The title refers to the empty regions of space, where there are no planets or stars for huge distances.
When Sheppard's F302 comes into view attached to the Wraith ship, the "Emergency EVAC" sign is seen and looks just like similar signs used on the Enterprise NX-01 in Star Trek: Enterprise (2001) (fonts, lettering style, layout and colors).
Robert Picardo (Richard Woolsey) is one of many Star Trek actors to appear on Stargate: Atlantis (2004). He, also, appeared as the same character on Stargate SG-1 (1997), too. Other notable Trek actors on Atlantis include Colm Meaney, Connor Trinneer, Nicole de Boer, Steven Culp, and Alan Ruck.