rocket booster segments was a result of the joint leakage, determined to be the cause of the accident. presidential conclusion admitted that it was the failure of the pressure seal on the right socket motor. the failure was due to a faulty design, rendering it unacceptably vulnerable to a number of factors, including the effective temperature, physical dimensions, the character of materials, the effective reuse and processing and joint dynamic loading. more detailed analysis are contained in volume three in the report on the presidential commission of the space shuttle challenger accident.

>> 30 years ago, january 28, 1986, the space shuttle challenger exploded 73 seconds after liftoff, taking the lives of the seven crew members pictured here on their way to schoolnchpad, including teacher who was selected from over 11,000 applicants to be the teacher infirst space. next, a 10 minute nasa video of , on the right in this video, with backup teacher barbara morgan. they are shown being fitted for space clothing. [laughter]

[laughter] [indiscernible] >> that's all right, you missed the world's greatest teacher. ok, this is one with time to get one. >> we haven't really done it. me what time they were stepping one foot. we said it would be less than eight hours. we talked briefly with them this morning.

[inaudible] [laughter] >> guess i will take one of everything. >> is this enough like a normal day? >> no. [laughter] i still keep looking around for my students. this, when you drink it, keeps the liquid from coming out. >> like that. >> ok. >> and then you just close it? >> if you are sitting in zero

gravity, it may have propensity to come around. you can take it out. you don't have to before you take it out of your mouth. you don't want to leave it sitting around. that's each one. >> ok. >> we have a snowball. [laughter] >> ok, why don't we do it this way?

[indiscernible] >> just wrap it around your leg there. ok, have a seat. all right? ok. this doesn't have to be real tight on you. just going to take the slack out of these here. you andcklist will tell

i will have you work with this hardware. back on the, pull nozzle. pull back on that. slowly it will build up to a half. [laughter] [indiscernible] if you move your legs around, you will hear it creaking and groaning. all right, let's say that the orbiter lands and you are feeling lightheaded.

this little line right here, all you have to do is pull out the hidden. that traps the air. you can then go ahead and disconnected this point. >> like you said. >> ok? get your chin right up in there, that's right. get your fingers down a little bit lower. come right there, bring that forward. that will be used strictly in an emergency.

go ahead and flip that over. >> how can you hear me? >> fine. >> tighten the bracket in the back. he got your hand on it right now. there you go. is that getting more snug on your face there? ok. go ahead with your right hand and close the visor. you just have to push and pull down like this.

there you go. ahead and talk. ok? >> oh, no. [laughter] >> i can't wear anything. >> trousers and assured with a nasa patch on it. most people like it that way, comfortable. >> coveralls. you can try them there. >> those are not pockets.

they said that when you get on orbit you will have a chance for your leg with your torso area. >> ok. >> ok. >> i see. >> it's a much bigger way. >> icy. >> one of those chairs? >> is the length ok? >> go there first. >> it's all right. >> sometimes you will be standing in it. >> you are basically the same.

what were you going to say? >> just that this must feel a little bit chilly. >> ok, so you want to carry this. >> my gosh. >> would you mind getting handkerchiefs from the locker room? >> that's not us. >> you wear these for the launch. once you're up there, you don't need them anymore. [indiscernible] you could pull it in on there, too. there you go.

[captioning performed by the national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org] [captions copyright national cable satellite corp. 2016] "q&a," scott christiansen gives us his thoughts on the most influential documents in the world. >> there is a lot of criticism of snowden. but there is also a very strong feeling that he's an american hero and is viewed as such around the world. so, it does really cause people to question, you know, who controls documents, who owns documents, what is the power of documents, what are these things about that the government is collecting? "q&a." >> each week "road to the white house

rewind" brings you archival coverage of the presidential races. up next, look at the 2004 campaign and concession speech from howard dean. a month earlier the former vermont governor was widely considered the front runner the nomination, but his lead dwindled as the caucuses approached and he finished third behind john kerry and john edwards. he eventually dropped out of the race while senator kerry went on to win the party's nomination. deanarkin introduces mr. at this 15 minute event. you ready?kin: are are you ready to take on this fight? are you ready not to give up? are you ready to change america? then you are r f