After years of setbacks, NASA’s SLS moon rocket is ready to fly

August 27, 2022 at 6:00 a.m. EDT
The Artemis I Orion capsule sits atop the Space Launch System (SLS) rocket on Launch Pad 39B as NASA prepares to send Orion to circle the moon. (Jonathan Newton/The Washington Post)
13 min

CAPE CANAVERAL, Fla. — The rocket was late, again. The initial launch date, the end of 2016, was long gone. And in the spring of 2019, Jim Bridenstine, the NASA administrator at the time, was told it’d be another year or more before NASA’s Space Launch System would be ready.

He was furious and threatened to replace the rocket with one built by the fast-growing private space sector, such as SpaceX. But Bridenstine’s attempt to bench NASA’s rocket was quickly rebuffed by the powerful interests, including Sen. Richard C. Shelby (R-Ala.), the chairman of the appropriations committee. Those interests had shepherded the SLS through thickets of controversy since its inception more than a decade ago.

Now, after years of cost overruns and delays, damning reports by government watchdogs and criticisms from space enthusiasts and even parts of NASA’s own leadership, the SLS endures, as only a rocket built by Congress could.

Today, it stands on Launch Pad 39B at the Kennedy Space Center, towering at 322 feet, taller than the Statue of Liberty. NASA is scheduled to make its first attempt to launch Monday at 8:33 a.m., a test flight that is meant to propel the Orion crew capsule, without any astronauts on board, into orbit around the moon. A successful launch will mark a major milestone in NASA’s quest to return astronauts to the lunar surface under its Artemis program.

NASA officials have stressed that this is a test, a mission known as Artemis I designed to see how the vehicle performs before they load astronauts onboard. That could happen as soon as 2024, when astronauts would orbit, but not land on, the moon. A landing could come in 2025 or 2026.

Some 100,000 people are expected to jam the Florida Space Coast for the launch, excited to watch NASA write a new chapter in the history of human space exploration. But even if the flight goes off as scheduled, NASA officials warned that there could be surprises that force them to go off-script.

“In all of our excitement, I want to remind people this is a test flight,” NASA Administrator Bill Nelson said in an interview. “We’re going to stress this thing in a way that we would never do with humans on board. And so I just want to bring everybody back to reality.”

Not only has the rocket never flown, but NASA has struggled with all sorts of challenges in the tests designed to prepare the rocket for flight. Sensors detected a problem with the hydraulic systems that help steer the rocket, cutting short an engine test last year. Earlier this year, a fueling test and a simulated countdown were marred by a hydrogen leak and a faulty valve, among other issues.

Then again, there is nothing simple about the SLS, a huge, complicated beast that holds 700,000 gallons of supercooled liquid hydrogen and liquid oxygen. It has four first-stage engines and two solid-fuel side boosters. The avionics computers in the rocket have miles upon miles of cabling and more than 500 sensors. At liftoff, it weighs 5.75 million pounds.

The Artemis I mission is scheduled to last 42 days 3 hours 20 minutes, sending the Orion spacecraft on a round trip mission that would reach 40,000 miles beyond the moon and travel a total of 1.3 million miles.

But in a way, the odyssey to get to this point has been even more arduous — an at-times painful path that shows how Washington works, and, ironically, why NASA has been unable to return to the moon since the last of the Apollo missions 50 years ago.

Standing atop its launchpad, the SLS is a glorious sight, but also a contradiction. More powerful than the Saturn V that launched the Apollo astronauts to the moon, the SLS is a symbol of engineering prowess and American might that evokes the 1960s-era exploration nostalgia. But costing more than $23 billion, it also is a monument to parochial congressional interests, stultifying bureaucracy and contractor mismanagement.

And as the commercial sector continues to develop new rockets, the future of the SLS is unclear.

As Casey Drier, chief advocate and senior space policy adviser at the Planetary Society, recently asked in an essay, “Given its cost, the existing launch capabilities provided by private companies such as SpaceX, Blue Origin and RocketLab, and the real progress of super heavy-lift private rockets, why does the SLS still exist?”

