Yesterday operators called off the resuscitation effort on Envisat, the European Space Agency's massive Earth-imaging satellite, after a month of unresponsiveness from the 10 year old satellite. There are several possible causes of the loss of communication. According to space.com, "The failure of a power regulator may be blocking the satellite's telemetry and telecommand systems, ESA officials said. There may have also been a short circuit on board that plunged Envisat into a protective "safe mode," then a second malfunction that left the satellite in an unknown state, incapable of receiving commands from Earth. As a fellow operator, my heart goes out to the Envisat Ops team. I can't imagine anything more frustrating than troubleshooting an unknown anomaly in the blind, with the whole space world watching.
Despite having no comms, the ESA was able to verify that the solar arrays were still deployed thanks to a neat photo from the CNES Earth-observing Pleiades satellite:
|Envisat, as images by Pleiades. Source: CNES|
Though Envisat's death is sad, we should remember that it had a meaningful and long life, (it's initial lifetime projection was only 5 years) and it died doing what it loved.