The rocket men
Blink and you'd miss it. A small supersonic rocket launch is spectacularly fast, gone in a whip-crack vertical sprint and leaving behind a column of wispy exhaust drifting in a calm Canterbury sky.
For University of Canterbury engineering students George Buchanan and David Wright, every launch such as this is a spectacular finale to months of effort. Working with senior lecturer Dr Chris Hann, David has personally made four rocket airframes to date, while George devotes his research to what goes inside each one - GPS systems, controls and other software. He is working on a PhD geared to continuously calculating ideal trajectory paths.
"It is so much fun working on rockets. Every launch is a thrill," George says. "From a professional point of view, the challenge lies in the difficulty of controlling these smaller rockets; everything happens so fast. Traditional development and testing methods are expensive, running into millions of dollars, but with the new controls being done here, we can launch and it works at least as well or better than ones that have taken years to develop.
"Smarter maths is the key. It just allows us to do the control system side of it much, much faster. It has the potential to be portable to other areas, too."
Last December, the pair made a bid to break a New Zealand altitude record of 1117 metres for a specific class of rocket motor via a launch from Kaitorete Spit on Banks Peninsula. Unfortunately, a rare transmitter failure after the launch meant they were unable to recover the rocket and its data, so were unable to determine whether the record had been broken.
They are soon to try again. Another altitude attempt is planned for late winter, before David leaves to study aerospace engineering at Stanford University in the United States. It will be another small rocket, about 600mm tall, only "optimised" to go even faster and higher.
"This new one will travel at around 1700 kilometres an hour and we're expecting it to get to an altitude of four to five kilometres," David says.
A small rocket frame such as this takes several months to make. David is close to finishing a much bigger rocket to support research into control systems. By global standards, it is still small, at 1.8m, but the work involved is considerably greater and assembly began last February.
Each rocket is topped with a fibreglass cone, finished with heat-resistant paint, and carries a parachute inside. The control mechanism inside the main body of the rocket is contained on a complex circuit board. Delivering just the right amount of acceleration on take-off is a punchy solid fuel, ammonium perchlorate.
David dreams that one day New Zealand will have its own space industry, launching its own satellites. Currently, there is only one major aerospace company on the scene, Auckland's Rocket Lab. An undergraduate rocketry course offered at the University of Canterbury for the first time this year will give a new generation of students a taste of what the future might hold.