The hydrazine thrusters on ESA's Infrared Space Observatory have successfully raised the perigee Of ISO's orbit from 518 km to the operational altitude of 1030 km above the Earth. Commands to he spacecraft's thrusters were sent from ESA's Control Center ESOC in Darmstadt Germany at 13: lo GMT On 19 November. The thrusters were used for a total of 111 minutes and the burn finished at 15:01 hrs GMT.
An apogee lowering manoeuvre is planned for Friday 24 November at 02:45 hrs GMT, again using the hydrazine thrusters, After completion Of this manoeuvre, ISO will have attained its final operational Orbit.
The following milestone will be the ejection of the cover which closes the cryostat of ISO. his operation is planned for Monday 27 November at 10:27 GMT. The scientific instruments will then start receiving infrared radiation from the sky.