 Greetings and welcome to the Introduction to Astronomy. In this week's Exploration of the Solar System, we are going to look at the Apollo 7 through 10 missions. So these four missions were actually the first crewed launches after the Apollo 1 disaster. And again, we're setting the stage for the Apollo 11 mission coming up that would first actually land humans on the moon. So let's take a look at these. First of all, these were the first now crewed missions that actually launched into space. So the first crewed missions of the Apollo program. Apollo 7 launched on October 11th of 1968 was a test of the command module in space. So this was in Earth orbit and consisted of the first live broadcast of an American crew from space as we see an image here of the crew up in the command module broadcasting down to Earth. Now Apollo 8 launched a couple of months later in December of 1968 was actually the first crewed craft to leave the Earth and travel to the moon and gave us some famous images such as the one scene here where we could see the Earth rising over the lunar limb as the command module traveled around the moon and then as it came around we would watch the Earth rising up over the limb of the moon. Now we can see the Earth there as a phase, a little over a quarter phase, so a little more than half of the Earth seen as illuminated. So just as we see phases of the moon from Earth, the moon will go through, the Earth will go through phases as seen from the moon. But this was the first time that humans had traveled to the moon not landing on it just making kind of a loop around it. And then we had a little bit closer to home Apollo 9 in March of 1969 was a test of the lunar module not at the moon but in Earth orbit here. So we had again a crew testing out the lunar module and getting prepared we're getting really close now to the first human landing on the moon. So we tested out the lunar module in Earth orbit as we see the Earth with the cloud cover down below and the last of the missions we want to look at is the Apollo 10 mission from May 18th of 1969 just two months before the Apollo 11 mission. And this was a test of the lunar module at the moon. So again traveled out to the moon went into lunar orbit and were able to test them test the lunar module in lunar orbit and in fact came very close to landing and the craft was flown down to within about 10 miles or so of the lunar surface as a test to see how everything worked. Again it was never planned to be a landing it was getting down there and testing out all of the systems in preparation for the next mission which would be the first actual landing on the moon. So the craft had to separate from the command module which would have still been in lunar orbit descend down to within several miles of the lunar surface and then use its rockets to propel it back up and then redock with the command module so again multiple tests that were done in preparation for the Apollo 11 mission. So let's go ahead and look at what we can summarize here and what we've looked at with Apollo 7 through 10 there again were designed to test components in preparation for the first human landing on our moon. They tested both the command module and the lunar module in earth orbit and around the moon as well and these paved the way for the Apollo 11 moon landing in July of 1969. So that concludes this lecture on the Apollo 7 through 10 missions. We'll be back again next week for another exploration of the solar system. So until then, have a great day everyone and I will see you in class.