The observation of Extensive Air Showers from an Earth-Orbiting Satellite

In this paper we review the main issues that are relevant for the detection of Extensive Air Showers (EAS) from space. EAS are produced by the interaction of Ultra-High Energy Cosmic Particles (UHECP) with the atmosphere and can be observed from an orbiting telescope by detecting air fluorescence UV light. We define the requirements and provide the main formulas and plots needed to design and optimize a suitable telescope. We finally estimate its expected performances in ideal conditions.