The French were gonna use the Veronique Sounding Rocket for the IGY but the French Economy
was not in good shape so the Veronique Sounding Rocket was put on hold and the Monica used in its place
The first stage diameter is bigger than the 2 upper stages. On different versions of the Monica
the 1st and 2nd stage diameter was bigger than the 3rd stage. And on 1 version all 3 stages
used the bigger diameter. Each stage of the Monica has its own unique name.
The Monica was used during the International Geophysical Year IGY ( 1957-1958 )