Rocket Lab countdown to lift-off: What's happening at the Mahia launch pad

Rocket Lab's second test vehicle is undergoing final checks at Mahia today. Photo / Supplied

Rocket Lab hopes it will get its second test Electron rocket into orbit this afternoon.

The launch follows a successful lift-off in May when the first test vehicle reached space but not orbit as a communication glitch meant the mission had to be terminated.

Rocket Lab warns the launch could be scrubbed at any time due to poor weather or technical problems with the 17m rocket.

This is what is happening on the Mahia Peninsula, near Wairoa, this morning:

Countdown to lift-off

T-minus 7 hours: Emergency crews, local officials and Rocket Lab team briefed.

- 6 hours: Road to site closed-4 hours: Kerosene pumped into rocket

-2 hours 30 mins: Launch pad personnel leave site

- 2 hours: Liquid oxygen is added

-1 hour: Aircraft warned of pending launch

-2 minutes: Auto sequence starts and onboard computers initiate launch sequence

-2 seconds: Ignition of Rutherford engines powers first stage

0.00: Lift-off: Electron climbs from the launch pad

Powering into space

•The Electron rocket weighs more than 12 tonnes at lift-off - about the same as a double decker bus

•Its nine Rutherford engines produce enough thrust to lift that from a standing start

•Power to weight, it is the most powerful machine in New Zealand

•It will take about three seconds to clear the four-storey launch tower

•It will climb to more than 10,600m feet in a minute

•Once past the thicker parts of the atmosphere it will reach 27,000km/h

•Stage 1 of Electron separates after two and a half minutes

•After just over eight minutes Electron reaches orbit about 500km above the earth

•At eight and a half minutes payload separates from the launch vehicle

•It can carry a payload of up to 225kg

•Once in commercial operation launches will cost customers about $7.16m.

•All loads are licenced by international and NZ space authorities