Rocket Lab successfully completed the recovery of its Electron rocket’s first stage during the Return to Sender launch on November 20. During the test, Rocket Lab, the makers of one of the most 3D-printed – and actually operational – rocket and rocket engines in the world, returned Electron’s first stage to Earth under a parachute system for a controlled water landing before they were collected by a salvage vessel. .
The mission marked the first time that Rocket Lab has attempted to restore a post-launch stage and is an important milestone in Rocket Lab’s drive to make Electron a reusable rocket to support increased launch capability for small satellite missions. Future mission projects include the ability to recover the first stage while still in the air via helicopters.
The Return to Sender mission, Rocket Lab’s 16th Electron launch, was launched from Launch Complex 1 on New Zealand’s Māhia Peninsula. The mission also saw Electron deploy 30 payloads to a series of small satellite customers in 500 km solar synchronous orbit, with the recovery attempt as a secondary target of the launch.
Electron’s first stage undertook the following complex maneuvers on its journey back to Earth:
About two and a half minutes after launch, at an altitude of about 50 miles (80 km), Electron’s first and second stages separated according to standard mission procedure. Electron’s second stage continued in orbit, where the Kick Stage separated and deployed the satellites.
With the engines turned off on Electron’s first stage, a response control system has reoriented the stage 180 degrees to place it at an ideal angle for return, designed to allow it to survive the incredible heat and pressure known as “the wall” during its descent back to earth.
After slowing to below Mach 2, a drogue parachute was deployed to increase drag and stabilize the first stage as it descended. In the last kilometers of the descent, a large main chute was deployed to further slow down the stage and allow a controlled splashdown.
A Rocket Lab ship met the stage after the crash and collected it for transport back to Rocket Lab’s Production Complex for inspection.
Electron’s first stage is equipped with guidance and navigation hardware, a response control system, S-band telemetry and on-board computer systems to aid recovery. These stand-alone systems are for recovery only and are completely removed from the systems that perform the primary mission functions: launch and deployment of payloads.
Work on Rocket Lab’s recovery program began in early 2019 and the ‘Return to Sender’ recovery effort followed a series of successful tests of recovery and hardware systems over the past 18 months. These include a successful aerial capture of a test missile podium by a helicopter; successful drogue and main parachute deployment tests in subsequent mock drills dropped at altitude; and successfully guided re-entries of the Electron’s first phase during two real-life missions in December 2019 and January 2020 respectively.
The final phase of Rocket Lab’s recovery program is now to capture Electron’s first stage in the air by helicopter before returning the stage to Rocket Lab’s production complexes for renovation and reboot. If Rocket Lab’s recovery program is successful, Electron would become the first and only reusable small orbital class launcher.