After several days of delays, New Zealand has officially joined the space race, thanks a successful launch by Rocket Lab.

Its Electron rocket was launched from the Mahia Peninsula on Thursday afternoon.

Rocket Lab says the launch, the first from the site, made it to space and the team is "delighted".

Chief executive and founder Peter Beck said it's the world's first orbital-class rocket launched from a private site.

"We didn't quite reach orbit and we'll be investigating why, however reaching space in our first test puts us in an incredibly strong position to accelerate the commercial phase of our programme, deliver our customers to orbit and make space open for business," he said.