Mars Express Prepares for Phobos Flyby

The Mars Express orbiter has been in orbit around the Red Planet since Christmas Day, 2003, and has produced invaluable amounts of scientific data on our closest neighbor in the solar system. Recently, experts at the European Space Agency, which manage the mission, announced that the spacecraft had just completed its 7777th spin around Mars. Its current altitude and orbit means that it circles the planet once every 6 hours and 54 minutes. As it stands, engineers are currently preparing it for its closest ever encounter with moon Phobos. The “meeting” will take place on March 3, AlphaGalileo reports.

The flyby will be made possible only by the highly elliptical orbit that Mars Express is currently in. It takes the spacecraft about 350 kilometers above the surface of Mars at the point of closest approach, and as far as 10,300 kilometers when the two objects are farthest away. Thanks to this, the orbiter will now be able to conduct scientific measurements of Phobos at an altitude of just 50 kilometers above the moon's surface. This will allow researchers to determine the amount of gravitational pull the natural satellite exerts, and will help determine other physical properties too.

Plans are to use radar sounding and imaging to perform detailed reconnaissance of the space rock's surface, and the Mars Express could even be asked to snap some photos for a map. Radio Doppler data will be used to assess the gravity forces of the moon, which will be very important for a future sample-return mission there. Both the American space agency NASA and the Russian space agency RosCosmos have plans to send spacecraft to Phobos or Deimos, to collect soil samples and conduct scientific measurements on site.

The upcoming flyby could also help geologists figure out the distribution of matter inside Phobos' core, which could help them establish the moon's origins. Many have asked whether the body was formed from Mars, in very much the same way the Moon is believed to have come out of the Earth following a space impact, or the body is simply a meteorite or a comparable structure that was trapped by Mars' gravitational pull and held prisoner ever since.

At this point, the Mars Express mission secures funding to operate until 2012. In its seven years of operation, there have been very little glitches hampering its operations, or that of the seven scientific instruments it carries, and so it's very likely that ESA will decide to prolong the mission until at least 2014. Details of this are scheduled to be discussed later this year.