Complex sentence: On 26 October 2009 and again on 25 November 2010 "Scott" deployed to the South Atlantic and Antarctic to cover for the non-availability of the Royal Navy icebreaker HMS "Endurance".
Split into simpler sentences: On 26 October 2009, "Scott" deployed to the South Atlantic and Antarctic. This is in part to cover for the non-availability of the Royal Navy icebreaker HMS "Endurance".