STENTOR (Satellite de Télécommunications pour Expériences de Nouvelles Technologies en Orbite) was an experimental communications satellite developed by CNES (the French space agency) in association with French Telecom. STENTOR was designed to carry out propagation and transmission experiments, especially at wavelengths shorter than those presently used for satellites communications. It was lost during the failure of its Ariane 5 launch vehicle on 11 December 2002.