Flinders University IMU update

The Electronics for the payload unit being developed at Flinders University are now 90% built. The inertial sensor and GPS board is shown mounted on top of the PC104 single board computer. This configuration will form the payload module from Flinders University.



The build was mostly successful although a few complications occurred in the process. The gyros used are ADXRS300 parts which are only available in a 32 ball BGA part which is difficult to mount by hand without the necessary equipment. 2 of 3 were successfully placed on the first attempt using a hot air tool, the third was a failure. Another gyro is being sourced as a replacement.

The board is currently being tested and programmed to interface to the Vulcan single board computer. The single board computer is running an extended kalman filter under the eCos operating system to estimate the rockets position and attitude from the inertial data and GPS.

ASLI Rocket Team VaPak Propulsion Update

A critical milestone in for the Pathfinder 01 development program was scheduled to take place July 24th, when the newly designed liquid propellant motor was to undergo qualification firings. However last minute logistical issues required that our team postpone the planned firing, pending a new safety review.

The term VaPak has been applied to propulsion systems that utilise the vapor pressure of one or more volatile propellants, to deliver said propellants to the rocket motor. Thus negating the need for separate high pressure feed or pump systems to deliver propellants to the rocket motor, leading to greater overall simplicity and reduced cost.


Our innovative design uses a high vapor pressure liquid oxidizer (Nitrous Oxide) and standard Methylated Spirits (95% Ethanol), to provide a simple, safe and efficient propulsion system. And is based on the proven heritage of Nitrous Oxide based hybrid rocket developments of the last 10 years.

Potential hazards associated with other forms of propulsion are largely eliminated due to the following.

1/ Nitrous Oxide is loaded remotely with operators more than 50 meters from loaded flight tank.

2/ There is no explosive or toxic agents used, and ignition is only possible via the introduction of oxygen gas and high voltage spark. This is again facilitated remotely from a safe distance.

3/ Nitrous Oxide is non-toxic except for slight narcotic effect (Laughing Gas), as to is Ethanol.



Above is the motor hardware showing the outer casing, injector, phenolic chamber liner and nozzle housing closure.

The team did complete critical testing of the Nitrous Oxide Fill & fire system and the static test stand assembly, and are ready for rescheduling of qualification trials.

Flinders University Team Update

The Inertial Measurement Unit (IMU) being designed for the rocket consists of 3 single axis MEMS rate gyros, 2 dual axis accelerometers, 2 dual axis magnetic sensors and a GPS unit. The magnetometer and the GPS provide absolute heading and position reference to minimize accumulated error in the inertial measurements. The IMU has been designed together with a CAN bus expansion module on a PC104 form factor. The base board has two smaller boards connecting at right angles to provide inertial sensing in all 3 axis. This board will be mounted on top of a PC104 XScale based single board computer(SBC) interfacing via two high speed UARTs (one for CAN bus, one for IMU). The board design has been completed and all components have been source courtesy of RS Components.



The eCos real-time operating system has been ported to run on the Arcom Vulcan board sponsored to the project by RS Components. eCos is a deeply embedded operating system designed for applications requiring fast deterministic response time.

Currently a Kalman Filter implementation is being to developed to run on the SBC along with a roll control algorithm to drive the discontinuous reaction jets.