Editing STS-133

{{Infobox spaceflight
| name                  = STS-133
| image                 = 521430main iss026e030308 hires.jpg
| image_caption         = Backdropped by Earth, ''Discovery'' approaches the ISS during rendezvous & docking operations.
| insignia              = STS-133 patch.png

| spacecraft            = {{OV|103}}
| mission_type          = ISS assembly
| operator              = [[NASA]]
| COSPAR_ID             = 2011-008A
| SATCAT                = 37371
| orbits_completed      = 
| distance_travelled    = {{convert|5304140|mi|km|disp=flip}}
| mission_duration      = 12 days, 19 hours, 4 minutes, 50 seconds
| launch_mass           = Orbiter: {{convert|268620|lbs|kg|disp=flip}}<br/>Stack: {{convert|4525220|lbs|kg|disp=flip}}
| dry_mass              = {{convert|204736|lbs|kg|disp=flip}}<ref name="press kit">{{Cite web|url=http://www.nasa.gov/pdf/491387main_STS-133%20Press%20Kit.pdf|title=STS-133 Press Kit|accessdate=21 October 2010|publisher=NASA}}</ref>
| landing_mass          = 
| payload_mass          =

| launch_site           = [[Kennedy Space Center|Kennedy]] [[Kennedy Space Center Launch Complex 39|LC-39A]]
| launch_date           = {{start-date|24 February 2011, 21:53:24|timezone=yes}}&nbsp;UTC<ref name=nasalive>{{cite web|title=NASA TV "Live Events, Mission Coverage" [STS-133]|url=http://www.nasa.gov/multimedia/nasatv/index.html|publisher=NASA TV|accessdate=25 February 2011|date=24,25 February 2011}}</ref><ref>{{cite web|title=Twitter / NASA:|url=http://twitter.com/nasa/status/40894734457245696|publisher=NASA|accessdate=24 February 2011|date=24 February 2011}}</ref><ref>{{cite web|title=Discovery in Orbit|url=http://www.nasa.gov/mission_pages/shuttle/main/rss_feed_above_snip_collection_archive_1.html|publisher=NASA|accessdate=24 February 2011|date=24 February 2011}}</ref>

| landing_date          = {{end-date|9 March 2011, 16:58:14|timezone=yes}}&nbsp;UTC
| landing_site          = [[Kennedy Space Center|Kennedy]] [[Shuttle Landing Facility|SLF Runway&nbsp;15]]

| crew_size             = 6
| crew_members          = [[Steven Lindsey]]<br/>[[Eric Boe]]<br/>[[Nicole Stott]]<br/>[[Alvin Drew]]<br/>[[Michael Barratt (astronaut)|Michael Barratt]]<br/>[[Stephen Bowen (astronaut)|Stephen Bowen]]
| crew_photo            = STS-133 Official Crew Photo.jpg
| crew_photo_caption    = From left to right: Alvin Drew, Nicole Stott, Eric Boe, Steven Lindsey, Michael Barratt and Steve Bowen

| docking               ={{Infobox spaceflight/Dock
   |docking_target      = [[International Space Station|ISS]]
   |docking_type        = dock
   |docking_port        = [[PMA-2]]<br/><small>(Harmony forward)</small>
   |docking_date        = 26 February 2011, 19:14 UTC
   |undocking_date      = 7 March 2011, 12:00 UTC
   |time_docked         = 8&nbsp;days, 16&nbsp;hours, 46&nbsp;minutes
}}

| apsis                 = gee
| orbit_epoch           = 25 February 2011<ref name="SATCAT">{{cite web|url=http://planet4589.org/space/log/satcat.txt|title=Satellite Catalog|first=Jonathan|last=McDowell|work=Jonathan's Space Page|accessdate=28 May 2013}}</ref>
| orbit_reference       = [[geocentric orbit|Geocentric]]
| orbit_regime          = [[Low Earth orbit|Low Earth]]
| orbit_periapsis       = {{convert|208|km}}<ref name="SATCAT"/>
| orbit_apoapsis        = {{convert|232|km}}<ref name="SATCAT"/>
| orbit_period          = 88.89 minutes<ref name="SATCAT"/>
| orbit_inclination     = 51.6 degrees<ref name="SATCAT"/>

