The command was sent to the spacecraft by the Mission Control Centre at ESA's Villafranca ground station, near Madrid, Spain from where the satellite is now being controlled. The handover of ISO operations from ESA/ESOC to Villafranca took place as planned on 21 November.
With the opening of the cryostat, ISO's telescope is now viewing the stars. The scientific instruments are receiving infrared radiation from the sky for the first time and a detailed check of their alignment and performance can begin. First astronomical images and spectra will be obtained in a few days.