WEBVTT 99:59:59.999 --> 99:59:59.999 So many of you have probably seen the movie "The Martian." 99:59:59.999 --> 99:59:59.999 But for those of you who did not, it's a movie about an astronaut 99:59:59.999 --> 99:59:59.999 who is stranded on Mars and his efforts to stay alive 99:59:59.999 --> 99:59:59.999 until the Earth can send a rescue mission to bring him back to Earth. 99:59:59.999 --> 99:59:59.999 Gladly, they do re-establish communication with the character, astronaut Watney, 99:59:59.999 --> 99:59:59.999 at some point, so that he's not as alone on Mars until he can be rescued. 99:59:59.999 --> 99:59:59.999 So while you're watching the movie, and even if you haven't, 99:59:59.999 --> 99:59:59.999 when you think about Mars, you're probably thinking about 99:59:59.999 --> 99:59:59.999 how far away it is and how distant. 99:59:59.999 --> 99:59:59.999 And, what might not have occurred to you is, 99:59:59.999 --> 99:59:59.999 what are the logistics really like of working on another planet? 99:59:59.999 --> 99:59:59.999 Of living on two planets when 99:59:59.999 --> 99:59:59.999 there are people on the Earth and there are rovers or people on Mars? 99:59:59.999 --> 99:59:59.999 So think about when you have friends, families and co-workers in California, 99:59:59.999 --> 99:59:59.999 on the West Coast or in other parts of the world. 99:59:59.999 --> 99:59:59.999 When you're trying to communicate with them, one of the things 99:59:59.999 --> 99:59:59.999 you probably first think about is -- 99:59:59.999 --> 99:59:59.999 Wait, what time is it in California? 99:59:59.999 --> 99:59:59.999 Will I wake them up? Is it okay to call? 99:59:59.999 --> 99:59:59.999 So even if you're interacting with colleagues who are in Europe, 99:59:59.999 --> 99:59:59.999 you're immediately thinking about, 99:59:59.999 --> 99:59:59.999 what does it take to coordinate communication when people are far away? 99:59:59.999 --> 99:59:59.999 So we don't have people on Mars right now, but we do have rovers. 99:59:59.999 --> 99:59:59.999 And actually right now, on Curiosity, it is 6:10 in the morning on Mars. 99:59:59.999 --> 99:59:59.999 We have four rovers on Mars. The United States has put four rovers 99:59:59.999 --> 99:59:59.999 on Mars since the mid-1990s, 99:59:59.999 --> 99:59:59.999 and I have been privileged enough to work on three of them. 99:59:59.999 --> 99:59:59.999 So, I am a spacecraft engineer, a spacecraft operations engineer, 99:59:59.999 --> 99:59:59.999 at NASA's Jet Propulsion Laboratory in Los Angeles, California. 99:59:59.999 --> 99:59:59.999 And these rovers are robotic emissaries. 99:59:59.999 --> 99:59:59.999 So, they are our eyes and our ears and they see the planet for us 99:59:59.999 --> 99:59:59.999 until we can send people. 99:59:59.999 --> 99:59:59.999 So we learn how to operate on other planets through these rovers. 99:59:59.999 --> 99:59:59.999 So before we send people, we send robots. 99:59:59.999 --> 99:59:59.999 So the reason there's a time difference on Mars right now, 99:59:59.999 --> 99:59:59.999 from the time that we're at 99:59:59.999 --> 99:59:59.999 is because the Martian day is longer than the Earth day. 99:59:59.999 --> 99:59:59.999 Our Earth day is 24 hours because that's 99:59:59.999 --> 99:59:59.999 how long it takes the Earth to rotate, how long it takes to go around once. 99:59:59.999 --> 99:59:59.999 So our day is 24 hours. 99:59:59.999 --> 99:59:59.999 It takes Mars 24 hours and approximately 40 minutes to rotate once. 99:59:59.999 --> 99:59:59.999 So that means that the Martian day is 40 minutes longer than the Earth day. 99:59:59.999 --> 99:59:59.999 So teams of people who are operating the rovers on Mars, like this one, 99:59:59.999 --> 99:59:59.999 what we are doing is we are living on Earth, but working on Mars. 99:59:59.999 --> 99:59:59.999 So we have to think as if we are actually on Mars with the Rover. 99:59:59.999 --> 99:59:59.999 Our job, the job of this team, of which I'm a part of 99:59:59.999 --> 99:59:59.999 is to send commands to the rover to tell it what to do the next day. 99:59:59.999 --> 99:59:59.999 To tell it to drive or drill or tell her whatever she's supposed to do. 99:59:59.999 --> 99:59:59.999 So while she's sleeping -- and the rover does sleep at night 99:59:59.999 --> 99:59:59.999 because she needs to re-charge her batteries 99:59:59.999 --> 99:59:59.999 and she needs to weather the cold Martian night. 99:59:59.999 --> 99:59:59.999 And so she sleeps. 99:59:59.999 --> 99:59:59.999 So while she sleeps, we work on her program for the next day. 99:59:59.999 --> 99:59:59.999 So I work the Martian night shift. 