Daft Punk must have invaded the ears of NASA staff when planning for the Space Launch System rocket, taking, “Harder, Better, Faster, Stronger” to heart.

The SLS has been constructed for the first mission of (hopefully) many to chase ambitions of deep space travel, and once completed, it will claim the title as the most powerful rocket in the world. In a video released Monday, NASA explains how assembling the pieces constructed across the United States presents engineers with a dizzying challenge.

9.2 Million Pounds of Thrust

Wielding four RS-25 engines and two solid rocket boosters, the SLS rocket produces a massive 9.2 million pounds of thrust, providing 15 percent more power than Saturn V, the last rocket powerful enough to take humanity to the moon.

Two million of those pounds comes from the four RS-25 engines, each of which is as big as a car. They run on supercooled hydrogen and oxygen, producing swathes of steam, but burning clean. One of the engines, E2045, took John Glenn on his final mission to space, STS-95. But two solid rocket boosters — each 17 stories tall, overshadowing the Statue of Liberty herself — provide the bulk of the power, at 3.6 million pounds of thrust each.

core stage forward skirt
One of many pieces of the SLS's core stage, the forward skirt will house many flight computers, which have been designed to withstand the hazards of launch.

Clocking in at 270,000 pounds and 212 feet long, the core stage of the SLS is not only the largest rocket constructed by NASA, but it’s also taller than the Leaning Tower of Pisat.

A Big Project Needs a Big Workshop

To construct such a ginormous vehicle, NASA uses a staggeringly large space: the dryly named Vehicle Assembly Building (VAB), which, at 525 feet tall, holds the record as the tallest single-story building in the world. And with such a large space, everything takes a little bit longer: The 456-foot-tall doors take approximately 45 minutes to open or close completely.

Before the SLS can be assembled, though, all the parts must be brought together since individual parts are constructed across the country. Northrop Grumman builds segments with fuel and motors for the rocket boosters in Utah, while Boeing constructs the core stage at NASA’s Michoud Assembly Facility (MAF) in New Orleans.

NASA schedules some pieces for intermediate stops. For example, once constructed, the core stage will travel to NASA’s MAF, then the Stennis Space Center in Mississippi. “We practice lifting it into the test stand where NASA will fire the whole stage with all four engines,” NASA Public Affairs Officer Tracy McMahan tells Inverse. If all goes well, the core stage will return to the Vehicle Assembly Center for fit checks.

The VAB itself hosts the grand finale, where cranes will stack the hardware together.

Putting It All Together

The three-stage final assembly starts with a digital simulation of the assembly, followed by a practice round with a replica before NASA constructs the actual rocket. NASA may keep the replica or loan it to a museum when its duties are done, McMahan explains. Crane operators in High Bay 3 will coordinate the rocket’s construction from above, ready with remote brakes in case of an emergency.

VAB view from the floor
The view from the floor of the Vehicle Assembly Building at Kennedy Space Center. Crane operators will oversee the construction of SLS from above.

After pushing the original launch date in 2018 back to 2019, NASA has the launch of EM-1 slated for June 2020, kicking off the uncrewed Orion capsule’s 25-and-a-half-day mission to travel to the moon and back. Hopefully, with NASA’s massive effort comes massive success.