Deneb III
From FreeSpace Wiki
Not much is known about Deneb III (except in the actual game) but it is highly likely that Deneb III is a barren and uninhabited planet, due to deductions made from the opening cutscene of Freespace 2, which features the battle of Deneb from the great war, therein a Hercules fighter is shot down by a Shivan Manticore, and spirals uncontrollably towards Deneb III. It is then that you see the wreckage in a barren, sandy and rocky planet, void of any immeadiate life.