 For those of you living in the United States or traveling to the U.S. to see it, the total solar eclipse on August 21st is going to be a once-in-a-lifetime event not to be missed, and I'm super excited to be hosting a live broadcast for Time magazine. But of course, there are other eclipses that are worth talking about. Namely the first time humans saw an eclipse from space. It was Jim Lovell and Buzz Aldrin on Gemini 12. Gemini 12 was the 10th and final manned mission of the Gemini program, the interim program between Mercury and Apollo that really taught NASA how to fly in space. And as the final mission, it was going to be the sum of the program's full parts. This mission was going to go through everything that NASA had done with Gemini missions. The crew of Jim Lovell as the commander and Buzz Aldrin as the pilot had a hefty workload ahead of them for their mission. The mission would see the crew do multiple rendezvous and docking tests with the Agena target vehicle, three EVAs, propulsion system tests using the Agena's main engine to change orbit, demonstrate automatic reentry, as well as run 14 scientific, medical and technological experiments on board. The crew was also scheduled to photograph a solar eclipse happening on November 12th, but that goal fell by the wayside when the launch was delayed from November 9th to November 11th. Because the launch was delayed, the entire flight plan shifted. Under the new flight plan, the crew would be in the middle of their high altitude experiments using the Agena's main engine right at the time of the solar eclipse. They wouldn't have time for the photography experiment, and really it was a secondary goal to testing the high altitude flight using the Agena. The tests with the Agena were of course supporting eventual Apollo missions to the moon. But as will happen with spaceflight, things did not exactly go according to plan. The Agena target vehicle didn't launch with the Gemini spacecraft, it launched separately ahead of time, and this Agena's launch wasn't perfect. Eight minutes after the launch, the main engine suffered a momentary 6% decay and thrust chamber pressure, and this brought a corresponding drop in turbine speed. So while Lovell and Aldrum were safe to dock and redock with the Agena, flight controllers in Houston decided it wasn't the best idea to try to fire that main engine just to raise Gemini-12's orbit. Losing the high orbital portion of Gemini-12's flight left the crew with some downtime, and that downtime happened to correspond with the timing of the solar eclipse. And the Agena had a secondary propulsion system on board, one that flight controllers realized they could use to put Gemini-12 in the right orbit to actually photograph the eclipse after all. So they were back to this old flight plan goal. The addition of this goal was a little bit awkward. It came at a time when the crew was working with the Agena and also had things like eating and sleeping and other experiments in their schedule. But eclipses don't exactly wait. Seven hours and five minutes after launch, Jim Lovell fired the Agena's smaller engines to slow Gemini-12's speed, and some people were still a little bit nervous. Capcom Pete Conrad told them, if it gets away from you, meaning the Agena, take it over with the spacecraft. But the Agena's secondary propulsion system worked beautifully, and the crew was able to go to bed with their orbit slightly adjusted. After a sleep period, the crew performed a second phasing maneuver also using the Agena's secondary propulsion system. This one came 15 hours and 16 minutes after launch to put Gemini-12 into an orbit that was 160.3 by 136.6 nautical miles. They were at an inclination of 28.88 degrees and had an orbital period of just over 90 minutes. It basically put them in the perfect phase with the solar eclipse on their 10th revolution. The burns worked beautifully. At 16 hours and one minute after launch, the crew saw the eclipse, as they called it, right on the money. And they were able to take these beautiful photographs of the event, the first time humans had ever seen a solar eclipse from space. Of course, this wasn't the last time astronauts would see an eclipse from space. The crew of Apollo 12 saw one while returning from the moon in 1969, and a host of astronauts have photographed them from the International Space Station. So what are you guys doing for the upcoming total solar eclipse? And do you have other eclipse-based questions? Obviously, leave those in the comments down below. If you're not doing anything for this eclipse coming up, why not watch the live broadcast from time that I will be hosting? All the links and information that you need is in the description below, so definitely check that out, mark your calendars, and be sure to subscribe to time so that you get a notification when that broadcast goes live. And if you also want updates about that live stream event from me directly, be sure to follow me on Twitter and on Instagram because I will be posting about it. And if you want weekly vintage-based videos, be sure to give this one a like and subscribe so you never miss an episode.