spacexElon Musk is serious about his Mars dream and is working hard to achieve it.

SpaceX has started testing an engine that is eventually expected to go to Mars. The goal is to send a rocket to Mars in 2018, making it the first private company to ever reach another planet.

The new rocket has been named Raptor and is three times as powerful as Merlin, the current engine that powers the Falcon 9 rocket. It will have 230 metric tonnes of thrust (about 250 tons), which is about the same as the main engines of the space shuttle.

A cluster of nine of these rockets will be used on the Mars Colonial Tranporter.

SpaceX President Gwynne Shotwell made the announcement that the company has shipped the Raptor to its testing facility in McGregor, Texas, at Small Satellite Conference.

CEO Elon Musk has previously revealed that his motivation for starting the company was to start a human colony in Mars. It is however unclear what exactly the 2018 mission is supposed to accomplish.