The launch was scrubbed yesterday because of the proximity of the International Space Station and deteriorating weather.
In May, the New Zealand-founded company's first test rocket made it to space but the mission was terminated before it reached orbit because of a communication glitch.
The rocket this week will carry two Earth-imaging Dove satellites for Planet and two Lemur-2 satellites from Spire for weather mapping and ship traffic tracking.
If needed, the company will launch a third test flight but it is keen to accelerate its transition into full commercial operations.
Rocket Lab is largely funded by United States companies and has its corporate headquarters in Los Angeles. It says it has an advantage over larger competitors because its smaller rockets can be launched more frequently from an area with very little air traffic. It is aiming for high frequency launches of small satellites.
In May then Economic Development Minister Simon Bridges said if fully developed the space industry could rival that of the wine or kiwifruit industries. Last year the kiwifruit sector was worth close to $2 billion and the wine industry $1.6b.