In a significant achievement, public launch provider Rocket Lab has – with a few caveats – successfully used a helicopter to catch the booster of its Electron rocket out of mid-air on the very first attempt.
The company began working on ways to recover and reuse the booster of its tiny Electron rocket in 2019, going back on a promise repeatedly made by founder and CEO Peter Beck in the years prior. Due to just how small the Electron rocket is, it was generally assumed that Beck wasn’t wrong to avoid attempting to recover or reuse its parts of it. However, that attitude quickly changed when the need to ramp up launch cadence became a leading priority. Soon after, Beck revealed that Rocket Lab engineers had looked more carefully at the problem and concluded that Electron booster recovery was more feasible than assumed.
Once the problem was no longer deemed insurmountable, the allure of reuse – intrinsically multiplying the effectiveness of any given production line if done right – was irresistible.
While the change in attitude made Rocket Lab the second company after SpaceX to begin seriously developing the ability to recover and reuse orbital-class liquid rocket boosters, the approach it would need to take for a rocket as small as Electron was almost nothing like that used by Falcon boosters. Instead of multiple in-flight engine ignitions, supersonic retropropulsion, steerable fins, and a propulsive landing, Electron would rely on several parachutes to slow itself down, use small thrusters (not unlike Falcon) for attitude control, and be actively captured out of mid -air by a crewed helicopter.
Ironically, demonstrating the sheer size gap between Electron and Falcon 9, Electron booster recovery more closely resembles Falcon 9 fairing recovery. Weighing in at around one ton (~2200 lb) per half, or about as heavy as an entire Electron rocket booster, each fairing half mainly just controls its attitude with cold-gas thrusters while passively reentering Earth’s atmosphere. Fairing halves then deploy a GPS-guided parafoil and gently splash down on the ocean surface before being fished out of the water by a waiting ship.
That is exactly how Rocket Lab trialed Electron recovery on several prior attempts, fishing intact boosters out of the Pacific Ocean after gentle ocean landings. For a while, SpaceX even attempted to catch fairings out of mid-air – albeit with a highly-modified ship and net instead of a helicopter and hook. However, when the company realized it could easily reuse fairing halves that landed in the ocean, it fully abandoned catch attempts.
In Electron’s case, it’s no surprise that Rocket Lab still pursued catch-based recovery while SpaceX was simultaneously giving up on the practice. Put simply, it would be incredibly difficult to reliably and affordably reuse a liquid rocket booster – and liquid rocket engines especially – after dunking them in saltwater.
That’s also why the success of Rocket Lab’s first operational catch attempt has caveats. While the company did successfully catch the booster out of mid-air, the pilot – who holds final authority for the sake of safety – observed unusual behavior not seen during testing after hooking Electron and chose to release the booster early. Thankfully, it still managed a soft landing in the ocean and was recovered by ship, but despite statements from Beck to the contrary, that seawater exposure will almost certainly make it impossible to fully reuse. To call the attempt a total success, the helicopter would have needed to drop the booster off on the recovery ship’s deck, fully avoiding a bath.
Above all else, even if the catch didn’t last, Rocket Lab successfully launched 34 small satellites and payloads into orbit for several paying customers and briefly caught the booster that launched them with a helicopter. The attempt was arguably far more successful than not and likely leaves Rocket Lab just a little more practice and a few small optimizations away from a perfect recovery. Then the company can shift its focus to the next goal: the first Electron booster reuse.