For the first episode in “The Greatest Leap,” we focused on the Apollo 1 fire and NASA’s return to flight after that tragic accident. Without that turnaround, the United States might never have landed on the Moon during the 1960s, or at all. Now, we offer a teaser for the second part of the series, which will publish on Tuesday, December 12.

After the successful Apollo 7 mission, NASA had a choice. It could play it safe, or the agency could push its chips into the middle of the table and go all-in on the Moon. This led to perhaps the gutsiest call in spaceflight history: a mission profile that took humans beyond low-Earth orbit and deep into the gravity well of another world—the Moon. Our video and story includes interviews with the flight controllers and engineers who helped make these critical decisions and delivered a key victory in the Space Race.

This is the second of what will eventually be a seven-segment series. We are rolling out the first three parts back-to-back across three weeks in December. After a break, the last three will run back-to-back across three weeks in February (and we’ll have an Apollo spaceship explainer running in the middle). We’ll also continue to share our complete video interviews with the Apollo-era figures who helped lead the charge to the Moon. We’ve already published interviews with flight director Chris Kraft and Apollo 7 astronaut Walt Cunningham. More are on the way.