| programme             = [[Space Shuttle program]]
| previous_mission      = [[STS-132]]
| next_mission          = [[STS-134]]
}}
'''STS-133''' ([[Assembly of the International Space Station#Assembly sequence|ISS assembly]] flight '''ULF5''')<ref name="manifest">{{Cite web|url=http://www.nasa.gov/mission_pages/station/structure/iss_manifest.html|title=Consolidated Launch Manifest|accessdate=16 October 2009|publisher=NASA|date=24 September 2009|author=NASA}}</ref> was the 133rd mission in [[NASA]]'s [[Space Shuttle program]]; during the mission, [[Space Shuttle Discovery|Space Shuttle ''Discovery'']] docked with the [[International Space Station]]. It was ''Discovery''<nowiki>'</nowiki>s 39th and final mission. The mission launched on 24 February 2011, and landed on 9 March 2011. The crew consisted of six American [[astronaut]]s, all of whom had been on prior spaceflights, headed by Commander [[Steven W. Lindsey|Steven Lindsey]]. The crew joined the long-duration six person crew of [[Expedition 26]], who were already aboard the space station.<ref name="sched">{{Cite web|url=http://www.nasa.gov/missions/highlights/schedule.html|title=NASA's Shuttle and Rocket Missions |accessdate=15 October 2009|publisher=[[NASA]]|date=14 October 2009|author=NASA}}</ref> About a month before lift-off, one of the original crew members, [[Timothy L. Kopra|Tim Kopra]], was injured in a bicycle accident. He was replaced by [[Stephen G. Bowen|Stephen Bowen]].

The mission transported several items to the space station, including the [[Leonardo (ISS module)|Permanent Multipurpose Module]] ''Leonardo'', which was left permanently docked to one of the station's ports. The shuttle also carried the third of four [[ExPRESS Logistics Carrier]]s to the ISS, as well as a [[humanoid robot]] called [[Robonaut]].<ref>{{Cite web|url=http://www.outerspaceuniverse.org/last-flight-of-space-shuttle-discovery-sts-133.html|title=Last Flight of Space Shuttle Discovery STS-133 |accessdate=February 2011|publisher=Outer Space Universe|date=19 February 2011}}</ref> The mission marked both the 133rd flight of the Space Shuttle program and the 39th and final flight of ''Discovery'', with the orbiter completing a cumulative total of a whole year (365 days) in space.

The mission was affected by a series of delays due to technical problems with the external tank and, to a lesser extent, the payload. The launch, initially scheduled for September 2010, was pushed back to October, then to November, then finally to February 2011.

==Mission payload==

===Permanent Multipurpose Module===
{{main|Permanent Multipurpose Module}}
[[File:STS 133 PMM Leonardo.jpg|right|thumb|PMM ''Leonardo'' at the [[Space Station Processing Facility]] (SSPF).]]
STS-133 left ''Leonardo'' (named after the famed Italian Renaissance inventor [[Leonardo da Vinci]]), one of the three [[Multi-Purpose Logistics Module]]s (MPLMs), on the space station as a [[Permanent Multipurpose Module]] (PMM).<ref name="permanent">{{cite news|url=http://www.nasaspaceflight.com/2009/08/sts-133-five-crew-one-eva-mission-leave-mpm-on-iss|title=STS-133 refined to a five crew, one EVA mission – will leave MPLM on ISS|publisher=NASAspaceflight.com|last=Gebhardt|first=Chris|date=5 August 2009}}</ref><ref name="PMM">{{Cite web|url=http://www.nasa.gov/home/hqnews/2010/feb/HQ_10-044_PMM.html|title=NASA and Italian Space Agency Find New Use for Module|accessdate=26 February 2010|publisher=NASA|date=26 February 2010|author=NASA}}</ref> PMM ''Leonardo'' added much-needed storage space on the ISS, and was launched with a near-full load of payloads.