99:59:59.999 --> 99:59:59.999 So in order to come to work on the Earth at the same time every day on Mars -- 99:59:59.999 --> 99:59:59.999 like, let's say I need to be at work at 5:00 pm, 99:59:59.999 --> 99:59:59.999 this team needs to be at work at 5:00 pm Mars time every day, 99:59:59.999 --> 99:59:59.999 then we have to come to work on the Earth 40 minutes later every day, 99:59:59.999 --> 99:59:59.999 in order to stay in sync with Mars. 99:59:59.999 --> 99:59:59.999 That's like moving a time zone every day. 99:59:59.999 --> 99:59:59.999 So one day you come in at 8:00, the next day 40 minutes later at 8:40, 99:59:59.999 --> 99:59:59.999 the next day 40 minutes later at 9:20, the next day at 10:00, 99:59:59.999 --> 99:59:59.999 so you keep moving 40 minutes every day, 99:59:59.999 --> 99:59:59.999 until soon you're coming to work in the middle of the night -- 99:59:59.999 --> 99:59:59.999 the middle of the Earth night. 99:59:59.999 --> 99:59:59.999 Right? So you can imagine how confusing that is. 99:59:59.999 --> 99:59:59.999 Hence, the Mars watch. 99:59:59.999 --> 99:59:59.999 This watch has been mechanically -- 99:59:59.999 --> 99:59:59.999 the weights have been mechanically adjusted so that it runs more slowly. 99:59:59.999 --> 99:59:59.999 When I got this watch in 2004 99:59:59.999 --> 99:59:59.999 with Spirit and Opportunity, the rovers back then, 99:59:59.999 --> 99:59:59.999 we didn't start out thinking that we were going to need Mars watches. 99:59:59.999 --> 99:59:59.999 Right? We thought, okay, we'll just have the time on our computers 99:59:59.999 --> 99:59:59.999 and on the mission control screens and that would be enough. 99:59:59.999 --> 99:59:59.999 Yeah, not so much. 99:59:59.999 --> 99:59:59.999 Because we weren't just working on Mars time, 99:59:59.999 --> 99:59:59.999 we were actually living on Mars time. 99:59:59.999 --> 99:59:59.999 And we got just instantaneously confused about what time it was. 99:59:59.999 --> 99:59:59.999 So you really needed something on your wrist to tell you, alright, 99:59:59.999 --> 99:59:59.999 what time is it on the Earth, what time is it on Mars. 99:59:59.999 --> 99:59:59.999 And it wasn't just the time on Mars that was confusing, 99:59:59.999 --> 99:59:59.999 we also needed to be able to talk to each other about it. 99:59:59.999 --> 99:59:59.999 So a "sol" is a Martian day -- again, 24 hours and 40 minutes. 99:59:59.999 --> 99:59:59.999 So when we're talking about something that's happening on the earth, 99:59:59.999 --> 99:59:59.999 we will say, today. 99:59:59.999 --> 99:59:59.999 So, for Mars, we say, "tosol." 99:59:59.999 --> 99:59:59.999 Yesterday became 'yestersol' for Mars. 99:59:59.999 --> 99:59:59.999 Again, we didn't start out thinking, "oh let's invent a language." 99:59:59.999 --> 99:59:59.999 It was just very confusing. 99:59:59.999 --> 99:59:59.999 I remember someone walked up to me and said, 99:59:59.999 --> 99:59:59.999 "I would like to do this activity on the vehicle tomorrow, on the rover." 99:59:59.999 --> 99:59:59.999 And I said, "tomorrow, tomorrow, or Mars tomorrow?" Right? 99:59:59.999 --> 99:59:59.999 We started this terminology because we needed a way to talk to each other. 99:59:59.999 --> 99:59:59.999 Tomorrow became "nextersol" or "solorrow" 99:59:59.999 --> 99:59:59.999 because people had different preferences for the words they use. 99:59:59.999 --> 99:59:59.999 Some of you might say soda and some of you might say pop. 99:59:59.999 --> 99:59:59.999 So we have people who say nextersol or solorrow. 99:59:59.999 --> 99:59:59.999 And then something that I noticed after a few years of working on these missions, 99:59:59.999 --> 99:59:59.999 was that the people who work on the rovers, we say "tosol." 99:59:59.999 --> 99:59:59.999 The people who work on the landing missions that don't rove around, 99:59:59.999 --> 99:59:59.999 they say "tosol." [Different vowel sound] 99:59:59.999 --> 99:59:59.999 So I could actually tell what mission you worked on from your Martian accent. 99:59:59.999 --> 99:59:59.999 [Laughter] 99:59:59.999 --> 99:59:59.999 So we have the watches and the language and you're detecting a theme here, right?. 99:59:59.999 --> 99:59:59.999 So that we don't get confused. 