Rocket Lab’s Electron conducts inaugural flight from New Zealand

by Chris Gebhardt

The U.S.-based Rocket Lab corporation has entered the commercial launch market with the maiden flight of its Electron rocket on Thursday morning (UTC).  The small-scale launcher will cater to the small satellite market, with low-end million dollar flights and its revolutionary engine design launching from the Māhia Peninsula from the North Island of New Zealand’s eastern coast. The rocket managed to get to space, albeit not to orbit.

Rocket Lab – expanding the small-sat launch market:

Rocket Lab, a U.S.-based launch service provider with a New Zealand subsidiary, becomes the newest entrant into the world’s launch market with the maiden voyage of its Electron rocket.

The 10-day launch window for Electron’s maiden flight opened at 09:00 NZDT (New Zealand Daylight Time) on Monday, 22 May.

The time offset for New Zealand is UTC+12, placing the opening of the launch window at 21:00 UTC on Sunday, 21 May (which is 17:00 EDT on the eastern seaboard of the United States on Sunday afternoon). However, due to poor weather, the launch was delayed twice to Thursday morning. Launch finally took place, with a nominal ride to space, in the early hours of Thursday morning UTC.

“It was a great flight. We had a great first stage burn, stage separation, second stage ignition and fairing separation. We didn’t quite reach orbit and we’ll be investigating why, however reaching space in our first test puts us in an incredibly strong position to accelerate the commercial phase of our programme, deliver our customers to orbit and make space open for business,” said CEO Peter Beck.

Overall, Rocket Lab’s mission is to offer “lightweight, cost-effective commercial rocket launch services” to the small satellite market.

Much like Vector Space – which is currently in small scale suborbital testing with aims to enter the launch market next year – Rocket Lab caters to much the same market, offering small satellite users a dedicated launch system to eliminate ride-sharing requirements on the larger, more established launchers.

According to the company’s website, Rocket Lab lists its launch services with Electron as costing $4.9 million (USD) per flight.

Rocket Lab’s journey to its inaugural orbital launch began 11 years ago with the company’s founding by Beck, a citizen of New Zealand.

The company’s first foray into rocket flight occurred three years after the company’s founding with the launch of the Atea-1 suborbital sounding rocket.

The Atea-1 stood 6 m (20 ft) tall, weighed 60 kg (132 lbs) at liftoff, and was capable of carrying at 2 kg (4.5 lbs) payload as high as 120 km (74.5 mi).

The first and only flight of Atea-1 occurred on 20 November 2009 at 14:30 NZDT from Great Mercury Island near the Coromandel Peninsula in New Zealand.

Liftoff came more than seven hours behind schedule after issues with the rocket’s fueling presented during the count.

At the time of launch, Rocket Lab claimed that the Atea-1 had reached the internationally recognized boundary to space – the Kármán line, at an altitude of 100 km or 62 miles; therefore, Rocket Lab had become the first company in the Southern Hemisphere to reach space.

Unfortunately, as the Atea-1 had no telemetry downlink, was not tracked by ground-based assets, and was not recovered, its maximum altitude during its only flight is unknown and it is not possible to verify the claim that it reached space.

Regardless, the test was considered a success, and Rocket Lab – while not flying a second Atea-1 rocket – proceeded into development of their Electron rocket.

The following year, in 2010, Rocket Lab was awarded the Operationally Responsive Space Office (ORS) contract from the U.S. federal government – initiating a formal study into the feasibility of a low-cost launcher system for nanosatellites.

Development and production of the Electron rocket occurred with relatively few hiccups, with an initial target first test launch of 2015 only slipping to 2017 (something that is quite impressive on the orbital rocket stage).

Specifically, one of the major issues faced during development was with the location of the originally desired launch site.

Rocket Lab Launch Complex 1 – Māhia Peninsula:

To accommodate its customer needs, Rocket Lab developed a dedicated launch facility on the east coast of New Zealand on the Māhia Peninsula of the North Island.

Officially opened on 26 September 2016, Rocket Lab Launch Complex 1 had initially been planned for construction on Kaitorete Spit on New Zealand’s South Island near Canterbury before construction negotiations stalled and Rocket Lab moved the launch site to the North Island and the Māhia Peninsula.

The selection of the Māhia Peninsula was actually more favorable from a geographic consideration as it permits a wide range of available orbital inclinations to launch into – with various Sun-Synchronous Orbit (SSO) flights to various inclinations ranging between 39 and 98 degrees available.

The Māhia Peninsula – New Zealand’s first orbital launch site – also offered less interaction with standard aviation routes, allowing the site to be licensed for up to 100 flights per year with a maximum flight rate of one launch every 72 hours.

Very similar to the facilities and architecture utilized by SpaceX for their Falcon 9 rocket, Rocket Lab built a launch complex for its Electron rocket featuring a pad with a 50-tonne launch platform and tower, storage tanks for propellant and oxidizer, and a hanger where the Electron rockets and their payloads will be integrated prior to transport to the pad.

Unlike SpaceX, however, which transports its Falcon 9 rocket horizontally to the pad resting on top of the Transporter/Erector/Launcher (TEL), Rocket Lab inverts that process, horizontally transporting the Electron underneath its TEL.

