Editing Mars Express (section)

=== Orbit insertion ===
[[File:Animation of Mars Express trajectory around Mars.gif |thumb |right |Animation of ''Mars Express''{{'s}} trajectory around [[Mars]] from December 25, 2003, to January 1, 2010<br />{{legend2|magenta| Mars Express}}{{·}}{{legend2| Lime|[[Mars]]}}]]''Mars Express'' arrived at Mars after a 400 million km journey and course corrections in September and in December 2003.

On December 20 ''Mars Express'' fired a short thruster burst to put it into position to orbit the planet. The ''Mars Express'' orbiter then fired its main engine and went into a highly elliptical initial-capture orbit of 250&nbsp;km × 150,000&nbsp;km with an inclination of 25 degrees on December 25 at 03:00 UT (10:00&nbsp;p.m., December 24 EST).

First evaluation of the orbital insertion showed that the orbiter had reached its first milestone at Mars. The orbit was later adjusted by four more main engine firings to the desired 259&nbsp;km × 11,560&nbsp;km near-polar (86 degree inclination) orbit with a period of 7.5 hours. Near [[periapsis]] (nearest to Mars) the top deck is pointed down towards the Martian surface and near [[apoapsis]] (farthest from Mars in its orbit) the high gain antenna will be pointed towards Earth for uplink and downlink.

After 100 days the apoapsis was lowered to 10,107&nbsp;km and periapsis raised to 298&nbsp;km to give an orbital period of 6.7 hours.

The [[MARSIS]] radar booms were originally scheduled to be deployed in April 2004, but this was delayed to 2005 out of fear that the deployment could damage the spacecraft through a whiplash effect.<ref name=":2" />[[File:Mars Express illustration highlighting MARSIS antenna.jpg|thumb|Illustration of ''Mars Express'' with [[MARSIS]] antenna deployed]]{{multiple image
| align             = right
| direction         = vertical
| image1            = PIA07944 Mars Express Seen by Mars Global Surveyor.jpg
| caption1          = Image of ''Mars Express'' in orbit, taken by [[Mars Global Surveyor]]
| image2            = PIA07944 Mars Express Seen by Mars Global Surveyor, Figure 1.jpg
| caption2          = Artist's impression of the expected appearance of ''Mars Express'' at the time of the Mars Global Surveyor image
| total_width       = 250
}}