For the first time in almost 40 years, NASA has completed all steps needed to clear a critical design review (CDR) for the most powerful rocket ever built that will take humans to deeper space missions, including Mars.

The agency's Space Launch System (SLS) is the first vehicle designed to meet the challenges of the journey to Mars and the first exploration class rocket since the Saturn V.

SLS will launch America into a new era of exploration to destinations beyond Earth's orbit.

"We have successfully completed the first round of testing of the rocket's engines and boosters and all the major components for the first flight are now in production," explained Bill Hill, deputy associate administrator of NASA's Exploration Systems Development Division.

"This review gives us confidence that we are on the right track for the first flight of SLS and using it to extend permanent human presence into deep space," he added.

This review is the last of four reviews that examine concepts and designs.

The next step for the programme is design certification, which will take place in 2017 after manufacturing, integration and testing is complete.

The design certification will compare the actual final product to the rocket's design.

The final review, the flight readiness review, will take place just prior to the 2018 flight readiness date.

"This is a major step in the design and readiness of SLS," added John Honeycutt, SLS programme manager.

The core stage of SLS, towering more than 200 feet tall and with a diameter of 27.6 feet, will carry cryogenic liquid hydrogen and liquid oxygen fuel for the rocket's four RS-25 engines. NASA recently completed the first developmental test series on the RS-25 engines.

The SLS five-segment Solid Rocket Motor undergoes a static test fire at the Orbital ATK facility in Promontory, Utah, in this handout photo provided by NASA, March 11, 2015.