Jetblack, the New Zealand-based group aiming at a 1600km/h swing at the world land speed record, has given up on the jet and rocket combo of its earlier design.
A new aero and propulsion design has been unveiled that will set the flying Kiwi on track to take on the British Bloodhound SSC attempt at the same 1000mph record, this time based on two hybrid rocket motors.
"The work the group's design team has undertaken over the past 12 months has resulted in a car that is less complex, produces considerably less drag, has greater controllability and the potential to achieve the target speed more quickly," said Jetblack founder and managing director Richard Nowland.
"In all, this is a significant advance over its predecessor.
"There are two main points of difference with the new design. The first is the move to solely rocket propulsion using two hybrid rocket motors currently under development with our propulsion partners Space Propulsion Group in California.
We established the relationship with Space Propulsion Group, who a world-leaders in hybrid rocket propulsion, in 2011."
The hybrid rocket system was chosen as it's considered safer than other propulsion systems.
Space Propulsion Group president Dr Arif Karabeyoglu explains, "SPG's advanced hybrid rockets deliver very high performance while retaining the safety, simplicity and controllability of classical hybrids. The inherent safety, throttling and shut down are the key virtues of SPG's rocket technology which makes it ideal for this particular application."
SPG is developing a hybrid rocket propulsion system that can be throttle controlled, allowing rocket thrust to be varied - a significant breakthgrough in safety and, hopes Nowland, a competitive edge for the Jetblack attempt.
The new rockets will produce 35,000lb of thrust each, nearly double the 20,000lb each that the prior machine was capable of.
Where jet engines require an air intake, the rocket propulsion system carries all fuel and oxidiser needed for the attempt - and has a huge influence over aerodynamic design and the vehicle's structure, which is now shorter by three metres, and weighs around 2000kg less. During a high speed run, the new Jetblack will shed around 3100kg - around 40 per cent of its total weight.
The Jetblack team will select a suitable venue for testing over the coming year and will begin the vehicle build next year. Low speed testing will kick off in 2014, with high speed tests and the actual challenge over the following two years.
The current land speed record is 763mph and was set by Great Britain's Thrust SSC in October 1997 at Black Rock Desert in Nevada.