SpaceX is one step closer to realizing its goal of sending human explorers to Mars. The privately funded space company this week sent its next-generation rocket engine, codenamed Raptor, to a Texas facility for testing.

SpaceX President Gwynne Shotwell made the announcement at the Small Satellite Conference in Utah according to Ars Technica. A spokesperson for the space flight company also confirmed the news after the conference.

As the publication notes, the Raptor engine could be as much as three times more powerful than the Merlin engines that currently power SpaceX’s Falcon 9 and upcoming Falcon Heavy rockets. Details are scarce although founder Elon Musk has said that the Raptor could have a trust of around 500,000 pounds which puts it in roughly the same category as a main engine on a space shuttle.

Unlike the shuttle, however, that uses three main engines and two booster rockets, a future Mars Colonial Transporter would likely be powered by nine Raptor engines.

SpaceX could send an unmanned vehicle to Mars as early as 2018 with humans heading to the Red Planet as early as 2024.

Musk is expected to reveal more details regarding SpaceX’s plans to put a colony on Mars at the International Astronautical Conference which takes place in Guadalajara, Mexico, from September 26 through the 30th.