yuri gagarin, the first human to orbit the earth. a little more physics. this demonstrates moment of inertia, which is kind of the resistance to rotation. you see a book -- you can do this at home yourself. it does not like to rotate about this axis. it tries to go back and rotate about the other two. see, this is the -- this is the smallest moment of intertia. and that is the intermediate one, the one it does not like. it wants to go about the largest or the smallest moment of inertia. all right. these next photos, i got from nasa. this is what the iss looked like in 2005. it is a lot different now. but this is the soyuz tma-7 i launched in. and that is going to stay there with a crew for six months. i came down in a different soyuz, tma-6. so the first thing i had to do when we docked was take my space suit and seat and move it to the soyuz here. that was going to be my means of egress in case of emergency. so, we slowly back away and we do about an orbit and a half. now remember, this is a vacuum. we are traveling over 17,000 miles an hour. but when we

. >> on april 12th, 1961, the russian cosmonaut yuri gagarin broke through earth's atmosphere. delivering a body blow to us dominance in science. >> "no nation which expects to be the leader of other nations can expect to stay behind in the race for space...we have vowed that we shall not see it governed by a hostile flag of conquest, but by a banner of freedom and peace...we choose to go to the moon!" >> think about how ridiculous that had to sound to the rest of the world because we hadn't yet put a single person into orbit. >> 500 years from now, in my opinion...there's only one thing that they remember about the 20th century that's a man went to the moon. >> "it's one small step for man - one giant leap for mankind." >> it really wasn't of significance who got to the moon first. >> so you don't see the landing on the moon as a great nationalistic achievement? >> there's no question this was a great propaganda achievement but if you actually think of the military significance it was not of any real consequence. >> we went to the moon for geopolitical purposes and absent the

yuri deguerin -- gagarin, the first human to orbit the earth. a little more physics.s demonstrates moment of inertia, which is kind of the resistance to rotation. you see a book -- you can do this at home yourself. it does not like to rotate at this axis. it tries to go back and rotate about the other two. this is the smallest moment of intertia. and that is the intermediate one, the one it does not like. it wants to go about the largest or the smallest moment of inertia. these next photos i got from nasa. this is what the iss looked like in 2005. it is a lot different now. but this is the sole use -- sl oyuz tma-7 i launched him. -- in. this will stay there with a crew for six months. i came down in a different soyuz, tma-6. the first thing i had to do when we docked was take my seat and move it to the soyuz here. that was going to be my means of egress in case of emergency. so, we slowly back away and we do about an orbit and a half. remember, this is a vacuum. we are traveling over 17,000 miles an hour. when we get down to that 100 or 60 mile layer we talked about