Rocket Lab CEO Peter Beck has shared more details on the company’s next launch, which is expected to take off from its New Zealand facility on May 15. The Electron vehicle will carry BlackSky satellites, but providing that payload is only half the mission: the other half will recover the booster stage after a dip in the ocean.
This is the second of three planned booster recovery missions, as part of Rocket Lab’s long-term plan to achieve the reusability of its launch vehicle, a most famous achievement owned by its competitor SpaceX. The first recovery mission, dubbed “Return to Sender”, took place successfully in the Atlantic in November. While Beck told reporters on Tuesday that the condition of this booster was “outstanding,” this upcoming mission nonetheless features a number of component and system upgrades aimed at further strengthening the booster.
Specifically, the booster will be fitted with a redesigned heat shield made of stainless steel, rather than aluminum, “designed to withstand re-entry loads as well as re-entry loads,” Beck said. The electrons must withstand temperatures as high as 2,400 ° C upon re-entry, conditions that the original equipment was not supposed to handle.
The company is also showcasing what it calls the Ocean Recovery and Capture Apparatus, or ORCA, a dedicated system to help lift the rocket stage out of the water and onto the deck of a ship. Rough seas in November posed a challenge to the recovery effort, although ultimately the booster was not damaged.
The mission will also reuse components from the salvaged thruster, which (although the thruster itself was disassembled) were then inspected and requalified for flight. “From now on, we should be able to reuse this system on every pitcher we’ve reported,” Beck said.
Rocket Lab pursues a unique path to reusability. Unlike SpaceX’s approach, whose Falcon 9 rockets use powered decelerations and landings, Rocket Lab’s approach with Electron involves passively decelerating the vehicle using the atmosphere and a parachute.
The method of re-entry is limited by the size of the pitcher, Beck explained. “You don’t really have that ability to carry extra fuel to do deceleration maneuvers or burns or anything like that,” he said. Instead, the vehicle first enters the engines and spreads a massive shock wave on its return trip to Earth, carefully managing to reduce peak heat on its vulnerable parts. This results in an almost negligible payload reduction: around 10%, compared to the 30-40% required for a propellant landing. These are very tight margins, Beck admitted. “It’s not a simple thing to do. It sounds pretty basic – just bring the scene back and put it under a parachute and splash around – but actually doing it without significant re-entry elements and just using the atmosphere to do all the work is really hard.
The final splash recovery mission will take place before the end of 2021, Beck said, and will include decelerator upgrades and a more general block upgrade. Once these missions are completed, Rocket Lab will turn to their ultimate goal of completely removing splash recovery and retrieving the booster mid-descent under their parachute using a helicopter.
Looking ahead, the company’s next rocket will be the Neutron, “a vehicle designed to be reused from day one,” Beck said. The Neutron will be much larger than its predecessor and capable of lifting heavier payloads into orbit. He estimated that Rocket Lab will build one neutron rocket per year and aim to operate a fleet of four to begin with.