A giant metal frame standing several yards wide rises up nearly 200 feet inside the Michoud Assembly Facility, NASA's massive 832-acre space park outside New Orleans. "What you're looking at is the largest welding system in the world," said Jackie Nesselroad. She is leading a team from Boeing that's welding together the world's most powerful rocket, the Space Launch System. "It's about the coolest job on earth." SLS is not a rocket that will be reusable, like the one Jeff Bezos' Blue Origin just landed for the second time in a row. It is not a system like the one that Elon Musk's SpaceX contracts out to NASA for ferrying supplies to the International Space Station. Instead, the SLS has one customer and one mission: to take Americans into deep space.



Mars is a million times further away than the space station. It's all about discovery. There isn't a pot of gold at the end of the rainbow, so to speak. Paul Wright senior manager, Boeing

The goal is Mars. The program will cost billions. "It is designed for beyond low-Earth orbit exploration with humans," said Frank McCall, the deputy program manager from Boeing who called SLS "a mission that is long overdue." The first unmanned test flight is slated for late 2018. By 2021, the rocket is supposed to carry astronauts aboard the Orion space capsule built by Lockheed Martin. "The first crewed mission … will be a mission that goes to the far side of the moon, literally farther than we've ever gone before in manned spacecraft," said NASA SLS manager Patrick Whipps. This year alone, Congress is giving NASA $2 billion for SLS, and much of that funding is going to the core rocket built by Boeing. That core includes powerful liquid hydrogen and oxygen fuel tanks, which will give the first version of the rocket 8.5 million pounds of thrust. "That's 31 747s at full power," said Boeing engineer Tony Castilleja. That thrust will be even greater in later versions. It also makes SLS the most powerful rocket in history. "This is the only rocket that can cut the time in half and double the science and double the exploration."

An artists rendering of Boeing's most powerful rocket, the Space Launch System or SLS. Source: Boeing

Why does NASA have to pay so much, and why does it need to own the rocket? Musk has plans to get to Mars on his own, so why not just ride along with SpaceX? NASA management believes deep space exploration is so big, so expensive, so fraught with risk, that it needs to own the mission. "Mars is a million times further away than the space station," said Paul Wright senior manager for test and evaluation at Boeing. "It's all about discovery. There isn't a pot of gold at the end of the rainbow, so to speak." At least not yet.

The good news for Boeing and NASA is that Americans are once again infatuated with space. The credit goes to everything from the bold visions of billionaires like Musk and Bezos to films like "The Martian." Congress voted to give NASA a raise in 2016 to $19.3 billion — more than the agency requested. The SLS program is hoping for continued funding to pay for more trips, because beyond the first two missions, the way to Mars isn't clear. Perhaps the rocket system could take astronauts back to the moon, or to an asteroid. It all depends on how the first two missions go, how much it costs, and what other competing priorities there are through 2035. Boeing is trying to keep costs down (relatively speaking) by reusing technologies from the space shuttle programs, such as the engines and solid-fuel rocket boosters. McCall doesn't see that as looking backward. "Why reinvent the wheel if the wheel works?"

NASA is also exploring new technologies for the program down the road, such as using nuclear energy to take the Orion capsule all the way to Mars. NASA's Whipps said astronauts will also need new spacesuits. Instead of wearing suits for a few hours a day on spacewalks outside the space station, "we'll be using the spacesuit literally every day, sometimes many hours every day, on the surface of Mars or an asteroid." The suits will have to be stronger, and astronauts will need the tools to repair them on site. "When you're 40 or 60 million miles away from your home planet, there is not a depot to take parts back to," Whipps said. For now, however, the focus is building the rocket, making it lighter, and keeping the SLS program on budget and on time. The core rocket will be unpainted to save on hundreds of pounds of white paint that was only for cosmetic purposes. Boeing has revamped the welding facility at Michoud to create welds that weigh less, and it's reduced the number of tools needed from two dozen during the Shuttle program to only six or seven for SLS.

A giant metal frame standing several yards wide shoots up nearly 200 feet inside the Michoud Assembly Facility, NASA's massive 832-acre space park outside New Orleans. Source: Boeing

Meanwhile, at the Marshall Space Flight Center in Huntsville, Alabama, NASA is spending $76 million this year to build two new towers where Boeing will test the fuel tanks. The liquid hydrogen tank alone will stand 130 feet, and testing could begin later this year. "The biggest challenge for us is we are going to be doing all these tests — the engine test, the liquid hydrogen tank, the inner tank and the liquid oxygen tank, almost all at the same time," said Boeing's Wright. Those tests ultimately will determine the rocket's limits. "We're going to qualify those by testing all the way to failure," said NASA's Tim Flores. For him, knowing the rocket's limits, and making sure SLS is safe, has gotten personal. His 11-year-old son recently decided he wants to be an astronaut when he grows up, and Flores believes someone his son's age will be the first human on Mars. "Now I think, 'Am I making the right decisions with the things that I'm doing?'" he said, standing atop a test tower in Alabama. "My son might actually be on one of those flights."