A supersonic rocket designed by University of Canterbury mechanical engineering student Lachlan Matchett was successfully launched at 10.31am on Saturday at Kaitorete Spit, near Lake Ellesmere.
"It was out of sight and into the clouds after three and a-half seconds.
"It was supersonic 2.4 seconds after it left the launch pad.
"You could hear the sonic boom," Mr Matchett (21) said yesterday.
The 2.3m rocket named Sarah was believed to have reached 2200kmh, short of the hoped-for speed of mach 2 (2450kmh).
The rocket's recovery system failed when a shock cord connecting the parachute broke.
"The disconnected parachute and spot GPS tracking system drifted for an hour and a-half, before landing 12km northeast of the launch site, at the base of the Port Hills," Mr Matchett said.
"We didn't get the rocket back ... I suspect it's on the bottom of the sea.
"It would have been doing 700kmh when it hit the sea and would have disintegrated on impact."
While data cards on the rocket were not recovered, Mr Matchett said the project had met some of his objectives.
"It was a success overall.
"The goals of the project were to create a launch site for a rocket of this size, develop a rocket to safely and efficiently travel faster than the speed of sound and develop a reliable and robust recovery system."
The Civil Aviation Authority sanctioned the launch and had closed the airspace above the launch site.
The launch will be shown on TV3 News tonight.
