An announcement made at AnimeJapan 2014 revealed that a new 2-episode OVA for Suisei no Gargantia will be released with the first episode coming Fall 2014. The screening event for the first OVA was announced as well. The first episode will be released on Blu-ray November 21st, with the second coming on May 27th, 2015. More information on the OVA will be given at a later time.
Suisei no Gargantia: Meguru Kouro, Haruka OVA 1 screen caps:
Key-chain offered with advanced ticket sales: