Editing Hubble Space Telescope (section)

=== Servicing overview ===
<!-- Subheading above added to ease editing of the timeline defined below. -->
<div style="float: right; clear: right; margin: 0 0 1em 1em; padding: 3px;">
<timeline>
# see [[Help:EasyTimeline syntax]]
# consider converting this to a template 
ImageSize = width:420 height:200    # increase height to allow for title text/legend
PlotArea  = width:400 height:140 left:10 bottom:20   # width & height should no longer be used - chg to  top:40 right:10 
AlignBars = justify # no space above or below

TextData =  # legend might be better
  fontsize:M
  pos:(50,190)  # top, above bars
  text:Instruments installed in the radial bay and 4 axial bays
  
Colors =
  id:lightGray     value:gray(0.999999)
  id:darkGray      value:gray(0.2)
  id:ren      value:rgb(0.6,1,1)   # cyan
  id:bar      value:rgb(0.6,1,0.6) # apple greem
  id:cla      value:rgb(1,1,0.6)   # custard yellow
 id:lightred2 value:rgb(1,0.9,0.9) # pink

BackgroundColors= canvas:lightGray

Period     = from:1990 till:2022
TimeAxis   = orientation:horizontal
ScaleMajor = unit:year increment:5 start:1990 gridcolor:darkgray
ScaleMinor = unit:year increment:1 start:1990
# default DateFormat = x.y  (year.decimal?)
# SM1 was Dec 1993 (1993.9), SM2...  SM4 was May 2009 (2009.4)

# So timeline autoextends, Consider using 
# Period     = from:1990 till:{{#expr:{{#time:Y}}+{{#time:m}}/12}}

PlotData=
  align:left  anchor:from  shift:(10,-4)  # bar label text, start at left end, centred vertically

  bar:&nbsp;

   from:1990 till:1993.9 color:Ren text:[[Wide Field and Planetary Camera|WFPC]]
   from:1993.9 till:2009.4 color:Bar text:[[Wide Field and Planetary Camera 2|WFPC2]]
   from:2009.4 till:end color:Cla text:[[Wide Field Camera 3|WFC3]]

  bar:&nbsp;&nbsp;

   from:1990 till:1997 color:Ren text:[[Goddard High Resolution Spectrograph|GHRS]]
   from:1997 till:2008 color:Bar text:[[Near Infrared Camera and Multi-Object Spectrometer|NICMOS]]
   from:2008 till:end color:lightred2 text:NICMOS Offline

  bar:&nbsp;&nbsp;&nbsp;

   from:1990 till:1993.9 color:Ren text:[[High Speed Photometer|HSP]]
   from:1993.9 till:2009.4 color:Bar text:[[Corrective Optics Space Telescope Axial Replacement|COSTAR]]
   from:2009.4 till:end color:Cla text:[[Cosmic Origins Spectrograph|COS]]

  bar:&nbsp;&nbsp;&nbsp;&nbsp;

   from:1990 till:2002 color:Ren text:[[Faint Object Camera|FOC]]
   from:2002 till:end color:Bar text:[[Advanced Camera for Surveys|ACS]]

  bar:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

   from:1990 till:1997 color:Ren text:[[Faint Object Spectrograph|FOS]]
   from:1997 till:2004.7 color:Bar text:[[Space Telescope Imaging Spectrograph|STIS]]
   from:2004.7 till:2009.4 color:lightred2 text:failed
   from:2009.4 till:end color:Bar text:[[Space Telescope Imaging Spectrograph|STIS]]

</timeline>
</div>

Hubble was designed to accommodate regular servicing and equipment upgrades while in orbit. Instruments and limited life items were designed as [[orbital replacement unit (HST)|orbital replacement units]].<ref>{{Cite web |date=2013-02-19 |title=Hubble Space Telescope (HST) Archive System |url=http://setas-www.larc.nasa.gov/HUBBLE/HARDWARE/hubble_ORU.html |access-date=2024-01-31 |archive-url=https://web.archive.org/web/20130219022932/http://setas-www.larc.nasa.gov/HUBBLE/HARDWARE/hubble_ORU.html |archive-date=February 19, 2013 }}</ref> Five servicing missions (SM 1, 2, 3A, 3B, and 4) were flown by NASA [[Space Shuttle]]s, the first in December 1993 and the last in May 2009.<ref name="hubble-timeline">{{cite web |url=https://www.nationalgeographic.com/hubble-timeline/ |title=The Secret to Hubble's Success |work=National Geographic |first1=Jason |last1=Treat |first2=Anna |last2=Scalamogna |first3=Eve |last3=Conant |date=2015 |access-date=April 25, 2015 |archive-date=April 28, 2015 |archive-url=https://web.archive.org/web/20150428040059/http://www.nationalgeographic.com/hubble-timeline/ |url-status=live }}</ref> Servicing missions were delicate operations that began with maneuvering to intercept the telescope in orbit and carefully retrieving it with the shuttle's [[Canadarm|mechanical arm]]. The necessary work was then carried out in multiple tethered [[spacewalk]]s over a period of four to five days. After a visual inspection of the telescope, astronauts conducted repairs, replaced failed or degraded components, upgraded equipment, and installed new instruments. Once work was completed, the telescope was redeployed, typically after boosting to a higher orbit to address the [[orbital decay]] caused by atmospheric [[drag (physics)|drag]].<ref name="nytimes20150424">{{cite web |url=https://www.nytimes.com/video/science/100000003647066/hubble-reflects-the-cosmos.html |title=Hubble Reflects the Cosmos |work=The New York Times |first1=Jason |last1=Overbye |first2=Jonathan |last2=Corum |first3=Jason |last3=Drakeford |date=April 24, 2015 |access-date=April 25, 2015 |archive-date=February 2, 2019 |archive-url=https://web.archive.org/web/20190202112051/https://www.nytimes.com/video/science/100000003647066/hubble-reflects-the-cosmos.html |url-status=live }}</ref>