Electron descending
The Electron booster, descending under a parachute (right), as seen from the helicopter as it attempted to grapple the parachute. The helicopter released the booster moments later, though. Credit: Rocket Lab

Updated after post-launch briefing.

WASHINGTON — Rocket Lab declared success in its effort to catch an Electron booster in midair after launch May 2, even though the helicopter had to release the booster moments later.

The Electron rocket lifted off from the company’s Launch Complex 1 in New Zealand at 6:49 p.m. Eastern after a brief hold in the countdown. The rocket’s ascent went as planned, with the kick stage, carrying a payload of 34 smallsats, reaching orbit about 10 minutes later.

On this mission, dubbed “There and Back Again” by Rocket Lab, the attention was on the rocket’s first stage. After three previous launches where the stage descended under a parachute to splash down in the ocean for recovery by a ship, the company planned to capture the stage in midair using a helicopter. A hook descending from the helicopter would grab the parachute, which would then return the stage to land or set it down on a ship without exposing it to salt water.

The company billed the midair capture as the final step in its efforts to reuse the stage. A successful midair recovery could allow the company to fly the stage again later this year, enabling the company to increase its flight rate without manufacturing more boosters.

About 15 minutes after launch, the descending booster came into view of Rocket Lab’s Sikorsky S-92 helicopter. Video from the helicopter appeared to show the hook grappling the parachute to cheers from mission control. Moments later, though, there were groans and the webcast cut away, suggesting that perhaps the helicopter lost the booster.

More than a half-hour later, Rocket Lab confirmed that the helicopter had grappled, but then released, the booster. “After the catch, the helicopter pilot noticed different load characteristics than what we’ve experienced in testing,” company spokesperson Murielle Baker said on the webcast. “At his discretion, the pilot offloaded the stage for a successful splashdown” for recovery by a boat, like on the three previous recovery attempts.

Despite the release, she called the catch “a monumental step forward in our program to make Electron a reusable launch vehicle.” It was not clear when Rocket Lab would next attempt a midair booster recovery.

In a call with reporters four hours after liftoff, Peter Beck, chief executive of Rocket Lab, called the brief catch a “huge achievement” despite having to release the booster moments later. He said the company had not yet had a chance to debrief the pilots in detail about the catch attempt. “They got a great catch and they just didn’t like the way the load was feeling beneath the helicopter,” he said.

He said he believed it would be “trivial” for the company to determine why catching the actual booster was different from past tests using prototypes. “We’ll probably update our simulator to simulate the load accurately to what it was, go out and do a bunch of tests to get comfortable with the update load case,” he said, arguing that will be much easier than the effort needed to catch it in the first place. “That’s the hard thing.”

The booster splashed down softly in the ocean and was retrieved by a boat a short time later. “Obviously we don’t like tanking it and dunking it in the sea, but there’s still a tremendous amount of the stage and the equipment that we can reuse,” he said. He didn’t rule out trying to fly the stage again. “It’s still my hope that you’ll see this vehicle back on the pad again.”

While the booster catch attempt captured attention for the launch, the primary purpose of the mission was to place 34 smallsats into a sun synchronous orbit at an altitude of 520 kilometers, which the kick stage completed an hour after liftoff. On this dedicated rideshare mission, 24 of the satellites were Spacebee satellites from Swarm Technologies, the SpaceX-owned company that operates a constellation for internet-of-things services, in a launch arranged by Spaceflight.

Also on the launch were three prototype satellites built by E-Space, a startup established by OneWeb founder Greg Wyler, that will test technologies for a future broadband constellation. Alba Orbital flew four small satellites for itself and various customers.

Unseenlabs had its BRO-6 satellite for location radio-frequency signals. Aurora Propulsion Technologies launched its AuroraSat-1 spacecraft to test debris removal technologies. A New Zealand startup, Astrix Astronautics, included a technology demonstration payload called Copia that will remain attached to the kick stage.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...