How can data travel from Mars to the Earth?

Question Title: 
How can <font size="32">data</font> travel from <font size="32">Mars to the Earth?</font>
Short answer: 

Pictures and videos coming from Mars show more and more faithfully what future astronauts would see from their spaceships. But how are space data currently transmitted to the Earth? At ISTC the Planning and Scheduling Technology Laboratory (PST) has developed a solution to complex scheduling problems by applying Artificial Intelligence technology. 

Extended answer: 

The first spacecraft sent by the European Space Agency (ESA) in the Solar System entered Mars's orbit in 2003 and has since then performed excellently. It is called Mars Express because of its rapid development time and it uses sophisticated instruments to study the geology, atmosphere and surface environment of Mars. It has returned extensive spectrometric science data, including breathtaking 3D color pictures and videos confirming the presence of water on the Red Planet’s rocky terrain.

The huge amount of information generated by the spacecraft must be downloaded to Earth in the correct sequence. Traditionally this task was managed using human-operated scheduling software sending commands to Mars Express and telling it when to dump specific data packets. This was excessively time-consuming and a simple mistake could lead to permanent loss of data, as the onboard memory is limited and after a certain time it is overwritten by newly collected information.

But in 2004 the Planning and Scheduling Technology Laboratory (PST) developed a solution to this problem. Its name is Mexar2 and it is an advanced software tool for continuous support to data dumping activities. Its integration in the Mars Express mission planning system has largely eliminated any loss of stored data packets: it works by intelligently synthesizing the commands to be uploaded onboard the spacecraft for returning memory data to the Earth.

Mexar2 reduced the mission planning team’s workload by 50 percent compared to the old manual method. Thanks to PST Mars Express has thus become the first European deep-space exploration mission using a value-adding Artificial Intelligence technology. This success led the group to work on new possible applications of these techniques to space missions.

Contact: Amedeo Cesta

ISTC Group: Planning and Scheduling Technology Laboratory