1 00:00:00,000 --> 00:00:06,000 Shuttle astronauts will visit the Hubble Space Telescope for the final time in May 2009. 2 00:00:06,000 --> 00:00:11,000 In five bold and daring spacewalks, they will upgrade Hubble’s instruments 3 00:00:11,000 --> 00:00:18,000 allowing it to continue making remarkable scientific discoveries well into the next decade. 4 00:00:37,000 --> 00:00:38,000 This is the Hubblecast! 5 00:00:38,000 --> 00:00:42,000 News and images from the NASA/ESA Hubble Space Telescope. 6 00:00:42,000 --> 00:00:48,000 Travelling through time and space with our host Doctor J a.k.a. Dr. Joe Liske. 7 00:00:48,000 --> 00:00:54,000 To scientists and the public alike the NASA/ESA Hubble Space Telescope is an icon of scientific progress. 8 00:00:54,000 --> 00:00:58,000 Although more than 100 space observatories have been put into orbit over the years, 9 00:00:58,000 --> 00:01:00,000 Hubble remains the best known. 10 00:01:00,000 --> 00:01:05,000 Its success story is based on the amazing scientific results and stunning images. 11 00:01:05,000 --> 00:01:11,000 But much of this was only possible because, once in a while, astronauts went up there and paid Hubble a visit. 12 00:01:11,000 --> 00:01:14,000 Welcome to the Hubblecast! 13 00:01:14,000 --> 00:01:20,000 I am actually quite excited because today we are going to look at the fifth - and final - Hubble Servicing Mission. 14 00:01:21,000 --> 00:01:26,000 The NASA/ESA Hubble Space Telescope is a remarkable feat of engineering 15 00:01:26,000 --> 00:01:31,000 that enables scientists to produce the stunning results we have all come to love. 16 00:01:31,000 --> 00:01:36,000 From the very beginning, the design of Hubble allowed the various instruments to be replaced over time, 17 00:01:36,000 --> 00:01:41,000 as scientists on the ground developed new, more powerful instruments. 18 00:01:41,000 --> 00:01:49,000 Now a team of astronauts is making one final journey to Hubble to give it a 100 000 orbit service. 19 00:01:49,000 --> 00:01:52,000 This is the fifth servicing mission to Hubble. 20 00:01:52,000 --> 00:01:55,000 The first took place back in 1993 when, 21 00:01:55,000 --> 00:02:01,000 in a series of landmark spacewalks, astronauts corrected Hubble’s nearsighted vision. 22 00:02:01,000 --> 00:02:11,000 Three further missions in 1997, 1999, and 2002 replaced various instruments and other components on Hubble. 23 00:02:13,000 --> 00:02:17,000 This fifth servicing mission has two main parts: 24 00:02:17,000 --> 00:02:24,000 the first is to install two new instruments and the second is to repair two existing instruments that are already on board Hubble: 25 00:02:24,000 --> 00:02:27,000 the ACS camera and the STIS spectrograph. 26 00:02:27,000 --> 00:02:33,000 The first new instrument, the Wide Field Camera 3, is essentially an improved digital camera – 27 00:02:33,000 --> 00:02:37,000 just the like the ones you and I might use for our holiday snapshots, 28 00:02:37,000 --> 00:02:44,000 except that this one boasts 16-megapixels, can observe in the ultraviolet, visible and infrared regimes, 29 00:02:44,000 --> 00:02:47,000 and it weighs several hundred kilos! 30 00:02:49,000 --> 00:02:53,000 The second new instrument is the Cosmic Origins Spectrograph, which will work in the ultraviolet. 31 00:02:53,000 --> 00:02:57,000 Unlike cameras, a spectrograph don’t take images — 32 00:02:57,000 --> 00:03:03,000 instead it breaks up the light into its constituent colours to show its spectrum, a bit like a rainbow. 33 00:03:05,000 --> 00:03:09,000 Because the new Wide Field Camera 3 images in several colours – 34 00:03:09,000 --> 00:03:17,000 making it the first panchromatic instrument on Hubble - we can learn much about the composition of distant objects. 35 00:03:17,000 --> 00:03:21,000 Ultraviolet light reveals hot young stars burning brightly, 36 00:03:21,000 --> 00:03:29,000 yellow light reveals clouds of hydrogen gas and red light reveals the glowing embers of older stars. 37 00:03:29,000 --> 00:03:32,000 By combining images taken in each colour, 38 00:03:32,000 --> 00:03:38,000 astronomers can see structure within galaxies and begin to learn how it changes over time. 39 00:03:38,000 --> 00:03:43,000 A young proto-galaxy in the early Universe blazes brightly in the ultraviolet. 