NASA has announced that the rocket that will eventually take humans to Mars, the Space Launch System (SLS), has successfully completed the critical design review phase, meaning NASA can begin construction.
The SLS will be the most powerful rocket ever built, with NASA saying it will "launch America into a new era of exploration to destinations beyond Earth's orbit."
The critical design review is the last of four reviews before construction can begin for the Block 1 configuration. There are two more block configuration upgrades to be added on later, but all stages will include the core stage and engines.
The next step will be the design certification, scheduled for 2017 after manufacturing, integration and testing of the components is complete.
"We've nailed down the design of SLS, we've 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," said NASA's Bill Hill, deputy associate administrator of the exploration systems development division.
"There have been challenges, and there will be more ahead, but 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."
The SLS will be powered by two boosters and four RS-25 engines, and along with NASA's Orion spacecraft, it will go through a final flight readiness review before the scheduled 2018 flight readiness date.
The core stage of the SLS will be about 200 feet tall, with a diameter of 27.6 feet, and will carry cryogenic liquid hydrogen and liquid oxygen fuel for the rocket's engines.
Image credit: NASA and NASA/MSFC