The tiny Electron rocket is getting ready to fly again
After a semi-successful test, the little launch vehicle is hoping to reach orbit in their second flight.
Testing rockets is a tricky business. All it takes is for one of millions of interconnected systems and components to go wrong for things to literally go up in flames. Early American and Soviet rockets were almost as likely to blow up on the pad as they were to lift off. SpaceX’s first three launches of their Falcon 1 were failures, with the first flight lasting only around 30 seconds. With this in mind, new space company Rocket Lab’s first launch of their Electron rocket earlier this year was fairly impressive. The rocket lifted off successfully, burned its first stage for its full duration, separated and ignited the second stage. The rocket even successfully crossed the 100km Karman Line which deliniates the edge of space. Here is the video of their launch:
Unfortunately, a fault caused the rocket to stop operating four minutes into the flight at an altitude of 224km (well above the Karman Line). This means that the rocket flew a sub-orbital arc which took it into space, but was unable to gain sufficient velocity to achieve orbit. Rocketlab released a writeup of their findings about the fault in their first launch, which they called ‘It’s A Test’. The full post can be found below:
The short version of events is that their first test was largely successful, and that they shut down the rocket early because of some incorrect data retrieved by a contractor. Rocket Lab asserts that other than the misconfigured equipment, which was owned and operated by a third-party contractor, the launch was proceeding as expected. According to the post, they had a ‘a great first stage burn, stage separation, second stage ignition and fairing separation’. CEO Peter Beck said “it’s a very, very easy thing to fix. You literally tick a box in some software.”
Based on this, they announced that there are no major changes to the vehicle required and that they will begin manufacturing the next three rockets. Rocket Lab seems confident that their next test flight, some time in the next few weeks, will reach orbit.
The goal of Rocket Lab aims to make these rockets so affordable and straightforward that their launches become routine. As they state in the conclusion to their post, “at full production, Rocket Lab expects to launch more than 50 times a year, and is regulated to launch up to 120 times a year. In comparison, there were 22 launches last year from the United States, and 82 internationally.” They aim to make use of modern technologies to allow a dramatic cost reduction — eventually launching payloads for just under $5 million per flight.
The first stage of the Electron is powered by 9 Rutherford rocket engines. They’re arrayed similarly to the 9 Merlin 1D+ rocket engines on the first stage of SpaceX’s (much larger) Falcon 9. The most unique feature of the Rutherford is that, rather than burning fuel to run a turbopump to force fuel into the engine, it uses a battery powered motor to propel fuel into the combustion chamber. This allows for a simpler, lighter engine, but this has only become practical recently as battery technology improves. Additionally, the Rutherford makes expansive use of additive manufacturing, or 3D printing, to allow for the fast production of complex geometries.
The fuel tanks, which store the liquid oxygen and kerosine propellant, are made from carbon composite to minimise their weight — they claim it reduces the weight of the vehicle by 40%. This is an advancement which SpaceX is also pursuing (although at a much, much larger scale) for their Interplanetary Transport System. SpaceX has built and tested a carbon fibre tank (which could fit dozens of whole Electron Rockets inside it), although it was damaged during tesing.
The second stage of the Electron is powered by a single Rutherford rocket engine which is optimised for use in the vacuum of space. This is done by adding an extended length engine bell to direct the exhaust (this is done by the air pressure while in the atmosphere, which is why the first stage engines don’t need huge engine bells (this is a vast oversimplification)).
Smaller, lighter payloads require smaller, lighter launchers. Because of the continual miniaturisation of technology (due in part to advances in mobile phone tech), it’s becoming easier to make small, mini- or nano-satellites. A common form of these are ‘cubesats’, which are made of cube shaped units of 10cm in length and can be combined into larger (e.g. 10 x 10 x 30cm for a 3 unit cubesat) satellites, or launched individually. Cubesats are expected to be a common payload on Electron, and the vehicle can launch hundreds of them at once. Beyond Low Earth Orbit, Google Lunar XPRIZE competitor Moon Express have already paid to launch on an Electron. Below is a video on their modular lunar landing system.
Overall, Rocket Lab had a very successful first test, especially considering that the whole rocket is brand new. It’s likely that their next launch, which they’re calling ‘Still Testing’ will make it into orbit when it launches around 2 months from now.
