XMM-Newton spies mother Earth
17 February 2000An unexpected spin-off from the XMM-Newton commissioning phase, thespacecraft has snapped a picture of mother Earth. The image was takenwith one of the two Small Visual Monitoring Cameras (VMC).
The IRIS and Fuga cameras fixed on the outside of the satellite pointing towards the service module had already sent back pictures of the observatory itself during the early orbit phase just before Christmas. Views then also showed the black spacecraft during and just after a thruster firing.
The cameras were on test on 16 February when, for independent reasons, the spacecraft, at an altitude of between 45000 and 50000 km was slewing and pointed towards the Earth. The IRIS colour camera was undergoing a long exposure duration test and unfortunately its image is overexposed and our planet is completely white.
However the Fuga camera with its logarithmic response obtained a nice image of both XMM-Newton and the Earth in the background. The Earth reveals a cloud pattern which matches a picture taken at the same time by Meteosat, in its geostationary position over the Indian Ocean.
The VMC cameras are being activated on a regular basis to check their state of health. The images obtained, and particularly this Earth view confirm that the camera CCDs and electronics are standing up well to the space environment and particularly to the repeated passages through the radiation belts. XMM-Newton was then on its 35th revolution. This verification of the VMC micro cameras is useful in the event of similar ones flying again on other ESA missions.