Comet Siding Spring hurtled past Mars at about 56 km/s only 139 000 km away from its surface at 18:27 UTC on October 19, 2014. The period when dust from the comet was most likely to reach Mars and the orbits of spacecraft around Mars peaked about 100 minutes later. According to mission reports from NASA, ESA and ISRO, all 5 spacecraft in its orbit and 2 robots on the surface are in good shape and healthy.
Thanks to the DSN radio-science receiver at Madrid (then Goldstone) ESA said it could follow the Mars Express S-Band beacon practically all the time, including closest approach and comet plane crossing. Despite the very low level of concern, this was quite good to have, Mars Express control said in a report today.
"After flyby, acquisition of signal occurred as planned [at 20:25 UTC], which implicitly confirmed that the spacecraft is operating normally. First systematic checks of spacecraft telemetry were performed for all sub-systems and showed fully nominal behaviour. There are no unexpected events o...
