You don't really think of water bottle rockets as being all that powerful; they're just a child's play toy, right? In the hands of researchers at the University of Cape Town they're not. They recently shattered the world record for a water bottle launch by sending one soaring half a mile into the air.
The exact height of the launch was 830 metres (actually the mean altitude of two back-to-back flights) which shattered the old record of 623 metres set by a U.S. team back in 2007.
To clarify, there were no explosives or combustible fluids used to propel this rocket in any way. All it had onboard was H20, air, and lots and lots of pressure. The rocket towered just shy of nine-feet tall to maximise its payload capacity, but thanks to the use of carbon fibre it only weighed just over 1.3kg.
At launch the rocket produced some 544kg of thrust, enough to get a small car completely off the ground, and in less than half a second it reached a top speed of over 547 km per hour. In other words, even though it was powered by nothing but water pressure, it was far from being a child's play toy anymore. So how long will this record stand? [University of Cape Town via Slashdot]