NEW ORLEANS, La. — NASA is one step closer to putting Americans back on the moon as the agency showed off the completed core stage of the first-ever Space Launch System (SLS) rocket — the most powerful rocket ever built.

• SLS rocket, Orion crew capsules will be used to get back to the moon
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The state-of-the-art SLS is finally ready for testing. Using both the SLS rocket and Orion crew capsules, NASA administrators say astronauts will have more access to parts of the moon they have not been able to reach in the last six missions all those years ago during the Apollo missions.

NASA Administrator Jim Bridenstine got a close-up view of everything going on as he visited a NASA assembly facility in New Orleans on Monday.

"Think of it as a reusable, in other words, a permanent command module that will be in orbit around the moon for 15 years. With solar electric propulsion so it can go to the North Pole, the South Pole, in other words the L1, the L2 point (Lagrange Points) and give us access to the entirety of the moon so that we don't miss these kinds of discoveries every again," he said.

All of this comes with a hefty price tag as the agency races to return astronauts — including the first woman — to the moon by 2024.

Each SLS rocket costs as much as $1.6 billion. However, NASA administrators say they are still in price negotiations with Boeing.

If they buy a second rocket, the price for each could drop to $800 million.

Before they put humans back on the moon, the space agency plans for un-crewed missions that will circle the moon in as little as two years.