Electron uses two stages with the same diameter () filled with
RP-1/
LOX propellant. The main body of the rocket is constructed using a lightweight
carbon composite material. There are nine Rutherford engines on the first stage and one vacuum-optimized version on the second stage. Rocket Lab has also developed an optional third stage, known as the "kick stage", designed to circularize the orbits of its satellite payloads. The Electron kick stage is equipped with a single
Curie engine that is capable of performing multiple burns, uses an unspecified "green"
bipropellant, and is 3D printed. It was first used during Electron's second flight. The kick stage can transport up to of payload. Rocket Lab has also developed a derivative spacecraft of the kick stage,
Photon, which is intended for use on lunar and interplanetary missions. Photon will be capable of delivering small payloads of up to into lunar orbit. The Electron payload Fairing is 2.5 m (8 feet and 2.4 inches) in length with a 1.2 m (3 feet and 11.2 inches) diameter and a total mass of 44 kg (97 lbm).
Production Manufacturing the carbon composite components of the main flight structure has traditionally required 400 hours, with extensive hand labor in the process. In late 2019, Rocket Lab brought a new robotic manufacturing capability online to produce all composite parts for an Electron in just 12 hours. The robot was nicknamed "Rosie the Robot", after
The Jetsons character. The process can make all the carbon fiber structures as well as handle cutting, drilling, and sanding such that the parts are ready for final assembly. The company objective as of November 2019 is to reduce the overall Electron manufacturing cycle to just seven days. Rutherford engine production makes extensive use of
additive manufacturing and has since the earliest flights of Electron. This allows the capability to scale production in a relatively straightforward manner by increasing the number and capability of 3D printers. Electron was not originally designed to be a
reusable launch vehicle as it is a
small-lift launch vehicle but was pursued due to increased understanding of Electron's performance based on analysis of previous flights through sensors on the vehicle. In addition, reusability was pursued to meet launch demands. To counteract decreased payload capacity caused by the added mass of recovery hardware, performance improvements to Electrons are expected. Rocket Lab has not released information on aerodynamic decelerator that would be required to slow down the booster after atmospheric reentry. Later, Rocket Lab abandoned the plan to catch the stage with a helicopter, and will use ocean landing instead. One recovered Rutherford engine passed five full-duration hot fire tests and is declared ready to fly again. Rocket Lab's 40th Electron mission successfully reused a refurbished Rutherford engine from a previous flight.
Aerothermal decelerator Rocket Lab, while investigating reusability, decided that they will not pursue propulsive
recovery like SpaceX. Instead they will use the atmosphere to slow down the booster in what is known as "aerothermal decelerator" technology. The exact methods used are proprietary but may include keeping proper orientation when reentering the atmosphere and other technologies.
Vehicle modification history The Electron initially had a payload capacity of to a
Sun-synchronous orbit. After stage separation, the first stage using the new hardware installed flipped 180° to prepare for reentry. Throughout the reentry the stage was guided though the atmosphere such that it has the right orientation and angle of attack for the base
heat shield to protect the booster from destruction using RCS and onboard computers. The booster successfully survived its guided re-entry despite having no deceleration hardware onboard and destructively splashed down into the ocean at as planned if reentry was successful. Rocket Lab had no plans to recover the stage and instead wanted to demonstrate the ability to successfully reenter. No further atmospheric reentry tests similar to flight 10 and 11 are expected. Following
Flight 11 ("Birds of a Feather"), in mid-February 2020, low altitude tests were done to test parachutes. In April 2020, Rocket Lab shared the successful demonstration of mid-air retrieval done in March 2020. An Electron test article was dropped by a helicopter and deployed its parachutes. A helicopter carrying a long-boom snagged a drogue line from the parachute at demonstrating a successful retrieval. Following the catch the test article was brought back to land.
Flight 16 ("Return to Sender"), was the first to recover the first stage booster, with a splashdown into the
Pacific Ocean. The rocket also lofted thirty payloads into
Sun-synchronous orbit, including a titanium mass simulator in the shape of the garden gnome "Gnome Chompski" from the video game
Half-Life 2. In August 2020, Rocket Lab announced increased payload of Electron to . The payload capacity increase was mainly due to battery advancements. The increased payload capacity allows offset of mass added by recovery technology. In addition, more payload mass could be flown on interplanetary missions and others when Electron is expended.
Fairings Rocket Lab also announced several custom fairings, including an expanded fairing (1.2x standard), a normal expanded fairing, an extended fairing and a dual stack fairing. The standard fairing has a usable diameter of 1.07 m (3,51 ft) while an expanded fairing has a diameter of 1.56 m (5.12 ft). The StriX-α mission for
Synspective in December 2020 used an extended fairing.
Autonomous flight termination systems Rocket Lab developed their own
AFTS for launches from New Zealand from Dec 2019, but for the first launch from US they used the NASA Autonomous Flight Termination Unit. == Applications ==