MaqSat 3 (Maquette Satellite 3) was a dummy satellite, which matches the mechanical properties and dynamical characteristics of the originally planned payload, the Eutelsat W2. A condition for the contract with the Munich-based space company Kayser-Threde called for a short delivery period of only three months. On September 1st, the dummy structure with a mass of 2,600 kg and a length of more than 3 m was flown to Kourou, Europe's spaceport. Launch took place on 21 October 1998.

Due to the unavailability of the originally planned telecommunications satellite W2, Arianespace opted for the flight of a dummy payload. This third and last test flight of the new carrier Ariane 5 primarily aims at reaching GTO and at taking up commercial business with flight 504 as soon as possible.

ARD was the Advanced Reentry Demonstrator, built by ESA. This is developed for experimental purposes to validate re-entry techniques.
It was deployed on a suborbital trajectory.