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9/6/23, 4.14 PM Case Study 1: Hubble Space Telescope Case Study 1: Hubble Space Telescope 10 Possible Points 9/7/2023 In Progress NEXT UP: Submit Assignment GN Add Comment Attempt 1 Vv Unlimited Attempts Allowed 8/29/2023 to 9/14/2023 v Details » Objective: The objective of the Case Study is to learn about complex product malfunctions/failures, reflect upon what happened and how it could be improved/avoided with Systems Engineering. Exercise: Please read this Hubble Case Study. (https://umich.instructure.com/courses/621968/files/31253992/download?wrap=1)_ -\, (https://umich.instructure.com/courses/621968/files/31253992/download?download_frd=1) You may use any additional resources (books, library, internet) to learn more about the case. Enclose below is a dramatic account of what happened from CIlO. Please paste the following link in your browser: https://d2r9nfiii89r0l.cloudfront.net/article/420036/what_went_wrong_hubble space_telescope what _managers can_learn_from it /? Enclosed below is a third shorter writeup on this issue from newscientist.com: NASA has established how a mirror aboard its $1.5 billion Hubble Telescope came to be the wrong shape. The agency said last week that errors in a test instrument apparently led Perkin-Elmer, which fabricated the optics, to finish the 2.4-metre primary mirror of the Hubble Space Telescope incorrectly. Tests by NASA earlier this month showed that a lens in the test instrument, called the ‘reflective null corrector’, is about a millimetre askew. Preliminary analysis indicates that an error of this magnitude could cause the spherical aberration that prevents Hubble from focusing sharply. The crucial error, the misalignment of a lens by a millimetre, is ‘very large’ by optical standards, says Daniel Schroeder, an astronomer at Beloit College in Wisconsin, and a codesigner of Hubble. In some optical instruments, positions are measured to a fraction of the wavelength of light, less than a thousandth of a millimetre. Ironically, Perkin- Elmer ignored warnings of the problem detected by a cruder test instrument. NASA says that it trusted the refractive null corrector because it had been ‘certified’ for final tests of the mirror’s shape. Perkin-Elmer, which built Hubble at its Danbury plant in Connecticut, tested the primary and secondary mirrors separately, but no one tested the complete telescope before launch. An earlier check by NASA absolved the design itself of blame, leading the agency to narrow the inquiry to possible errors in the testing of the mirrors. The reflective null corrector is a cylinder 76 centimetres high and about half a metre wide. It contains two mirrors and a lens, made specifically to test the Hubble primary. By passing light between two mirrors and through a field lens, the instrument should have generated a wavefront matching the desired shape of the primary mirror. The mirror was finished to match the wavefront, so errors in the corrector meant that the final mirror had the wrong shape. After the primary was polished and coated in 1981, the reflective null corrector stayed ‘essentially unchanged’ at the Danbury plant, which Perkin-Elmer sold to Hughes Aircraft last year. NASA is continuing its tests of the instrument. Its investigation board will now concentrate on improving measurements of the error, and on checking for other possible errors. The panel was due to meet this week in Danbury to review testing procedures and data. Ironically, builders of large ground-based telescopes normally test mirrors two or three different ways, and continue testing until results agree. Crucially, Perkin-Elmer ignored tests with a smaller ‘refractive’ null corrector which used lenses rather than mirrors. NASA says the refractive instrument was ‘much cruder’, and that — unlike the reflective null corrector — it was neither ‘certified’ to measure spherical aberration, nor intended for precise measurement of the final surface figure. It now appears that the cruder instrument gave the correct result. Enclosed is a second, more dramatic, account from CIO: https://umich.instructure.com/courses/621968/assignments/2081270 1/3
9/6/23, 4:14 PM Case Study 1: Hubble Space Telescope Submission: Answer each of the following four questions. (You should only need to write about 400-500 words to answer all four questions. ). After each question, the guideline for a full credit for your answer is written in red: e Q1: What happened? (Summarize the case): Please do not use more than 300 (and ideally less) words. Should include a brief summary of the incident background, chronology, and root cause. e Q2: What went right with the Hubble Telescope from a systems engineering perspective? Please provide a bulleted list of responses. You can provide as many responses as you wish. You do not need to provide a rationale. Provide at least the minimum amount of argument needed (the minimum amount varies for every case study). e Q3: What went wrong with the Hubble Telescope from a systems engineering perspective? o Please provide a bulleted list of responses. You can provide as many responses as you wish. For Q2 and Q3, there is a long list of preferred responses. You will be given credit for how many responses (up to four) match this list. You do not have to provide the same number of responses to Q2 as you provide to Q3. Provide at least the minimum amount of argument needed (the minimum amount varies for every case study). e Q4: What corrective actions did the organization take? Please provide a bulleted list of responses. There is one preferred response and you will be given credit based on whether you provide that preferred response. With respect to this case, corrective actions are measures taken by the organization after the failure has occurred, to rectify the error. o References: There is no preferred format. Simply provide enough information so that we can go to the reference for further information. Must be given to verify your arguments. Please include your name in the Header. Make sure to use systems engineering concepts talked about in class to analyze the problem. Please do not procrastinate; start working on the case studies as early as possible. Choose a submission type o Upload Google Drive More O D IO <A Choose a file to upload or https://umich.instructure.com/courses/621968/assignments/2081270 2/3
9/6/23, 4.14 PM Case Study 1: Hubble Space Telescope (0] Webcam Photo ] Canvas Files https://umich.instructure.com/courses/621968/assignments/2081270 3/3
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