The helicopter was supposed to hock the parachute line, around 15 minutes after liftoff, then carry the booster back to shore.
But the rocket never came into view on a livestream from the helicopter (above).
At around the 17-minute mark, Rocket Lab said it had decided to opt for a water retrieval. A ship was standing by. The Kiwi-American firm has staged a number of previous splashdowns. In September, the firm said it had successfully re-fired the Rutherford engines on an Electron booster retrieved from the ocean.
Rocket Lab pinned the failure on a loss of telemetry data. The helicopter crew was scanning for the booster via tracking electronics, as well as the lower-tech looking out the window. The former failed during re-entry. The firm is investigating.
It was Rocket Lab’s second attempt at a mid-air helicopter catch.
The first (see the Twitter clip below) was on May 3.
It saw the Sikorsky successfully hook the parachute line as the booster fell at 10 metres per second.
But just 40 seconds later, the pilot made the decision to release the rocket as it swung beneath the helicopter as he grew wary of instability.
The first stage was subsequently retrieved after splashing into the seas.
“The chute reinflated. It was a nice soft splashdown. We successfully recovered it from the ship and it’s now on its way back to the factory. It’s just a bit wetter than we’d hoped,” Rocket Lab founder Peter Beck told the Herald.
Beck said he backed the pilot’s decision.
“He captured it, he took the load, and the load wasn’t as we expected and simulated. He did exactly the right thing, because it was outside the strict bounds we’d established. But really, it was a nothing. It was the last 1 per cent.”
The first stage weighs around 1 tonne. The S-92 can carry around 5 tonnes.