Battle of Heliopolis (Conflicted Hearts)

The Battle of Heliopolis, also known as the Collapse of Heliopolis, was a battle between ZAFT and both the Orb Union and OMNI Enforcers.

The purpose of the battle was the capture or destruction of all the Earth Alliance's Prototype Mobile Suits and the destruction of the experimental LCAM-01XA Archangel Assault Ship, the battle was semi-successful but led to ZAFT following an extended hunt for their remaining targets for the duration of much of the following year.

Original Infiltration
ZAFT at first performed a two-pronged attack, their goal was to use their Mobile Suits to overpower Heliopolis' defenses while a team of infiltrators set bombs about the Archangel's Drydock, and steal the experimental Mobile Suits before they could be moved from the Space Colony to friendly Earth Alliance territory.

Once the Experimentals were captured, the GINNs would maintain security while the pilots flew them from the Colony, and into ZAFT's waiting hands.

This plan however reached a number of problems; ZAFT did not anticipate the possibility of a few of their elite pilots dying in battle, nor did they expect that the Archangel would survive, or that the Archangel's remaining crew would be capable enough to fly it somewhat effectively. They totally did not expect that non-PLANT allied Coordinators would gain control of a number of the Experimentals, become sympathetic to the Earth Alliance's misguided cause, and set up a defensive cordone.