The testing campaign for NASA's super big, super expensive Space Launch  System is now complete, the agency declared on Friday. All that's left  now for the rocket is launch the Artemis I demonstration mission to the  moon 

the first in a long line of planned missions to eventually return humans  to the lunar surface by the middle of the decade. The launch could  occur as soon as late August, NASA officials said. 

The agency will roll the 322-foot-tall rocket and Orion spacecraft back  to the Vehicle Assembly Building, an assembly hangar at NASA's Kennedy  Space Center, on July 1 or 2 

where both will be prepared for launch. From there, the agency will have  roughly six to eight weeks of work before what should be the final  roll-out, John Blevins 

chief engineer of the Space Launch System Program, said Friday. 

Once SLS is back on the launch pad, officials would spend around 10-14  days preparing for liftoff, Cliff Lanham, senior vehicle operations  manager for exploration ground systems, added. 

NASA declared the "wet dress rehearsal" (WDR), as the slew of tests is  called, complete despite a hydrogen leak issue that caused launch  controllers to halt the countdown at T-29 seconds 

The leak was detected in the hydrogen bleed line during the propellant  loading process, when hundreds of thousands of gallons of cryogenic  liquid oxygen and liquid hydrogen were being loaded into the tanks. 

But despite the leak issues, the agency was able to load both rocket  stages' tanks with propellant, then drain them — major testing pieces  that the agency had yet to put into place. 

While officials did not give an exact launch date, Tom Whitmeyer, deputy  associate administrator for common exploration systems development,  said things are looking good for an end of August timeframe. 

While officials did not give an exact launch date, Tom Whitmeyer, deputy  associate administrator for common exploration systems development,  said things are looking good for an end of August timeframe. 

"We feel getting through the wet dress was a major milestone for us," he  said. "It gives us some confidence that we're still on a good path." 

The inaugural launch of SLS this year would be 12 years in the making.  It was originally envisioned by Congress and NASA as a replacement to  the Space Shuttle. 

It is now designated as the launch system that will eventually return  humans to the moon -- no small honor, all things considered.