Second test : 04 th of September 1935 : Heyst-aan-zee - Duinbergen
Roberti conducted his second test again on the beach of Heyst-aan-Zee - Duinbergen in collaboration with the Belgian postadministration. The tests took place in the late evening. Again 3 unofficial stamps were designed especially for this occasion.
Number of rockets launched : 2
cover from the rocket "Jupiter"
cover from the rocket "De Schelde" - the rocket exploded!!
All known covers are signed by Roberti. The official stamps are cancelled by the Belgian postadministration . On the covers appear also the private cancellations by the N R B. No covers available with the 3 special designed unofficial stamps who are pictured below