Space debris made news on March twelfth when a part of an old rocket motor about ten centimeters in size threatened the International Space Station.

VOA: special.2009.04.01

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.

ECONOMIST: Space

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

FORBES: Out Of This World: Space, The Final Frontier

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