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Listen to Phoenix descend ![]() Animation showing artist's impression of Phoenix during the entry, descent and landing (EDL) phase on 26 May 2008. At the request of NASA, ESA's Mars Express monitored radio signals from Phoenix using the MELACOM lander communication system, orignally intended for use with the Beagle lander. The recorded data will serve as a useful and potentially crucial back-up to compare Phoenix's planned and actual descent profiles. Landing is planned for 23:38 UTC, 25 May, which is 01:38 CEST, 26 May. As Mars Express flew over ![]() This animation shows the signal of Phoenix’s descent, recorded by MELACOM. The spike in the animation, between frequencies of 7 and 8 kiloHertz, shows the transmission from Phoenix itself. The lander can be seen in the animation starting from about 342 s after the start time and disappears at about 1085 s. This shows Mars Express picking up on the Phoenix signal and tracking it while closing in on the lander; the closest Mars Express got to Phoenix was 1550 km. As Mars Express flew away, the lander deployed its parachute, separated from it and landed, the signal from the lander was cut off. The shift of the spike seen in the animation, is due to the so-called Doppler effect, which is very similar to what we hear when listening to the whistle of a passing train. The signal was tracked successfully, even during the expected transmission blackout window of the descent, until the lander was out of Mars Express’s view. The transmission blackout window is caused because of ionisation around the probe, which builds up as the lander descends through the atmosphere and only very weak signals come through. The rest of the recording (start and end) contains background noise generated by Mars Express itself. Science observations ![]() An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a six-month journey, and has been investigating the planet since early 2004. Release date: 30 July 2008 |