Oscar 9 (directly behind Oscar 6) under construction

Oscar 9 was a UNSC D77-TC Pelican dropship. It was constructed in 2552, at the same time as Oscar 5, Oscar 6, and Oscar 8[1].

Although Oscar 9 is not mentioned by name in the film, O9 is clearly visible on the Pelican's cockpit, which conforms to the identification scheme of UNSC Pelicans.

References