Those who wondered how Bungie was going to plausibly explain the presence of Nicole-458, the Spartan II soldier who guards the hangar bay of the Nassau Station in Tecmo's upcoming DOA4 title for the Xbox 360, will get a hearty "shut your noisehole" and a shout-out to the I Love Bees reality game in Frankie's run-down on Nicole, Spartan-458:
Nicole was born in the year 2531 in the city of New Legaspi on Mars. At six years of age she was abducted by agents of the Office of Naval Intelligence and conscripted into the Spartan II program. The Spartan II program was the UNSC's highly successful military project to augment and hone perfect soldiers.
SPARTAN-458's unit was preparing for a classified mission on Nassau Station when the ONI stealth ship Apocalypso tumbled into real-space – being carried along in the wake of a freak slipspace anomaly. The anomaly intersected Nassau Station; creating a semi-stable "bubble" in the space/time continuum on its way back to the 21st Century.
For the time being Nicole-458 is trapped in the 21st century; guarding Nassau Station's secrets with all but lethal force (she realizes killing someone in the past could have dire consequences), waiting for the "bubble" to collapse and hopefully returning her to the year 2552.
The Apocalypso, some of you might recall, was the UNSC craft that the AI Melissa was aboard, and that brought the mysterious artifact to Earth that Spartan-spawn Janissary James had to try and deactivate before it... did something bad.
Whether this mishap involving a cloaking device and a space station (sounds like a line from Hitchhiker's, doesn't it?) occurred before or after Truth's fleet arriving at Earth isn't specifically stated; but as the Nassau's hangar bay happens to include a conveniently-placed Covenant boarding craft, one can only assume the latter. Either that, or this is really just the Cairo's hangar from Halo 2. Wait, did I say that out loud? Nevermind.