First Test : 9 th of May 1935 : Heyst-aan-Zee - Duinbergen
On the 9th May of 1935 Roberti conducted his first Belgian rocket mail experiment on the beach of Heyst-aan-Zee - Duinbergen in collaboration with the Belgian post administration. For the occasion 3 unofficial stamps were designed.
Number of rockets launched : 2
cover from the rocket "Belgica"
cover from the rocket "Zeemeeuw"
All the covers have several of the unofficial stamps especially designed for the occasion on them, some have the signature of Roberti. The official stamps are cancelled by the postadministration There are also private cancellations by the NRB.