Just days away from the first fully-commercial rocket launch from Mahia, weather conditions are "looking promising" for a Saturday launch.

Rocket Lab opens a 14-day launch window for its planned commercial launch from Onenui Station on Saturday, and a company spokeswoman said at the moment, the weather looked promising for a successful launch attempt.

"Clear skies and a lack of high altitude wind are ideal launching conditions.

"We'll be keeping an eye on upper level winds and a phenomenon called triboelectrification, which is a build-up of static electricity on the rocket as it soars through high-level clouds."


Niwa principal forecasting scientist Chris Brandolino said so far, the weather outlook was "pretty good".

"I don't think they like to have wind changing abruptly as they go vertically up in elevation, wind shear-especially, that's wind speed changing with height, but in principle if I were launching a rocket on Saturday, I would be pretty optimistic. I would say it certainly looks more favourable than unfavourable.

"There's not going to be a lot of wind, the weather looks pretty quiet. The visibility looks really good, in terms of cloud it looks to be a fairly nice day, pretty clear. There's certainly more clear sky than cloud cover.

"There's a small window between Friday afternoon and Saturday evening when winds increase.

"They've potentially picked a pretty good day.

"As we get into Saturday night the winds will start to increase aloft, not so much at the ground level, but as you travel a mile up.

"Basically, as you go up in elevation, you're removing yourself from the effects of friction.

"Once to get to certain level, the effects of friction aren't there, so airflow will be higher because of a lack of friction."

That meant abrupt changes in wind speed at higher altitude would be felt more.

"But from what I'm looking at, the conditions for that look unlikely. One thing they may have to look out for, the weather looks good, but there could be a frost in the morning. It will be a chilly day for mid to late June."

US orbital launch provider Rocket Lab says the launch window for the "It's Business Time" mission would open from this Saturday until July 6, with daily launch opportunities between 12.30pm and 4.30pm.

The launch window, originally slated for April 20 to May 3, 2018, was moved after unusual behavior was identified in a motor controller during a wet dress rehearsal.

The cause of the issue was found and corrective measures put in place.

With weather expected to struggle to break into double figures on Saturday, Wairoa District Council is encouraging food and beverage sellers to turn out at the official Bluck's Pit Road viewing site in Nuhaka.

"As Rocket Lab gears up for its new rocket launch window, the council is reminding people that they can view the launch in Nuhaka," a council spokesman said.

"It is also encouraging anyone who wants to use the launch window as an opportunity to sell food and drinks at Bluck's Pit Rd to do so.

"Staff will be on-site at Bluck's Pit Rd to help anyone get the best viewing opportunity."

For more information, people could contact business support economic development officer Annalena Atzwanger on 06 838 7309.