As with launch locations in the United States, Rocket Lab Launch Complex 1 is located on a remote area of land within New Zealand – providing increased safety and a natural barrier to curious humans.

Regardless, for the initial series of three test flights, Rocket Lab expects to use an 8 km (5 mi) exclusion zone around the pad for safety considerations with that zone reducing in size once operational launches begin.

The Mission Control Center for Electron and Rocket Lab is centered in Auckland, New Zealand – approximately 500 km (310 mi) to the northwest – and will allows the Rocket Lab teams to monitor more than 25,000 data channels during the countdown and launch.

Electron – gearing up for first orbital campaign:

At the centerpiece of Rocket Lab’s campaign to the smallsat market is the company’s ability to provide dedicated launch services for small satellite manufacturers and users, freeing them from their ride-share tether to larger vehicles.

Currently, smallsat users are beholden to the massive medium and heavy lift rockets – like Falcon 9 and Atlas V – for rides to orbit.

The issue with ride-share is that while it offers access to space, that access is limited and the smallsat companies have no control over the precise orbit they are deposited into – as they can only go to the orbit the primary satellite customer has paid for.

Sometimes, the orbital destinations of the primary satellites match the smallsat ride-along users’ needs. Often times, however, the primary orbital destination is “good enough” but not ideal, and the smallsat user simply has to accept that because there is no other option for access to space.

That is about to change.

Rocket Lab’s Electron rocket now seeks to be the first commercially available launcher to cater to the commercial smallsat market.

In all, the Electron stands 17 m (56 ft) tall, has a diameter of 1.2 m (3 ft 11 in), and carries a fully-fueled mass of 10,500 kg (23,100 lbs).

The first stage uses a cluster of 9 Rutherford electric engines, burning RP-1 (refined kerosene) and LOX (Liquid Oxygen), that provide a combined 34,500 lbs (15,649 kg) of thrust at liftoff – increasing to 41,500 lbs (18,824 kg) of thrust in a vacuum.

The first stage engines have an Isp (Specific Impulse) of 300 seconds in a vacuum.

The second stage’s single Rutherford vacuum-optimized engine – also burning RP-1 and LOX – will provide 5,000 lbs (2,268 kg) of thrust and has an Isp of 327 seconds.

The rocket is capable of placing a 150 kg (330 lb) payload into a 500 km (310 mi) SSO.

The first Electron rocket, named “It’s A Test” was transported to the launch pad earlier this month and successfully completed a full up Wet Dress Rehearsal (WDR) on 16 May.

For “It’s A Test”, the rocket will be tasked with entering an 83 degree elliptical orbit of 300 x 500 km.

Once the rocket lifts off, it will represent the first orbital launch attempt by a commercial company from a fully commercial launch site.

Despite launching from New Zealand, the U.S. Federal Aviation Administration (FAA) had to issue the U.S.-based company its launch license for “It’s A Test”.

Following the successful 16 May WDR, the FAA issued the launch license on 17 May.

The Rutherford electric engine – the first of its kind:

Unique to the Electron rocket is its electric pump-fed Rutherford engine.

Designed in-house and specifically for the Electron, the first-of-its-kind engine – named after New Zealand scientist Ernest Rutherford – is a small, liquid-fueled engine capable of producing a maximum thrust of 5,000 lbf (22 kN) in a vacuum.

For the Electron rocket, each core stage Rutherford engine will produce a little more than 3,800 lbf at liftoff, increasing to slightly more than 4,570 lbf as the rocket ascends into the vacuum of space.

By contrast, the vacuum-optimized Rutherford on the second stage will produce the engine’s maximum 5,000 lbf.

The engines themselves are constructed largely through 3D printing, specifically through electron beam melting, with its main prop valves, injectors, pumps, and engine chambers all 3D printed.  The entire engine printing process takes just 24 hours.

The unique electric design replaces the high pressure gasses used in gas-generator cycle engines with an electric motor – reducing the overall weight and increasing the efficiency of the engine.

Specifically, a rotodynamic pump will use a rotor to continuously impart energy (increase the pressure) onto the fuel and oxidizer as they flow down from their propellant tanks into the fuel and oxidizer pumps.

The electric rotodynamic pumps will spin at 40,000 rpm and increase the fuel and oxidizer pressures from between 0.2 and 0.3 MPa (29 to 44 psi) to between 10 to 20 MPa (1,500 to 2,900 psi).

The pumps on each engine will be actuated by a brushless DC electric motor – fed by a Lithium polymer battery bank – that is powered by DC (Direct Current) electricity via an inverter/switching power supply which produces the Alternating Current (AC) that then drives the various phases of the motor via a closed loop controller.

At engine start up, LOX will flow from its propellant tank into the electric oxidizer pump, from which it will travel directly into the engines’ combustion chambers.

The RP-1 will likewise drain from its propellant tank into the electric fuel pump; however, it will first be directed through heat exchange tubing down the outside of the engine nozzles before travelling back up into the combustion chambers, where it will meet the LOX.

Use of this kind of electric motor system produces a 95% efficiency as compared to the 50% efficiency achieved through standard gas-generator cycle engines.

(Images: Rocket Lab, Google Maps)

Related Articles