Watch: Live stream of Rocket Lab's launch attempt from New Zealand's Mahia Peninsula

Rocket Lab successfully a rocket from Mahia in May but it didn't reach orbit. Picture / supplied.

Rocket Lab's Electron rocket is on the launch pad on Mahia Peninsula ahead of its attempt to reach orbit.

Weather is good for the attempt for the 17m-tall launch vehicle called ''Still Testing'' which if successful will be a major milestone for the programme begun 11 years ago.

The last attempt in May successfully made it to space but not to orbit, the purpose of the programme to deploy small satellites at a fraction of the cost of its overseas competitors.

Early today roads in the area were shut and marine traffic notified of a potential hazard. Air traffic has also been warned of a potential hazard in the area from the rocket which if successful will accelerate to speeds of 27,000kph towards orbit.

Yesterday the launch had to be scrubbed as weather deteriorated and the window for lift-off was narrowed by the proximity of the International Space Station.

Observers with the Wairoa District Council said they expected a good turnout of spectators. About 65 people have visited the site since Rocket Lab announced a 10-day launch window last Friday.

More keen spectators are filing into a special rocket observation site, about 27km from where Rocket Lab plans to launch a satellite-bearing rocket into orbit.

Yesterday tourists are turning up at the scene, some happening on the action on their way to the beach. Max Schneider from Germany said his curiosity was piqued by a signpost.

"I was just driving past and saw the sign. We had to come and look at what it was."

Local man Corey Isherwood is one of about a dozen interested viewers and was confident of a successful launch. "I live in Mahia so I thought I would pop over, given the weather."

The sky was almost cloudless, with no detectable wind, and only a slight heat haze interferes with the view of the peninsular from the observation site.

The gathered observers are being offered sunscreen and water as the excitement builds. Many have binoculars trained across the water to the launch pad.

The Electron rocket can be seen nestled on the headland at the very topmost point of the peninsula.

This afternoon the rocket was carrying two Earth-imaging Dove satellites for Planet and two Lemur-2 satellites from Spire for weather mapping and ship traffic tracking.

The company warns the launch could be scrubbed right up to lift-off if the weather changes or there are technical issues preventing it.