40 00:03:43,000 --> 00:03:47,000 This light travels for 13 billion years to reach us, 41 00:03:47,000 --> 00:03:52,000 by which time this light is shifted into the red and near-infrared part of the spectrum, 42 00:03:52,000 --> 00:03:56,000 and allows astronomers to see galaxies in the early stages of evolution. 43 00:03:56,000 --> 00:04:00,000 The powerful new Cosmic Origins Spectrograph, 44 00:04:00,000 --> 00:04:06,000 COS, will investigate the gas between galaxies to learn more about its chemical composition 45 00:04:06,000 --> 00:04:08,000 and the early growth of stars in the Universe. 46 00:04:08,000 --> 00:04:15,000 It will do this by looking at how the light from very distant quasars is absorbed as it passes through the gas. 47 00:04:15,000 --> 00:04:20,000 Closer to home, this improved spectrograph can also detect young stars, 48 00:04:20,000 --> 00:04:26,000 burning hotter than our Sun, embedded in the thick dust clouds that gave rise to their birth, 49 00:04:26,000 --> 00:04:29,000 clarifying the phenomenon of star formation. 50 00:04:30,000 --> 00:04:35,000 The second task on this mission is going to be a huge challenge for the astronauts. 51 00:04:35,000 --> 00:04:38,000 They have to repair two instruments that are already on board Hubble, 52 00:04:38,000 --> 00:04:41,000 but which haven’t been working properly for some time now. 53 00:04:41,000 --> 00:04:46,000 The problem is that these instruments were never designed to be repaired in space! 54 00:04:46,000 --> 00:04:52,000 That means that some very clever people had to invent new and dexterous tools to help them carry out the repair. 55 00:04:52,000 --> 00:04:57,000 The second problem is that it is actually not that easy to play electrician in space. 56 00:04:57,000 --> 00:05:00,000 Astronauts wear really thick gloves. 57 00:05:00,000 --> 00:05:05,000 For them, any task is kind of like trying to peel an egg with really thick oven gloves. 58 00:05:10,000 --> 00:05:12,000 …except for them, it will be even harder. 59 00:05:12,000 --> 00:05:17,000 For example, they will have to undo more than one hundred screws without losing any. 60 00:05:17,000 --> 00:05:20,000 I’m sure they’ll be doing a better job than me … 61 00:05:21,000 --> 00:05:25,000 The repaired STIS instrument will obtain spectra from objects – 62 00:05:25,000 --> 00:05:29,000 but at different wavelengths to the new COS instrument. 63 00:05:29,000 --> 00:05:36,000 For the first time, scientists will be able to simultaneously see spectra from across a wide range of wavelengths. 64 00:05:36,000 --> 00:05:40,000 Even with the introduction of the new Wide Field Camera, 65 00:05:40,000 --> 00:05:46,000 the repaired ACS instrument remains Hubble’s most sensitive in the visible-light range. 66 00:05:46,000 --> 00:05:53,000 It will continue to capture stunning images and help scientists unravel the mysteries of the Universe. 67 00:05:53,000 --> 00:05:57,000 In addition to the work on the instruments, Hubble itself will also get a service. 68 00:05:57,000 --> 00:06:00,000 Just like your car, after 100 000 orbits, 69 00:06:00,000 --> 00:06:04,000 Hubble needs the equivalent of an oil change and a new set of tyres. 70 00:06:04,000 --> 00:06:11,000 Astronauts will carry out extra spacewalks to replace some parts that will keep Hubble flying hopefully well into the next decade. 71 00:06:11,000 --> 00:06:19,000 They will also attach a special mechanism that will allow a future robotic spacecraft to dock with Hubble in order to steer it to a peaceful, 72 00:06:19,000 --> 00:06:23,000 final resting place in the ocean when its time has finally come. 73 00:06:24,000 --> 00:06:26,000 Upgrades to the power and guidance systems will give Hubble a new lease of life. 74 00:06:26,000 --> 00:06:36,000 A rejuvenated Hubble will allow astronomers to continue making remarkable discoveries for many years to come. 75 00:06:46,000 --> 00:06:47,000 Impressive, isn’t it? 76 00:06:47,000 --> 00:06:50,000 It looks like this servicing mission is going to make Hubble better than ever. 77 00:06:50,000 --> 00:06:56,000 I’m already looking forward to bringing you the exciting discoveries from these instruments later this year. 78 00:06:56,000 --> 00:07:01,000 Look out for updates on the servicing mission on our website at spacetelescope.org. 79 00:07:01,000 --> 00:07:04,000 This is Dr. J signing off for the Hubblecast. 80 00:07:04,000 --> 00:07:08,000 Once again nature has surprised us beyond our wildest imagination.