1 00:00:13,889 --> 00:00:18,630 The 18 segments making up the primary mirror on the James Webb Space Telescope will be 2 00:00:18,630 --> 00:00:21,759 held in place by something called a backplane. 3 00:00:21,759 --> 00:00:25,380 Since there are 18 hexagonal mirrors, each being about 3 feet tall. 4 00:00:25,380 --> 00:00:30,000 You can imagine the backplane is huge and very complicated to make. 5 00:00:30,000 --> 00:00:36,040 To find out more about how it's being assembled, we came to Magna, Utah and ATK and we're happy 6 00:00:36,040 --> 00:00:41,010 to have with us, Bob Hellickson, the Project Manager for the James Webb Space Tele- scope. 7 00:00:41,010 --> 00:00:42,010 Thanks for having us over. 8 00:00:42,010 --> 00:00:43,800 Thanks for coming to visit us Mary. 9 00:00:43,800 --> 00:00:49,090 First of all, how tough a job is it to make a backplane for the James Webb Space Telescope? 10 00:00:49,090 --> 00:00:54,059 Well, what we're standing in front of right here, is three of the full scale hexes for 11 00:00:54,059 --> 00:00:58,679 the backplane and this was manufactured out of wood that established both the tooling 12 00:00:58,679 --> 00:01:02,980 approach and the assem- bly approach for the flight article. 13 00:01:02,980 --> 00:01:05,519 Now you didn't just go from this to the real thing, did you? 14 00:01:05,519 --> 00:01:07,490 No, we did not as a matter of fact. 15 00:01:07,490 --> 00:01:09,730 This structure was the first, made out of wood. 16 00:01:09,730 --> 00:01:14,660 Then this size, three hexes, was made out of the graphite composite material. 17 00:01:14,660 --> 00:01:21,689 It was taken down to the 30 Kelvin level or minus 405 degrees Fahrenheit and it was measured 18 00:01:21,689 --> 00:01:23,640 for its performance on stability. 19 00:01:23,640 --> 00:01:28,250 It has to stay very stable throughout that entire temperature regime. 20 00:01:28,250 --> 00:01:32,689 So, Bob, I understand the real backplane is here at ATK now? 21 00:01:32,689 --> 00:01:33,689 Oh absolutely! 22 00:01:33,689 --> 00:01:34,689 We can show you that. 23 00:01:34,689 --> 00:01:36,439 We'll have to go to the cleanroom next. 24 00:01:36,439 --> 00:01:43,009 I want to show you some electronic measuring equipment to make sure everything meets its 25 00:01:43,009 --> 00:01:46,360 final dimensional performance before we deliver. 26 00:01:46,360 --> 00:01:50,610 So, is it like a GPS where it detects where that position, where that ball is located 27 00:01:50,610 --> 00:01:51,690 at any given time? 28 00:01:51,690 --> 00:01:53,210 Yeah, that's exactly right. 29 00:01:53,210 --> 00:01:58,899 That ball coordinates back on its surface to where the model is for the corresponding 30 00:01:58,899 --> 00:01:59,899 feature. 31 00:01:59,899 --> 00:02:01,210 This is very interesting stuff. 32 00:02:01,210 --> 00:02:02,370 The suspense is killing me. 33 00:02:02,370 --> 00:02:04,009 Can we see the backplane now? 34 00:02:04,009 --> 00:02:08,380 Bob: Absolutely, step around this side and we'll show you the rest of it. 35 00:02:08,380 --> 00:02:09,380 Great. 36 00:02:09,380 --> 00:02:14,310 This is the center section of the backplane and it will house 12 of the primary mirror 37 00:02:14,310 --> 00:02:15,310 segments. 38 00:02:15,310 --> 00:02:16,930 Mary: Now you said center section. 39 00:02:16,930 --> 00:02:18,570 It's not the whole thing? 40 00:02:18,570 --> 00:02:19,570 Correct. 41 00:02:19,570 --> 00:02:25,170 The full sized mirror will have 18 segments and what's missing here, they'll come later... 42 00:02:25,170 --> 00:02:28,700 are two wings, each one holding 3 segments, or 3 mirrors. 43 00:02:28,700 --> 00:02:31,480 And why break it out into a center and two wings. 44 00:02:31,480 --> 00:02:32,780 The launch vehicles cannot... 45 00:02:32,780 --> 00:02:35,920 don't have the dimensions to accept the entire width. 46 00:02:35,920 --> 00:02:37,230 So it has to fold up. 47 00:02:37,230 --> 00:02:42,500 And that's another unique feature here as we're deploying three of the hexes on each 48 00:02:42,500 --> 00:02:43,910 side or on both wings. 49 00:02:43,910 --> 00:02:48,030 So, Bob, I noticed this isn't exactly a flat structure. 50 00:02:48,030 --> 00:02:49,989 It's got a little bit of a curve. 51 00:02:49,989 --> 00:02:50,989 That's correct. 52 00:02:50,989 --> 00:02:55,180 The backplane matches the parabolic shape they want the primary mirror to end up with 53 00:02:55,180 --> 00:02:56,180 so it's actually curved to match that desired outcome. 54 00:02:56,180 --> 00:03:00,330 Besides holding the mirrors in place once James Webb is in operation, what else in the 55 00:03:00,330 --> 00:03:01,380 back- plane for? 56 00:03:01,380 --> 00:03:06,530 The backplane also provides stability for the entire observatory, so what's missing 57 00:03:06,530 --> 00:03:13,720 here, you'll see later is the backplane stability frame, reaches about 8 feet off of this section. 58 00:03:13,720 --> 00:03:19,910 It will house the instruments for the observatory and provides a lot of the strength for the 59 00:03:19,910 --> 00:03:21,680 launch. 60 00:03:21,680 --> 00:03:23,409 Well thanks for showing us ATK's backplane. 61 00:03:23,409 --> 00:03:26,440 Bob: Well, thanks for coming to visit us, Mary. 62 00:03:26,440 --> 00:03:32,700 So, as you can see, this backplane will ultimately be thermally and structurally stable. 63 00:03:32,700 --> 00:03:38,600 Im- portant for the 18 segment primary mirror to stay still so that the James Webb Space 64 00:03:38,600 --> 00:03:42,209 Telescope can take it's wonderful images of the universe.