UPDATE: The launch was on time and successful.
Rocket Lab says it's on track to launch its 'A Data With Destiny' launch just after 1pm today.
The lift-off will be livestreamed below.
The company originally pitched the mission as the fastest turnaround in its history.
The original launch window of December 7 would have been just 19 days after its last mission.
But ultimately it was nudged forward a couple of days and will now equal the 21-day mark set last December.
The mission will carry satellites for commercial Earth-imaging company BlackSky.