NASA today  announced its plans today for the design of an enormous new rocket, which it hopes will be the one to make the next great leap in space exploration — taking astronauts to Mars.

“The Space Launch System will give the nation a safe, affordable and sustainable means of reaching beyond our current limits and opening up new discoveries from the unique vantage point of space,” NASA said in a statement on its website.

NASA’s tentative timeline is to launch the first unmanned test flight in 2017, a flight with a crew in 2021, an astronaut flight bound for an asteroid in 2025 and trips to Mars sometime in the 2030's.

The project’s current estimated cost is $18 billion over the next five years, but some speculate that the cost could actually double that estimate.

The new shuttle will be more powerful and have the capability to travel farther than any rocket before, thanks in great part to its main use of liquid hydrogen and oxygen rockets as opposed to solid rockets.

The recently retired space shuttle mainly used solid rockets, which are cheaper than liquid but cannot be stopped once they are lit. A flaw in a solid rocket caused the Challenger accident in 1986. By contrast, liquid rockets can be stopped after they’re lit and are more similar to the Apollo spacecraft NASA used in the 1960s and ’70s than the recent shuttles.

“This launch system will create good-paying American jobs, ensure continued U.S. leadership in space, and inspire millions around the world,” NASA Administrator Charles Bolden said. “President Obama challenged us to be bold and dream big, and that’s exactly what we are doing at NASA. While I was proud to fly on the space shuttle, tomorrow’s explorers will now dream of one day walking on Mars.”

NASA’s next challenge is a political one. It has historically struggled to survive changes in presidential administrations and congressional changes, so next year’s election may play an important role in the fate of this ambitious new rocket.

Additional reporting by ABC News’ Gina Sunseri and the Associated Press.