The construction of the ''Leonardo'' MPLM by the Italian Space Agency commenced in April 1996. In August 1998, after the completion of primary construction, ''Leonardo'' was delivered to the Kennedy Space Center (KSC). In March 2001, ''Leonardo'' made its first mission on ''Discovery'' as part of the [[STS-102]] flight. The liftoff of ''Leonardo'' inside ''Discovery'''s payload bay on STS-102 marked the first of seven MPLM flights prior to STS-133.

With the landing of ''Discovery'' after the [[STS-131]] mission, ''Leonardo'' was transferred back to the Space Station Processing Facility at Kennedy Space Center. ''Leonardo'' began receiving modifications and reconfigurations immediately to convert it for permanent attachment to the space station and to facilitate on-orbit maintenance.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/10/pmm-leonardo-final-permanent-us-module-iss/|title=PMM Leonardo: The Final Permanent U.S. Module for the ISS
|author=Chris Gebhardt|date=6 October 2010|accessdate=15 November 2010|publisher=NASAspaceflight.com}}</ref> Some equipment was removed to reduce the overall weight of ''Leonardo''. These removals resulted in a net weight loss of {{convert|178.1|lbs|kg|abbr=on}}. Additional modifications to ''Leonardo'' included the installation of upgraded [[multi-layer insulation]] (MLI) and [[Whipple shield|Micro Meteoroid Orbital Debris]] (MMOD) shielding to increase the ability of the PMM to handle potential impacts of [[micrometeoroid]]s or [[orbital debris]]; a Planar Reflector was installed at the request of the [[JAXA|Japanese Space Agency]] (JAXA).

Following berthing to the space station, the contents of ''Leonardo'' were emptied and moved to appropriate locations on the ISS. Once JAXA's [[Kounotori 2]] (HTV-2) arrived in February 2011, ''Leonardo'''s now-unnecessary launch hardware was transferred to HTV2 for ultimate destruction in Earth's atmosphere.

Activities to reconfigure ''Leonardo'' following STS-133 spanned multiple station crew increments.

===ExPRESS Logistics Carrier 4===
{{main|Express Logistics Carrier}}
[[File:STS133 ELC-4.jpg|left|thumb|140px|ELC-4 being lifted from its work stand in the SSPF.]]
[[File:ELC-4 STS-133 Launch Config.jpg|thumb|ELC-4 in its launch configuration]]The [[Express Logistics Carrier]] (ELC) is a platform designed to support external payloads mounted to the space station starboard and port trusses with either deep space or Earthward views. On STS-133, ''Discovery'' carried the ELC-4 to the station to be positioned on the starboard 3 (S3) truss' lower inboard passive attachment system (PAS). The total weight of the ELC-4 is approximately 8,235 pounds.

The Express Logistics Carrier 4 (ELC-4) carried several Orbital Replacement Units (ORUs). Among these were a Heat Rejection System Radiator (HRSR) Flight Support Equipment (FSE), which takes up one whole side of the ELC. The other primary ORUs were the ExPRESS Pallet Controller Avionics 4 (ExPCA #4). The HRSR launching on ELC4 was a spare, if needed, for one of the six radiators that are part of the station's external active thermal control system.

