Measurement requirements for a Near-Earth Asteroid impact mitigation demonstration mission

► We present results of a study for a space mission to an asteroid. ► Don Quijote: Impactor spacecraft changes asteroid orbit; Orbiter measures change. ► Payload is prioritised through trade-offs, taking into account mission objectives. ► Orbiter must carry a thermal IR spectrometer, to account for the Yarkovsky effect. ► Also discuss Radio Science Experiment, laser altimeter, wide-angle impact camera.