CPV code 73435000 designates Test and evaluation of military aircrafts, missiles and spacecrafts in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
73435000 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 73430000 (Test and evaluation).