SpaceShip Two will use its hybrid rocket motor to propel itself into space.

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The term hybrid is used because this type of rocket motor uses neither all-liquid fuel nor all-solid fuel, but a combination of both.

BBC: Hybrid success for British rocket

Dr Baker reckons that costs can be cut if the launch rocket uses the satellite's guidance computer instead of having its own, and if the satellite's built-in rocket motor is bolstered to do the work now performed by a launch rocket's upper stage.

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But that launch too was less than perfect, with technicians during the final days before liftoff deciding to trim off four feet of rocket-motor nozzle extensions with metal shears to address an unexpected problem with cracking.

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Later this year a rocket incorporating the new motor will make an attempt on the UK rocket altitude record, which stands at 10, 540 m (34, 579 ft) and is held by the Mars group.

BBC: Hybrid success for British rocket

The key is a unique motor, the Sabre, which serves as jet engine and rocket rolled into one.

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With its cluster of four Taepodong 1 engines powering the first stage, and either a similar engine or a Scud motor for the second stage, the Taepodong 2 is unquestionably a rocket to be reckoned with.

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