Editing Hubble Space Telescope (section)

=== Servicing Mission 1 ===
{{Main|STS-61}}
[[File:Upgrading Hubble during SM1.jpg|thumb|right|Astronauts Musgrave and Hoffman install corrective optics during SM1]]

The first Hubble servicing mission was scheduled for 1993 before the mirror problem was discovered. It assumed greater importance, as the astronauts would need to do extensive work to install corrective optics; failure would have resulted in either abandoning Hubble or accepting its permanent disability. Other components failed before the mission, causing the repair cost to rise to $500&nbsp;million (not including the cost of the shuttle flight). A successful repair would help demonstrate the viability of building [[Space Station Alpha]].{{sfn|Tatarewicz|1998|pp=374,378,381,388}}

[[STS-49]] in 1992 demonstrated the difficulty of space work. While its rescue of [[Intelsat 603]] received praise, the astronauts had taken possibly reckless risks in doing so. Neither the rescue nor the unrelated assembly of prototype space station components occurred as the astronauts had trained, causing NASA to reassess planning and training, including for the Hubble repair. The agency assigned to the mission [[Story Musgrave]]—who had worked on satellite repair procedures since 1976—and six other experienced astronauts, including two from STS-49. The first mission director since [[Project Apollo]]{{clarify|date=August 2023}} would coordinate a crew with 16 previous shuttle flights. The astronauts were trained to use about a hundred specialized tools.{{sfn|Tatarewicz|1998|pp=380-381,384–387}}

Heat had been the problem on prior spacewalks, which occurred in sunlight. Hubble needed to be repaired out of sunlight. Musgrave discovered during vacuum training, seven months before the mission, that spacesuit gloves did not sufficiently protect against the cold of space. After [[STS-57]] confirmed the issue in orbit, NASA quickly changed equipment, procedures, and flight plan. Seven total mission simulations occurred before launch, the most thorough preparation in shuttle history. No complete Hubble mockup existed, so the astronauts studied many separate models (including one at the Smithsonian) and mentally combined their varying and contradictory details.{{sfn|Tatarewicz|1998|pp=384–387}}

Service Mission 1 flew aboard [[Space Shuttle Endeavour|''Endeavour'']] in December 1993, and involved installation of several instruments and other equipment over ten days. Most importantly, the [[High Speed Photometer]] was replaced with the [[Corrective Optics Space Telescope Axial Replacement|COSTAR]] corrective optics package, and WF/PC was replaced with the [[Wide Field and Planetary Camera 2]] (WFPC2) with an internal optical correction system. The [[Photovoltaic module|solar arrays]] and their drive electronics were also replaced, as well as four gyroscopes in the telescope pointing system, two electrical control units and other electrical components, and two magnetometers. The onboard computers were upgraded with added [[coprocessor]]s, and Hubble's orbit was boosted.<ref name="Servicing Mission 1" />

On January 13, 1994, NASA declared the mission a complete success and showed the first sharper images.<ref>{{cite journal |title=The on-orbit performance of WFPC2 |journal=Astrophysical Journal Letters |first1=J. T. |last1=Trauger |first2=G. E. |last2=Ballester |first3=C. J. |last3=Burrows |first4=S. |last4=Casertano |first5=J. T. |last5=Clarke |first6=D. |last6=Crisp |first7=R. W. |last7=Evans |first8=J. S. |last8=Gallagher III |first9=R. E. |last9=Griffiths |display-authors=4 |volume=435 |pages=L3–L6 |date=1994 |bibcode=1994ApJ...435L...3T |doi=10.1086/187580 |url=https://authors.library.caltech.edu/53641/ |access-date=January 7, 2022 |archive-date=January 7, 2022 |archive-url=https://web.archive.org/web/20220107163225/https://authors.library.caltech.edu/53641/ |url-status=live }}</ref> The mission was one of the most complex performed to that date, involving five long [[extra-vehicular activity]] periods. Its success was a boon for NASA, as well as for the astronomers who now had a more capable space telescope.<ref name=":2" /><ref>{{Cite web |last=DeVorkin |first=David |date=April 24, 2020 |title=Telling Hubble's Story for 30 Years |url=https://airandspace.si.edu/stories/editorial/telling-hubbles-story-30-years |access-date=April 7, 2022 |website=National Air and Space Museum |publisher=Smithsonian Institution |language=en |archive-date=December 31, 2021 |archive-url=https://web.archive.org/web/20211231011831/https://airandspace.si.edu/stories/editorial/telling-hubbles-story-30-years |url-status=live }}</ref>