Rocket Lab's Pursuit of Reusable Launch Vehicles

Rocket Lab is finalizing preparations for an upcoming launch, scheduled for May, originating from its New Zealand launch complex. The mission will deploy two satellites intended to augment BlackSky’s Earth observation network. However, a key secondary objective underpins this flight: the retrieval of the Electron launch vehicle’s booster stage upon its return to Earth.

Booster Recovery Efforts

This endeavor isn't entirely new for Rocket Lab. Last November, the company successfully recovered a booster from the ocean following the “Return to Sender” mission. The forthcoming flight, designated “Running Out of Toes,” shares a similar aim, but incorporates enhancements to the Electron vehicle. These modifications will enable Rocket Lab to amass further data and advance towards the full-scale reuse of its boosters.

Rocket Lab CEO Peter Beck highlighted the positive condition of the initially recovered booster, noting minimal damage to the thermal protection systems. He explained that the current re-entry method, engines-first, generates substantial shockwaves. The upgraded heat shield for this flight is designed to withstand these increased stresses, leveraging insights gained from the previous recovery.

Data-Driven Improvements

The initial flight yielded crucial data regarding the stresses experienced by the Electron booster during re-entry. This information, previously subject to estimation, was confirmed through onboard sensors. Analysis of this data facilitated a redesign of Electron’s heat shield, resulting in a “major increase in performance and strength,” as stated by Beck.

The second flight will validate these improvements and generate additional data for the Rocket Lab team. This data will inform the design of the third and final planned recovery test. This test will concentrate on refining the re-entry process to reduce the booster’s velocity during atmospheric re-entry.

Optimizing Re-entry and Recovery

Reducing velocity will streamline the final recovery stages, making parachute-assisted deceleration and mid-air helicopter capture more feasible. Beck stated the goal is to minimize velocity to a point where helicopter recovery becomes a practical and reliable method.

The third splashdown test is anticipated later this year. While Rocket Lab doesn’t intend to re-fly the boosters from these development tests, components from the first recovered booster have already been incorporated into the second test vehicle. The company plans to recover and reuse even more parts during the third test.

Analyzing Recovered Hardware

Beck emphasized the value of physically examining the recovered boosters. He explained that dissecting the booster at the Rocket Lab factory provides invaluable insights into the effects of re-entry and identifies the most affected components.

“You can have all the instrumentation you want, but we brought that stage back here and the first thing we did is, we cut it up,” Beck said. “We cut all the heat-affected areas…and then start doing tensile polls on them to understand the material properties.”

Future Commercial Missions

The ultimate objective is to re-fly a recovered Electron booster. Beck anticipates that the first re-flight will likely be a commercial mission, reflecting Rocket Lab’s commitment to safety and reliability. He acknowledged that extensive refurbishment will be necessary, drawing parallels to SpaceX’s iterative approach to reusability.

“I suspect the first reused vehicles will have quite a lot of refurbishment on them…It’s a very iterative process of building confidence and assurance,” Beck explained.

Implications for Neutron Development

The development of Electron reusability is also proving beneficial to Rocket Lab’s larger Neutron launch system. Neutron is being designed for propulsive landing and inherent reusability from the outset.

“Electron was designed to be the world’s most manufacturable launch vehicle — Neutron is designed to be the most reusable launch vehicle,” Beck stated. He hinted that the Neutron’s architecture will clearly demonstrate its focus on reusability, leveraging the experience gained from the Electron program.