— "Our shuttles need to refuel before they burn for the moon..."

That one line, from the penultimate episode of the now complete second season of "For All Mankind," seemed to answer one of, if not the most frequently asked questions about the Apple TV+ alternate space history series. The 11 words offer an explanation, however brief, for a point that was debated and discussed across multiple online communities, even though it was tangential to the series' plot lines.

How was it possible for NASA's space shuttles to fly to the moon?

"For All Mankind," which follows what might have happened if the Soviet Union beat the United States to landing the first astronaut, or rather cosmonaut, on the moon in the 1960s, jumped into the early 1980s for its second season, which as real history records is when the space shuttle-era began.

The actual winged orbiters never flew to the moon, although the public sometimes thought that they did. In response, NASA explained why not on its website.

"The space shuttle is designed to travel in low-Earth orbit (within a few hundred miles of the Earth's surface). It does not carry enough propellant to leave Earth's orbit and travel to the moon," the space agency stated.

And yet, multiple times in "For All Mankind," the series showed the shuttles flying to the moon.

As the series is set in a different timeline, one could write it off to being science fiction, were it not for the attention to detail that show creator Ronald D. Moore and his fellow producers and writers have paid to the actual history and to justifying the changes they have made. As a result, fans of "For All Mankind" took to Reddit and Facebook, to a wiki created specifically for the show and to YouTube to offer up their own explanations — some rather detailed, diving into the orbital mechanics of the problem.

A little fig leaf

"Okay, so we know it can't," Garrett Reisman, a former NASA astronaut who flew on the space shuttle, admitted in an interview with collectSPACE.

Reisman, who made a cameo appearance as the commander of the space shuttle Columbia on its way back from the moon, has served as a technical advisor for the series from its start.

"We all pointed out that the shuttle could never actually get to the moon. It had nowhere near enough delta-v," he said, referring to a change in velocity. "We even did calculations that showed if you filled up the payload bay with hydrazine and fed it to the [orbital maneuvering system] OMS engines, you still couldn't get to the moon and back without exceeding the payload mass of the orbiter."

"So we knew that," said Reisman.

But Reisman also knew that if they were going to overlook that, they had a good reason.

"The great thing about 'For All Mankind' is that they do try to get as much of the technical stuff as accurate as they can. But if there is something that feels really important to the story, the story is going to win," he said.

"When the story had to trump the physics, they always gave me the chance to at least put in a little 'fig leaf,' and if you listen really carefully, there's one line of dialogue in episode nine of season two where we do explain how the shuttle might have been able to get to the moon," Reisman said.

Facts versus finances

Moore could have avoided the whole question by not using the shuttle, or altering its design (as ultimately is done with the introduction of the second-generation Pathfinder orbiter), but he felt it was important to have the iconic vehicle included in the show's version of space exploration history.

"It's a touchstone for the audience in terms of the space program itself, especially in the 1980s," Moore told collectSPACE. "It would have felt odd to me, as a viewer, if there was no space shuttle because it was the forefront of the American space program for quite a while."

But there was also a practical reason to use the space shuttle.

"If we didn't use the shuttle and we had to create a whole new vehicle for travel, it was going to cost me a lot more," said Moore. "There would be no clips that I could use. There is an existing set that replicates the interior cockpit of the space shuttle. The spacesuits are available."

"So, in just a dollars and cents, producer part of me, it was like, if I give that up, I'm going to have to cut back on a lot of other things. Suddenly I won't have as much money to build a moon base. Suddenly I won't have as much money for a lot of other things. But if I can figure out a way to justify the use of the shuttle, it's going to help me a lot. It's not free, but it's a significant savings in terms of the production budget."

Moore found his justification in the shuttle's actual history.

"Thinking back to the evolution in the real history of the program, NASA comes to the Nixon administration and says 'What's after Apollo? Well, here's the big plan: the moon base, space stations, go to Mars, the space shuttle, and Nixon kind of goes, uh, how about just the shuttle?' And so it felt like in our version that existing plan was still kind of there when the Russians grab the moon at the last minute," said Moore.

In the "For All Mankind" timeline, NASA would develop the moon base and the space shuttle and then, instead of trying to invent a whole new vehicle, modified the orbiters so they could support the activities on the lunar surface.

"Wouldn't it make more sense financially and in terms of infrastructure and resources to find a way to use the existing platform and to refuel it, — maybe use some kind of fuel that is more efficient and an engine — yada yada yada, which is what we writers say when we deal with science to a certain extent. But there was at least a plausible idea that you could refuel the shuttle in orbit and send it to the moon," said Moore.

"That was the rationale that I talked Garrett into buying into," Moore said. "So if there is criticism, and I know there is certain criticism, people that don't quite believe it, that all belongs at my doorstep because ultimately I decided that it made sense for all the above reasons and it worked for the story."