1 00:00:00,000 --> 00:00:04,000 We're Miss Kansas' 7th grade math class. 2 00:00:04,000 --> 00:00:08,000 The students at Graham Middle School in Mountain View, California, took the challenge. 3 00:00:08,000 --> 00:00:10,000 Let's see some of their results. 4 00:00:10,000 --> 00:00:13,000 Recall the two questions in this activity. 5 00:00:13,000 --> 00:00:19,000 One, what are the dimensions of a rectangular prism that has a volume of 24 cubic inches, 6 00:00:19,000 --> 00:00:23,000 fits into an 8-inch PSA, and has the maximum surface area? 7 00:00:23,000 --> 00:00:31,000 And two, if the volume stays the same, does a tall cylinder or a wide cylinder have more surface area? 8 00:00:39,000 --> 00:00:40,000 Two inches. 9 00:00:40,000 --> 00:00:42,000 What do you guys think? Is that going to fit? 10 00:00:42,000 --> 00:00:45,000 Remember, our goal is thinking about how to maximize surface area. 11 00:00:45,000 --> 00:00:47,000 The surface area was 77.6. 12 00:00:47,000 --> 00:00:50,000 What are we going to say? What dimensions are we going to recommend? 13 00:00:50,000 --> 00:00:54,000 6 by 5 by 0.8. 14 00:00:54,000 --> 00:00:56,000 So guys, what did you find? 15 00:00:56,000 --> 00:01:00,000 When you flatten a rectangular prism, the surface area increases. 16 00:01:00,000 --> 00:01:05,000 You can get different answers depending on how high you make the rectangular prism. 17 00:01:05,000 --> 00:01:10,000 When the radius increases, the surface area of the cylinder increases. 18 00:01:10,000 --> 00:01:11,000 Okay, let's summarize. 19 00:01:11,000 --> 00:01:17,000 The surface area of a rectangular prism is the sum of the surface area of its six sides. 20 00:01:17,000 --> 00:01:22,000 The volume of a rectangular prism is the length times the width times the height. 21 00:01:22,000 --> 00:01:26,000 A rectangular prism has the minimum surface area when it's a cube, 22 00:01:26,000 --> 00:01:30,000 and the surface area increases as you flatten it. 23 00:01:30,000 --> 00:01:36,000 The surface area of a cylinder is the sum of the areas of the circles at the top and bottom, 24 00:01:36,000 --> 00:01:38,000 and the area of the side. 25 00:01:38,000 --> 00:01:44,000 The volume of a cylinder is the area of the circle at the bottom times the height of the cylinder. 26 00:01:44,000 --> 00:01:51,000 When the volume is the same, a tall cylinder has less surface area than a wide cylinder. 27 00:01:51,000 --> 00:01:56,000 We have to do calculations like this when we lay out the design of all the components of the PSA. 28 00:01:56,000 --> 00:01:59,000 Okay, so Dan, what is the future of the PSA? 29 00:01:59,000 --> 00:02:01,000 Well, once we're able to make the PSA smaller, 30 00:02:01,000 --> 00:02:05,000 we'd like to consider a PSA which could further interact with the spacecraft. 31 00:02:05,000 --> 00:02:12,000 Imagine a PSA with arms that could actually push buttons, retrieve tools, and better interact with the ISS. 32 00:02:12,000 --> 00:02:16,000 Well, developing effective artificial intelligence is a big challenge, 33 00:02:16,000 --> 00:02:19,000 and being able to understand what the astronauts say is especially difficult 34 00:02:19,000 --> 00:02:24,000 because our brains understand things in context or the situation we're in. 35 00:02:24,000 --> 00:02:27,000 Well, a critical part of the future of the PSA is the vision system. 36 00:02:27,000 --> 00:02:32,000 We need vision for everything from navigation and control to identifying hazards 37 00:02:32,000 --> 00:02:36,000 to doing inventory tracking and also to recognize the crew 38 00:02:36,000 --> 00:02:41,000 because we need to customize schedules and training procedures to go with a particular crew member. 39 00:02:41,000 --> 00:02:46,000 And we also use it as sort of remote eyes for the ground folks that are running the operation 40 00:02:46,000 --> 00:02:50,000 so they can inspect the station through the eyes of the PSA. 41 00:02:50,000 --> 00:02:54,000 And being able to interpret what you can see will save us a great deal of time. 42 00:02:56,000 --> 00:03:01,000 My thanks to Yuri, Keith, and Dan for all their information on the PSA. 43 00:03:01,000 --> 00:03:04,000 And don't forget, keep checking the PSA website 44 00:03:04,000 --> 00:03:08,000 for the latest developments on this personal satellite assistant.