No it didnt
Well no-one's actually completely sure, some people have guessed it Onyx from the book "Ghosts of ONYX", but that's quite unlikely considering that it gets distroyed at the end of the book.
Onyx is a forerunner shield world built to protect them from the halo arrays
Halo: Ghost of Onyx is the 4th book in the Halo series.
It is the planet Onyx from the Halo books. Many severely injured or alive SPARTANS are supoosed to be on this planet.
It is kinda hard to explain but it's kinda like a safe place. if the halos are activated then you're safe in there.its a planet but its inside-out. you live inside it instead of on the planet
Go play the game yourself, or search Halo 3 Ending on youtube.com
What happens after the book Halo: Ghosts of Onyx has yet to be determined. The Halo novel that followed this one is called Contact Harvest. It is a prequel to the novels and tells of the first encounters between Human and Convenant forces and the beginning of the war. The Spartans from Onyx, I assume, are still alive because they are trapped in an Earth-like Dyson Sphere that may bear the neccesities to survive, such as food and water. Hopefully the story will be continued through another novel and finished.
Nobondy really knows, although there are many guesses, there is no definitive answer as of now. I will tell you this, I have heard many people say that it is Onyx, however Onyx was destroyed at the end of the book, The Ghosts of Onyx, and therefore cannot be that. There was a Marathon symbol on the planet there, however it is doubtful this actually has anything to do with the Marathon game series or what the planet itself is, and is most likely just there as a nod to long-running Bungie fans. He is believed to be floating towards the forerunner homeworld, because if you visually compare the planet on an HD screen with the brightness turned up, it is a match to the Forerunner homeworld in HALO Legends
Halo : Fall of Reach Halo : The Flood Halo : First Strike Halo : Harvest Halo : Ghosts of Onyx
There is no "Halo 4" as of yet, but it is rumored that there will be something like it produced. It is said to take place on the Shield-World, as described in the book "Halo: Ghost of Onyx". This Shield-World is said to be shown in the final cut-scene in Halo 3 on Legendary.
The unknown planet seen at the end of Halo 3 is believed to be Installation 04B, a replacement Halo ring built after the destruction of the original Installation 04. It fades out in the last cutscene to indicate that the Master Chief and Cortana are adrift in the remains of the artificial ring world, setting the stage for Halo 4.
Some Halo chapter books include "Halo: The Fall of Reach" by Eric Nylund, "Halo: First Strike" by Eric Nylund, and "Halo: Ghosts of Onyx" by Eric Nylund. These books expand on the Halo universe and provide additional background and stories to complement the video games.