An announcement made at AnimeJapan 2014 revealed that a new 2-episode OVA for Suisei no Gargantia
will be coming Fall 2014. The screening event for the first OVA was announced as well. More information on the OVA will be given at a later time.
Previous related news: Anime 'Suisei no Gargantia' to Get Sequel
Suisei no Gargantia OVA