Artemis 1: New booster with

a big mission

NASA’s new rocket will use “legacy” hardware — meaning, largely left over from the space shuttle program — to launch the uncrewed Orion spacecraft around the moon and back. Along the way, Orion will also launch 10 shoebox-sized “cubesats” — miniature satellites — to study the Moon and the environment around it.

SLS BLOCK 1

ORION SPACECRAFT

322 feet

Upper

stage

(Orion)

Escape

tower

 

Protective

launch

cover

Crew

module

Core

stage

Solar

panels

(4)

Service

module

Spacecraft

adapter

Orion stage

adapter

“Cubesat”

miniature

satellites

(10)

Interim

cryogenic

propulsion

stage

Solid

rocket

boosters

(2)

RS25 rocket engines (repurposed space shuttle engines) (4)

RL10

rocket

engine

A long-awaited, and unusual, return to the moon

Orion will enter a long, looping orbit around the moon that will take it farther from the Earth than any crew-capable space vehicle has ever gone. There’s no crew, but sensor-packed mannequins will send back details on how the flight would go

if there were one.

Earth

The total mission is scheduled to take about 42 days.

“Distant

retrograde”

lunar orbit

Moon

Note: Orbit diagram is not to scale.

Source: NASA

WILLIAM NEFF/THE WASHINGTON POST

Artemis 1: New booster with a big mission

NASA’s new rocket will use “legacy” hardware — meaning, largely left over from the space shuttle program — to launch the uncrewed Orion spacecraft around the moon and back. Along the way, Orion will also launch 10 shoebox-sized “cubesats” — miniature satellites — to study the Moon and the environment around it.

SLS BLOCK 1 ROCKET

ORION SPACECRAFT

322 feet

Upper

stage

(Orion

spacecraft)

Escape

tower

 

Protective

launch

cover

Core

stage

(liquid

oxygen,

hydrogen

fuel)

Crew

module

Service

module

Solar

panels

(4)

Spacecraft

adapter

 

Orion stage

adapter

“Cubesat”

miniature

satellites

(10)

Interim

cryogenic

propulsion

stage

RS25 rocket engines (repurposed space shuttle engines) (4)

Solid

rocket

boosters

(2)

RL10

rocket

engine

A long-awaited, and unusual, return

to the moon

Orion will enter a long, looping orbit around the moon that will take it farther from the Earth than any crew-capable space vehicle has ever gone. There’s no crew, but sensor-packed mannequins will send back details on how the flight would go

if there were one.

“Distant retrograde”

lunar orbit

Earth

Moon

The total mission is scheduled

to take about 42 days.

Note: Orbit diagram is not to scale.

Source: NASA

WILLIAM NEFF/THE WASHINGTON POST

Artemis 1: New booster with a big mission

NASA’s new rocket will use “legacy” hardware — meaning, largely left over from the space shuttle program — to launch the uncrewed Orion spacecraft around the moon and back. Along the way, Orion will also launch 10 shoebox-sized “cubesats” — miniature satellites — to study the Moon and the environment around it.

SLS BLOCK 1 ROCKET

ORION SPACECRAFT

322 feet

Upper

stage

(Orion

spacecraft)

Escape

tower

 

Protective

launch

cover

Core

stage

(liquid

oxygen,

hydrogen

fuel)

Crew

module

Service

module

Solar

panels

(4)

Spacecraft

adapter

 

Orion stage

adapter

“Cubesat”

miniature

satellites

(10)

Interim

cryogenic

propulsion

stage

RS25 rocket engines (repurposed space shuttle engines) (4)

Solid

rocket

boosters

(2)

RL10

rocket

engine

A long-awaited, and unusual, return to the moon

Orion will enter a long, looping orbit around the moon that will take it farther from the Earth than any crew-capable space vehicle has ever gone. There’s no crew, but sensor-packed mannequins will send back details on how the flight would go if there were one.