99:59:59.999 --> 99:59:59.999 But even the Earth daylight could confuse us. 99:59:59.999 --> 99:59:59.999 If you think that right now, you've come to work 99:59:59.999 --> 99:59:59.999 and it's the middle of the Martian night and there's light streaming in 99:59:59.999 --> 99:59:59.999 from the windows, that's confusing as well. 99:59:59.999 --> 99:59:59.999 So you can see from this image of the control room 99:59:59.999 --> 99:59:59.999 that all of the blinds are down. 99:59:59.999 --> 99:59:59.999 So that there's no light to distract us. 99:59:59.999 --> 99:59:59.999 The blinds went down all over the building about a week before landing 99:59:59.999 --> 99:59:59.999 and they didn't go up until we went off Mars time. 99:59:59.999 --> 99:59:59.999 So this also works for the house, for at home. 99:59:59.999 --> 99:59:59.999 So I've been on Mars time three times, and my husband is like, okay, 99:59:59.999 --> 99:59:59.999 we're getting ready for Mars time. 99:59:59.999 --> 99:59:59.999 And so he'll put foil all over the windows and dark curtains and shades 99:59:59.999 --> 99:59:59.999 because it also affects your families. 99:59:59.999 --> 99:59:59.999 And so here I was living in kind of his darkened environment but so was he, 99:59:59.999 --> 99:59:59.999 and he'd gotten used to it, 99:59:59.999 --> 99:59:59.999 but then I would get these plaintive emails from him when he was at work. 99:59:59.999 --> 99:59:59.999 Should I come home? Are you awake? What time is it on Mars? 99:59:59.999 --> 99:59:59.999 And I decided, okay, so he needs a Mars watch. 99:59:59.999 --> 99:59:59.999 [Laughter] 99:59:59.999 --> 99:59:59.999 But of course, it's 2016, so there's an app for that. 99:59:59.999 --> 99:59:59.999 So now instead of the watches, we can also use our phones. 99:59:59.999 --> 99:59:59.999 But the impact on families was just across the board, 99:59:59.999 --> 99:59:59.999 it wasn't just those of us who were working on the rovers 99:59:59.999 --> 99:59:59.999 but our families as well. 99:59:59.999 --> 99:59:59.999 This is David O, one of our flight directors, 99:59:59.999 --> 99:59:59.999 and he's at the beach in Los Angeles with his family at 1:00 in the morning. 99:59:59.999 --> 99:59:59.999 So because we landed in August 99:59:59.999 --> 99:59:59.999 and his kids didn't have to go back to school until September, 99:59:59.999 --> 99:59:59.999 they actually went on to Mars time with him for one month. 99:59:59.999 --> 99:59:59.999 They got up 40 minutes later every day 99:59:59.999 --> 99:59:59.999 and they were on dad's work schedule. 99:59:59.999 --> 99:59:59.999 So they lived on Mars time for a month and had these great adventures, 99:59:59.999 --> 99:59:59.999 like going bowling in the middle of the night 99:59:59.999 --> 99:59:59.999 or going to the beach. 99:59:59.999 --> 99:59:59.999 And one of the things that we all discovered 99:59:59.999 --> 99:59:59.999 is that you can get anywhere in Los Angeles 99:59:59.999 --> 99:59:59.999 at 3:00 in the morning when there's no traffic. 99:59:59.999 --> 99:59:59.999 So we would get off work and -- 99:59:59.999 --> 99:59:59.999 you know we didn't want to go home and bother our families -- 99:59:59.999 --> 99:59:59.999 and we were hungry, 99:59:59.999 --> 99:59:59.999 so instead of going locally to eat something, we'd go, 99:59:59.999 --> 99:59:59.999 "wait, there's this great all-night deli in Long Beach, 99:59:59.999 --> 99:59:59.999 and we can get there in 10 minutes." 99:59:59.999 --> 99:59:59.999 It was like the 60s, no traffic. 99:59:59.999 --> 99:59:59.999 So we would drive down there, and the restaurant owners would go,. 99:59:59.999 --> 99:59:59.999 "who are you people ,and why are you at my restaurant at 3:00 in the morning?" 99:59:59.999 --> 99:59:59.999 So they came to realize that there were these packs of Martians, 99:59:59.999 --> 99:59:59.999 roaming the LA freeways, in the middle of the night, 99:59:59.999 --> 99:59:59.999 in the middle of the Earth night. 99:59:59.999 --> 99:59:59.999 And we did actually start calling ourselves Martians. So those of us who were on Mars time would refer to ourselves as Martians and everyone else as Earthlings. And that's because when you're moving a time-zone every day, you start to really feel separated from everyone else. You're literally in your own world. So I have this button on that says, "I survived Mars time. Sol 0-90" and there's a picture of it up on the screen. So the reason we got these buttons is because we work on Mars time in order to be as efficient as possible with the rover on Mars, to make the best use of our time. But we don't stay on Mars time for more than three to four months. Eventually, we'll move to a modified Mars time, which is what we're working now. And that's because it's hard on your bodies, it's hard on your families -- in fact, there were sleep researchers who actually were studying us because it was so unusual for humans to try to extend their