The EUNEOS mission: A European NEO space-based observatory

Abstract In the work frame of a recent ESA funded study on the preparation of space missions related to NEOs [EUNEOS, an European NEO Space Observatory Mission in the frame of ESA Study Near-Earth Objects Space Mission Preparation—AO/1-4137/01/F/IZ, March 2003] , Alcatel Space in collaboration with the Observatoire de la Cote d’Azur proposed an innovative concept of space-based observatory aiming at discovering a significant fraction ( ∼ 80 % ) of the PHO population with H 20.5 in 5 years (the EUNEOS goal). To achieve such a level of completeness, a medium size optical telescope on an orbit totally interior to Venus is proposed performing a systematic survey of the selected band of the sky. To reach the proposed operational orbit with virtually no additional manoeuvre after leaving the Earth, a gravitational assist by Venus is envisaged. The paper describes in more detail the proposed architecture of the EUNEOS mission. It reuses as much as possible existing components/entities to keep low the cost of the proposed mission, for example for the user and mission segments. Concerning the space segment, the satellite design takes advantage of the technological developments and studies performed in the frame of BepiColombo and the proposed optical instrument is inspired from the CNES Corotel instrument. This approach allows to propose a relatively mature instrument and spacecraft designs for an answer to a call for ideas. The most complete simulations of the detection process show that the EUNEOS goal is achievable with the proposed system, making it possible in a limited time frame to estimate the risk represented by NEOs of sizes down to a few hundreds of meters.