“Distant retrograde”

lunar orbit

Earth

The total mission is scheduled

to take about 42 days.

Moon

Note: Orbit diagram is not to scale.

Source: NASA

WILLIAM NEFF/THE WASHINGTON POST

The SLS was born in 2010, after the Obama administration canceled the Constellation program, which would have built Orion and a pair of rockets — one to fly astronauts to the International Space Station, another to return to the moon. With the space shuttle set to be retired in 2011 after a second fatal accident back in 2003, Constellation was to be NASA’s next big human-spaceflight program. And since it maintained much of the workforce — particularly in Texas and Florida — that supported the space shuttle, it had key congressional support.

But after years of cost overruns and delays, the Obama White House determined that Constellation was on “an unsustainable trajectory” and “perpetuating the perilous practices of pursuing goals that do not match allocated resources.” So it moved to kill the program.

Congress, however, had other ideas.

It passed the NASA Authorization Act of 2010 that reinstated the Orion crew capsule and kept the heavy launch vehicle, renaming it the Space Launch System. The law directed NASA to build the rocket using space shuttle and Constellation contracts, so that even the engines used on the 1970s-designed space shuttle would power NASA’s new SLS.

“It is not too much of a simplification to say that the SLS is the modern implementation of the space shuttle workforce,” Dreier wrote.

For all its power, the SLS is also notable for what it does not do. As companies like SpaceX, Blue Origin and RocketLab are building rockets that are reusable, returning to Earth so they can be flown over and over, each SLS booster will fly only once, falling into the ocean after liftoff, never to be used again.

The RS-25 engines on the rocket were repurposed from the space shuttle. Combined, they flew in more than 20 shuttle missions, including one from 1998. They were designed to be reused again and again. But on the SLS they’ll be discarded for good.

Asked about the long-term viability of the SLS, Nelson said that SpaceX’s Starship and other heavy-lift rockets, such as Blue Origin’s New Glenn, are still in development and not yet ready to fly — though Starship appears to be getting close. “What we know is that SLS is the only human-rated rocket that can go into space now,” Nelson said. “And it will go farther, deeper into space than anywhere we have ventured with humans before.”

Despite working with legacy hardware, NASA and Boeing, the prime contractor on the rocket’s main stage, suffered through all sorts of setbacks and delays that have been chronicled in a series of critical reports issued by the Government Accountability Office and the NASA inspector general.

In 2019, a report by the GAO, for example, found that NASA continued to pay tens of millions of dollars in “award fees” to Boeing for scoring high on performance evaluations, even as the cost of the rocket was climbing and delays mounted. After issuing one award fee to Boeing, a NASA official even “noted that the significant schedule delays on this contract have caused NASA to restructure the flight manifest for SLS.”

Earlier this year, Paul Martin, NASA’s inspector general, told Congress that his office had calculated the cost for the first three flights of the SLS to be $4.1 billion each, a price tag he said was “unsustainable.” NASA and Boeing pushed back on that analysis, saying it included all sorts of unrelated costs, and Dreier calculated that the per-launch cost would be between $876 million to $2 billion, “depending on how one accounts for its related overhead costs.”

All of those estimates are huge numbers that come as the cost of launch is going down, not up, as SpaceX and other companies compete for launch contracts in a robust commercial marketplace. As Martin said, “relying on such an expensive, single-use rocket system will, in our judgment, inhibit if not derail NASA’s ability to sustain its long-term human exploration goals to the moon and Mars.”

All of which has led to a chorus of protest from the rocket’s critics, who deride it as the “Senate Launch System,” saying it does more to create jobs in key congressional districts than open new frontiers of exploration.

That’s in large part because construction of the rocket and the Orion spacecraft is spread out so that every state has jobs connected to the program. In all, the SLS supports about 25,000 jobs nationwide, with a total economic impact of $4.7 billion, according to NASA.

In addition to primary contractor Boeing, key contractors are some of the most powerful, and influential, in Washington: Aerojet Rocketdyne, Northrop Grumman and the United Launch Alliance, a joint venture of Lockheed Martin and Boeing.

In his analysis, Dreier noted that every single year since the program began in 2012, the SLS has received additional funding from Congress above what NASA had requested. In all, the SLS has received an additional $335 million, or 22 percent above NASA’s requests, on average per year.

“Despite cost overruns and ongoing delays, there has never been a serious political threat to the SLS from Congress or the White House,” Dreier noted. “This is independent of whether Democrats or Republicans are in control.”

It also has helped that the SLS program is stationed at the Marshall Space Flight Center in Huntsville, Ala., the home state of Shelby, the longtime chairman of the appropriations committee. The program has created about 13,000 jobs and pumped $2.4 billion into the state’s economy, and he has vigorously defended the program.

Especially in 2019, when Bridenstine floated the idea of sidelining the rocket. At the time, Shelby released a statement saying: “While I agree that the delay in the SLS launch schedule is unacceptable, I firmly believe that SLS should launch the Orion.”

Privately, his aides angrily chastised NASA officials.

The next day, Bridenstine reiterated his support for the SLS program in a blog post, saying the agency is “committed to building and flying SLS,” while NASA officials realized the technical challenges of switching rockets midstream.

Since then, however, Shelby announced he would retire at the end of this year, leaving the SLS without one of its most ardent supporters.

Under the Trump administration, the Artemis program was given high priority, especially by Vice President Mike Pence, a space enthusiast who pushed NASA to move with a sense of urgency. President Biden’s administration also has embraced Artemis, meaning the program is the first human deep-space effort to survive subsequent administrations since Apollo.

Despite the setbacks that plagued the SLS, the program finally gained momentum recently, competing a series of tests leading to launch including a successful “hot fire” test by firing its core stage engines for more than eight minutes last year.

But nothing has come easy. This spring, a few “wet dress rehearsal” tests to fully fuel the rocket and run a simulated countdown were cut short because of various problems including a faulty valve in the rocket’s second stage; problems with temperature readings of the propellant; and the malfunctioning of fans used to pressurize the mobile launch tower. NASA had to roll the rocket back to its assembly building at the Kennedy Space Center to make repairs before rolling it back out for another countdown attempt, which also was cut short, this time because of a hydrogen leak.

NASA officials said they got enough data to proceed with a launch attempt, and in recent days they have said the rocket is ready.

NASA officials recently held a “flight readiness review,” a days-long meeting where they discuss every aspect of the vehicle and the mission. It went well, officials said, with no major issues or dissent emerging.

“We did talk to the launch team,” said Jim Free, NASA’s associate administrator for the exploration systems development mission directorate. “We talked to the flight team. We talked to the recovery team, and then the management team and everybody said they’re ready to go.”

Still, officials said that the first flight of a rocket is fraught with challenges and unknowns and that things could go wrong. The flight will push the envelope since the Orion spacecraft was designed to fly humans for a total of 21 days. On this uncrewed flight, it is scheduled to fly for 42 days, which will stress some of its systems, NASA officials said.

“This is a test flight, all right. And it’s not without risk,” said Bob Cabana, NASA’s associate administrator. “We have analyzed the risk as best we can and we’ve mitigated also as best we can. But we are stressing Orion beyond what it was actually designed for, in preparation for sending it to the moon with a crew, and we want to make sure that it works absolutely perfectly when we do that.”

He said that some challenges that could emerge “that can cause us to come home early, and that's okay. We have contingencies in place.”

NASA rolled the rocket to the pad earlier this month preparing for launch. It can be seen for miles, a stunning sight on the Space Coast skyline that has generated renewed enthusiasm for America’s space program here. “We are going,” has become the NASA motto for the mission, a slogan ready made for social media and marketing banners.

A few hundred miles away, along the Gulf Coast in Texas, another rocket has been mounted on a launchpad: SpaceX’s Starship booster, which is preparing to go through a series of tests before its own launch attempt, which could come within the next year.

SpaceX, it turns out, is going, too.