1 00:00:00,000 --> 00:00:04,000 Technology really is the key to astronaut training and the tools they use. 2 00:00:04,000 --> 00:00:09,000 Right, but what about the research being conducted aboard the International Space Station? 3 00:00:09,000 --> 00:00:11,000 Yeah, and the microgravity environment. 4 00:00:11,000 --> 00:00:15,000 How does that affect the astronauts working and living in space? 5 00:00:15,000 --> 00:00:20,000 Well, for answers we came here, to Building 9 at the Johnson Space Center. 6 00:00:22,000 --> 00:00:27,000 What's unique about the research environment on the International Space Station? 7 00:00:27,000 --> 00:00:31,000 How does zero gravity affect fluids in your body? 8 00:00:31,000 --> 00:00:35,000 Describe the relationship between time in space and bone loss. 9 00:00:37,000 --> 00:00:41,000 As the research manager for the ISS program here at the Johnson Space Center, 10 00:00:41,000 --> 00:00:46,000 it's my job to communicate with scientists who want to do research onboard the space station. 11 00:00:46,000 --> 00:00:52,000 I also work with the builders of the station to be sure it's both a well-equipped laboratory and observatory. 12 00:00:52,000 --> 00:00:56,000 You see, the ISS is about exploration, human exploration. 13 00:00:56,000 --> 00:00:59,000 It's the place where we will learn to live and work in space. 14 00:00:59,000 --> 00:01:03,000 It's where we'll establish a permanent human presence in space 15 00:01:03,000 --> 00:01:06,000 and advance human exploration of our solar system. 16 00:01:06,000 --> 00:01:09,000 What kind of work will be conducted on the ISS? 17 00:01:09,000 --> 00:01:13,000 Research. We will work on improving manufacturing processes, 18 00:01:13,000 --> 00:01:19,000 developing better health care, and researching tomorrow's products today. 19 00:01:19,000 --> 00:01:22,000 All this research will take place in the laboratories you saw earlier 20 00:01:22,000 --> 00:01:25,000 and in the unique, out-of-this-world environment of space. 21 00:01:25,000 --> 00:01:31,000 You see, the microgravity environment and the high vantage point for viewing Earth and the universe are unique. 22 00:01:31,000 --> 00:01:37,000 The permanent space station allows experiments to run for longer times than we used to on the space shuttle 23 00:01:37,000 --> 00:01:40,000 and gives scientists repeated access to these experiments. 24 00:01:40,000 --> 00:01:43,000 This research cannot be done on Earth. 25 00:01:43,000 --> 00:01:47,000 Well, Dr. Bartow, it sounds like a microgravity environment will help scientists make new discoveries. 26 00:01:47,000 --> 00:01:52,000 But how will microgravity affect the people living onboard the space station? 27 00:01:52,000 --> 00:01:53,000 That's a great question, Jennifer. 28 00:01:53,000 --> 00:02:01,000 The human body reacts immediately and dramatically to the microgravity environment we feel when we go into orbit around the Earth. 29 00:02:01,000 --> 00:02:05,000 Remember how you explained being on the station is like being in a state of free fall? 30 00:02:05,000 --> 00:02:09,000 It feels like there is no gravity. That's why we often call it zero-g. 31 00:02:09,000 --> 00:02:15,000 One of the first reactions of the body to zero-g is to push our internal fluids upward in our body. 32 00:02:15,000 --> 00:02:20,000 You see, on Earth, in one-g, our body works to push the fluids inside upward. 33 00:02:20,000 --> 00:02:24,000 All the water, blood, and other fluids don't collect in your feet. 34 00:02:24,000 --> 00:02:29,000 When the body first experiences zero-g, it continues to push the fluids up, as on Earth, 35 00:02:29,000 --> 00:02:35,000 but since there is no one-g pulling down anymore, the upper body and head ends up with too much fluid. 36 00:02:35,000 --> 00:02:43,000 If you've ever seen pictures of us in space on the first day, our faces are puffed up like chipmunks because of the extra fluid in our upper body. 37 00:02:43,000 --> 00:02:49,000 But the body quickly senses this condition and begins to move the fluids to different parts of the body. 38 00:02:49,000 --> 00:02:56,000 In about two or three days, we reach a new point of balance where our bodies have less fluid in our bloodstream than the average person on Earth. 39 00:02:56,000 --> 00:03:01,000 If you return to Earth's one-g in this state, you would probably faint. 40 00:03:01,000 --> 00:03:05,000 To counteract that, we fluid load just before returning to Earth. 41 00:03:05,000 --> 00:03:11,000 For instance, we drink at least one quart of water within one hour of returning, along with salt tablets, 42 00:03:11,000 --> 00:03:14,000 which keeps the water from passing directly to your bladder. 43 00:03:14,000 --> 00:03:18,000 Wow! Well, how else does microgravity affect the human body? 44 00:03:18,000 --> 00:03:23,000 Well, Van, a longer-term effect, which also begins immediately, is the loss of bone mass. 45 00:03:23,000 --> 00:03:27,000 When you lose bone mass, your bones become brittle and can break very easily. 46 00:03:27,000 --> 00:03:33,000 Anyway, only about 400 humans have flown in space, and only a fraction of them were tested carefully for bone loss. 47 00:03:33,000 --> 00:03:36,000 The numbers so far are startling. 48 00:03:36,000 --> 00:03:40,000 Healthy space travelers lose bone mass ten times faster than people here on Earth. 49 00:03:40,000 --> 00:03:45,000 Whether in space for one week or one year, the rate of bone loss is about the same. 50 00:03:45,000 --> 00:03:49,000 Let me show you how important math is when determining bone loss. 51 00:03:49,000 --> 00:03:53,000 The percent of bone loss is a function of the length of time in space. 52 00:03:53,000 --> 00:04:00,000 l is the percent of bone loss, r is the rate of bone loss per month, and t is the time in space. 53 00:04:00,000 --> 00:04:07,000 So far, the data we've collected tells us that humans in space lose bone mass at a rate of 1% per month. 54 00:04:07,000 --> 00:04:14,000 The function l equals rt tells us that the longer you are in space, the more bone mass you lose. 55 00:04:14,000 --> 00:04:19,000 We have values of t up to 14 months, and the function appears linear. 56 00:04:19,000 --> 00:04:24,000 So far, we haven't had any astronauts in space for more than 14 months. 57 00:04:24,000 --> 00:04:29,000 This rate of bone loss could be a problem if we want to go on a three-year trip to Mars and back. 58 00:04:29,000 --> 00:04:33,000 That trip would cause a bone mass loss of 36%. 59 00:04:33,000 --> 00:04:39,000 Our bones would be so brittle, any type of physical activity would be out of the question. 60 00:04:39,000 --> 00:04:41,000 This is not good news. 61 00:04:41,000 --> 00:04:45,000 But the function would level off eventually with time, and further bone loss would stop. 62 00:04:45,000 --> 00:04:47,000 So how do you measure bone loss? 63 00:04:47,000 --> 00:04:53,000 Well, we measure bone loss by conducting tests like x-rays on the crew, both before and after they fly. 64 00:04:53,000 --> 00:04:56,000 Each person reacts differently to zero-g. 65 00:04:56,000 --> 00:05:03,000 So we need to put the data from many astronauts all together and use statistics to predict the effect on future crew members. 66 00:05:03,000 --> 00:05:08,000 We calculate means, medians, and standard deviation. 67 00:05:08,000 --> 00:05:13,000 Our statistics so far are not that good because we have data on so few people. 68 00:05:13,000 --> 00:05:17,000 You see, when you average data from only a few people out of a large group, 69 00:05:17,000 --> 00:05:22,000 the result from those few people may not match the average of the larger group. 70 00:05:28,000 --> 00:05:34,000 However, if you collect data on hundreds of people, like ground-based medical research does, 71 00:05:34,000 --> 00:05:37,000 the average is more reliable and easier to predict. 72 00:05:38,000 --> 00:05:44,000 Because there are only a handful of good measurements on space flyers, our predicted average is less reliable. 73 00:05:44,000 --> 00:05:47,000 We just need to make many more measurements. 74 00:05:47,000 --> 00:05:50,000 We'll also study why we lose our bone mass. 75 00:05:50,000 --> 00:05:53,000 Then maybe we can develop drugs to stop the effect. 76 00:05:53,000 --> 00:05:58,000 In fact, the National Institutes of Health is working with us on this research. 77 00:05:58,000 --> 00:06:04,000 So you see, research on ISS is not only about improving life in space, but also improving life here on Earth. 78 00:06:04,000 --> 00:06:06,000 Well, thanks so much, Dr. Bartow. 79 00:06:06,000 --> 00:06:07,000 You're very welcome. 80 00:06:07,000 --> 00:06:13,000 Earlier in the program, Jennifer and I said you could see the ISS in the sky from your own backyard. 81 00:06:13,000 --> 00:06:17,000 Visit this website to see if the ISS will be flying over your city.