Aether: Roll-out of our First Actively-Stabilised Supersonic Rocket!
On the 6th of March 2017, the Aether team met the public eye as their blood, sweat and tears invested in their actively stabilised supersonic rocket is presented by Nick van den Dungen. The event itself took place at the Aula on TU Delft campus grounds. The attendees ranged from investors, to interested members within DARE.
Working on the subsystems of the rocket were the Advanced Control Team (ACT), Electronics Team, Capsule & Recovery and the Solid propulsion team.
It is important to remember that the performance of Aether is not measurable by its altitude reached but rather by the control systems ability to provide desired attitude control throughout its supersonic flight. Furthermore, Aether’s sub-systems can be broken down according to the following schematic:
ACT’s contribution to the project involved a complex canard control system in the form of their instrumentation section (IST) and active stabilisation section (ASS). These two modules communicate dependently between each other for the active control stabilisation during supersonic flight regime.
The IST module consists primarily of an XSENS IMU which provides the input data within the control system for the instantaneous current state of the rocket (i.e. accelerations & roll-rates). Following the knowledge of the state of the rocket, the ASS compares this information to the desired attitude and responds accordingly.
The ASS module itself is mechanically constrained to control only roll capabilities about the longitudinal axis of the rocket. This prevents the rocket from modifying its path in the case of a system malfunction. Furthermore, a rocket with such capability usually requires a much wider airspace and therefore poses a constraint on the launch sites in which it can operate. With the imposition of this control constraint, the launch site requirement is reduced to a 15 km range on military grounds.
The electronics team introduces their new modular flight computer. Until now, every new project within DARE required a new computer design or use of a refurbished, repurposed design from a preceding project. This is a very time consuming task and thus the team decided to make a modular and stackable design, with a standardised interface that makes the development of new modules more efficient within an effectively shorter period of time.
The capsule team will benefit from the Aether launcher by testing their new parachute deployment system for high speed flight. The conventional parachute deployment system in amateur rocketry – separating the nosecone to release the main chute — is not reliable in a supersonic launcher, where high dynamic pressure may impede the separation of the nosecone. Instead, the new system actively deploys the parachute out of the rocket from a hatch on a side using pressurized gas. In the first phase, a drogue chute decelerates the fall into the subsonic range, where the larger main parachute can be deployed. This has been successfully tested before in a Cansat class rocket, although without passing the speed of sound. The design of the parachute has also been optimized by means of wind tunnel testing to make it more stable.
The solid six provides the workhorse of the rocket: the biggest solid engine ever manufactured in our society with a propellant mass of approximately 35 kg and a physical length of 1.5m. This engine is named the ‘Asimov’ engine. One of the main features of the Asimov engine is the use of a Pertinax composite reinforced by glass fibre.
Overall the Aether team has been hard at work in the previous months and will be continuing their regime towards their eventual launch which is planned for the 29th of April. Their work hasn’t gone unnoticed, indicative by the size of the attendee list for their roll-out event. We wish them all the best for the forthcoming challenges that await them in the near future, and our fingers are crossed for a successful launch day!