NASA is recycling Space Shuttle engines for a very important purpose

Right now, NASA is building a monster rocket to shuttle astronauts to Mars called the Space Launch System, or SLS.

When finished, this rocket will be able to launch up to 2.16 million pounds into space. That kind of weight requires a powerful engine - four of them, to be precise.

NASA will use four RS-25 engines - along with two rocket boosters - to get the SLS from ground to space and on its way to Mars. Combined, the engines and boosters will make the SLS the most powerful rocket ever built, which is what you want when you're trying to travel farther than any human has dared to before.

These engines powered the Space Shuttles and a modified version of them will now usher us into the next generation of space exploration.

Learn more about these impressive feats of engineering in the graphics to follow: