SLS Green Run Test
Enlarge / And the day that was comes to a close at NASA’s Stennis Space Center after the SLS rocket fired up for the Green Run test on January 16, 2021.

Trevor Mahlmann

Nearly two years ago, then Vice President Mike Pence delivered the most consequential space policy speech of his tenure in office. During a National Space Council meeting at Marshall Space Flight Center in Alabama, Pence laid out the Trump administration’s plans to land humans on the Moon by the year 2024.

“We must redouble our efforts here in Huntsville and throughout this program,” said Pence, speaking to engineers leading development of NASA’s Space Launch System rocket. “We must accelerate the SLS program to meet this objective. But know this: The President has directed NASA and Administrator Jim Bridenstine to accomplish this goal by any means necessary.”

At the time, NASA engineers at Marshall told Pence they were confident the SLS rocket would make its debut flight in 2020, setting up a schedule to allow astronauts to return to the Moon by 2024. Even so, Pence maintained he was not committed to any single rocket, or contractor. The Moon was the goal—not the means of reaching it.

“If our current contractors can’t meet this objective, then we’ll find ones that will,” Pence said in Huntsville. “If American industry can provide critical commercial services without government development, then we’ll buy them. And if commercial rockets are the only way to get American astronauts to the Moon in the next five years, then commercial rockets it will be.”

Two years have since come and gone. The vice president’s ambitious 2024 goal of landing on the Moon has fallen out of reach. Pence has left office. And of course, the SLS rocket did not launch in 2020. Now, it’s virtually certain to not launch before 2022. So what comes next?

Any means necessary

What to do with the Space Launch System rocket is one of the biggest space policy questions the Biden Administration—which has yet to name its principal leaders—must face in the coming months. It’s true that the large rocket NASA has spent a decade, and nearly $20 billion developing, is getting closer to launching. However, there are no guarantees about when the SLS will be ready.

From Pence’s speech, it is clear he spent time learning about NASA’s issues, was frustrated, and sought to address them. This rocket was originally due to launch in 2016, and he was fed up with delays. The nation, Pence felt, could do better. As one senior astronaut, who was not a fan of the Trump administration, told Ars, “He’s the first vice president who has given a sh– about space in 20 years.”

However, the reality is that without extraordinary effort, the White House cannot corral a program like the SLS rocket, which enjoys broad support in Congress and supports jobs across the country. And the Trump administration never did.

When push came to shove, the White House went along with NASA, Congress, and the big contractors like Boeing that are building the SLS rocket, spending about $2.5 billion every year to keep it going. And while the SLS didn’t launch in 2020, it did reach a test stand in Mississippi, in preparation for a big static fire test earlier this month. The goal was to ignite the rocket’s four main engines for four to eight minutes, showing its readiness for launch. Unfortunately, the rocket’s core stage only fired for 67.2 seconds, and now NASA is considering whether it needs to test fire the rocket again before shipping it to its launch pad at Kennedy Space Center in Florida.

Following the test on January 16, and after a news conference to discuss its preliminary results, Ars spoke with NASA Administrator Jim Bridenstine. He acknowledged things had not gone as planned, but said the SLS program was moving forward. “We’re close,” he said. “We are so close.”

When Pence laid out the Moon plan in 2019, it had fallen to Bridenstine to cobble together the plan to get humans to the lunar surface in five years. Within days of Pence’s speech, Bridenstine seemed to be doing just that. He appeared before Congress and said NASA was studying the possibility of using SpaceX’s Falcon Heavy rocket—already flying—to get the job done. But very soon, influential members of Congress told him to knock it off. Despite Pence’s talk of finding other contractors, the House and Senate were having none of it. For almost the entirety of the rest of his tenure, Bridenstine spoke only of SLS launching humans to the Moon. The “commercial rocket” insurrection was over.

Only after the big core stage test this January, and with less than four days remaining in his tenure as NASA Administrator, did Bridenstine waver slightly on this position. “NASA needs to go back and look at what the options are to go to the Moon as quickly as possible,” he said. “And I think that the SLS rocket is going to be that option, if we’re talking about sending humans to the Moon.”

Opportunity costs

The SLS rocket may be close, but the opportunity costs of flying it are high for NASA. Although the agency does need a large, powerful rocket to send humans and lots of cargo into deep space, it perhaps does not need one based on technologies from the space shuttle era, now nearly 50 years old, as the SLS booster is.

In going this way, NASA is missing out on the revolution in launch spearheaded by SpaceX, but soon to be followed by Blue Origin in the United States, and other space agencies around the world. As China, Europe, Japan, and others look to their next generation of rockets, they are all factoring in reuse and the potential for many launches instead of a few.

When he talked about why his Blue Origin rocket company had been designed for reuse from the beginning, Jeff Bezos made this comment in 2016. “Right now, the things you do in space have to be incredibly important, and because space access is so expensive, if you can do it another way, you will,” Bezos said. “That’s why you get very few launches. That changes if you can dramatically lower the cost of access, and the only way to do that is reusability.”

By spending the entire last decade developing a large, expensive rocket that can be used a single time, NASA has largely ignored technologies that might enable a more sustainable space transportation system. Until recently, the space agency had not been investing in reusable space tugs to move cargo between the Earth and the Moon, harvesting water resources from the Moon and asteroids, and storing and transferring propellant in space. These technologies—in concert with low-cost launch—are likely to be the breakthroughs that facilitate space travel in the 21st century. Instead, Congress has told NASA to look backward rather than forward.

After this month’s aborted static fire test, the future of the SLS rocket is uncertain. No one is sure how the Biden administration will proceed, or what Congress’ reaction might be. However, we can make some assumptions.

If the SLS rocket fails catastrophically during the test phase, which is unlikely, or does not succeed on its first test launch in a year or so, the program will become much more vulnerable to cancellation. This may seem unfair, but given the linear nature of the design and development program for the SLS rocket, it is not really undergoing a “test” campaign, but rather a “validation” campaign.

The second thing that would probably accelerate the end of the SLS rocket would be the successful launch of SpaceX’s Starship vehicle on a Super Heavy rocket. This launch system has a greater lift capacity than SLS, is fully reusable, and likely could be operated at a tenth of the cost—or much less. This may happen before the end of 2021, but the ambitious Starship program still must address significant technical challenges.

The fact that the 2024 Moon landing goal is no longer attainable may loom large in the Biden administration’s calculus regarding SLS. If the big rocket is no longer needed soon for a 2024 landing, then what is the harm in waiting for less expensive commercial rockets to come along? More likely, however, the Biden administration will continue to fund the SLS rocket, but may attempt to slow or stop funding for an enhancement—the Exploration Upper Stage under development by Boeing—that will cost billions of dollars more.

We should get some answers on these questions in the coming months.