders with a little rake-off at each inspection. The fact that they are actual cigars on the top layers allows all the boxes to get past slightly bent but nonetheless patriotic guards.
Eh, maybe. The suitcase itself is also, more simply, literally just something designed to be a reasonable amount of stuff that a human could carry. Many early portable PCs (e.g. Osborne) targeted a suitcase form factor just because it was a reasonable form factor for people to carry around.
And the comparison is something colloquially convenient. "The device was the size of a suitcase" is just more illustrative than "the device was 50 liters in volume"
But seriously I think 'fitting in a suitcase' wasn't the design goal, per se, but an approximate description of the design goals. The engine was designed to go in a missile.