===Robonaut2===
{{main|Robonaut}}
[[File:STS133 Crew and Robonaut2.jpg|right|thumb|Robonaut2 and STS-133 crew members pose for a picture near a Destiny lab trainer. (Photo includes original crew member Tim Kopra, who was later replaced by Stephen Bowen)]]
''Discovery'' carried the [[humanoid robot]] [[Robonaut#Latest design .28R2.29|Robonaut2]] (also known as R2) to the [[International Space Station]] (ISS). The microgravity conditions aboard the space station provide an ideal opportunity for robots like R2 to work with astronauts. Although the robot's primary initial task is teaching engineers how dexterous robots behave in space, it may eventually, through upgrades and advancements, assist spacewalking astronauts to perform scientific work once it has been verified as functional on the space station.<ref name=robonaut>{{cite web|url=http://www.engadget.com/2010/04/14/nasa-and-gms-humanoid-robotnaut2-blasting-into-space-this-septe/|title=NASA and GM's humanoid Robonaut2 blasting into space this September|last=Stevens|first=Tim|date=14 April 2010}}</ref> It was the first humanoid robot in space, and was stowed on board the ''Leonardo'' PMM. Once Robonaut2 was unpacked, it began initial operation inside the ''Destiny'' module for operational testing, but over time, both its location and its applications could expand.

Robonaut2 was initially designed as a prototype to be used on Earth. For its journey to the ISS, R2 received a few upgrades. Outer skin materials were exchanged to meet the ISS's strict flammability requirements. Shielding was added to reduce electromagnetic interference and onboard processors were upgraded to increase R2's radiation tolerance. The original fans were replaced with quieter ones to accommodate the station's restrictive noise environment, and the power system was rewired to run on the station's direct current system. Tests were conducted to make sure the robot could both endure the harsh conditions in space and exist in it without doing damage. R2 also underwent vibration testing that simulated the conditions it would experience during its launch onboard ''Discovery''.

The robot weighs 300 pounds (132&nbsp;kg) and is made out of nickel-plated carbon fiber and aluminum. The height of R2 from waist to head is 3 feet, 3.7&nbsp;inches (100&nbsp;cm), and it has a shoulder width of 2 feet, 7.4&nbsp;inches(80&nbsp;cm). R2 is equipped with 54 servo motors and has 42 degrees of freedom.<ref>{{Cite web|url=http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100039862_2010042072.pdf|title=Robonaut 2 (R2) Overview|author=Ron Diftler|publisher=NASA|date=18 November 2010|accessdate=12 December 2010}}</ref> Powered by 38 [[PowerPC]] processors, R2's systems run at 120 volts DC.

===SpaceX DragonEye sensor===
[[File:DragonEye on STS-133.jpg|left|thumb|The DragonEye sensor, as seen by an Expedition 26 crew member]]
Space Shuttle ''Discovery'' also carried the Developmental Test Objective (DTO) 701B payload using Advanced Scientific Concepts, Inc.'s DragonEye 3D Flash light intensification detection and ranging ([[LIDAR]]) sensor. The addition of the pulsed laser navigation sensor was the third time a Space Shuttle provided assistance to the commercial space company [[SpaceX]], following [[STS-127]] and [[STS-129]]. The DragonEye on STS-133 incorporated several design and software improvements from the version flown on STS-127 to provide increased performance. Its inclusion on STS-133 was part of a final test run ahead of being fully implemented on SpaceX's [[SpaceX Dragon|Dragon spacecraft]], which had its maiden flight in December 2010.<ref>{{cite web|url = http://www.dailymail.co.uk/sciencetech/article-1336868/SpaceX-Dragon-privately-funded-spaceship-launched-orbit.html| title = Mission accomplished! SpaceX Dragon becomes the first privately funded spaceship launched into orbit and guided back to earth|first = Daniel|last = Bates|date = 9 December 2010|work=Daily Mail  |location=UK |accessdate =9 December 2019}}</ref>

The navigation sensor provides a three-dimensional image based on the time of flight of a single laser pulse from the sensor to the target and back. It provides both range and bearing information from targets that can reflect the light back such as the pressurized mating adapter 2 (PMA2) and those on the station's Japanese ''Kibo'' laboratory.

The DragonEye DTO was mounted onto ''Discovery''<nowiki>'</nowiki>s existing trajectory control system carrier assembly on the orbiter's docking system. SpaceX took data in parallel with ''Discovery'''s Trajectory Control Sensor (TCS) system. Both the TCS and DragonEye "looked" at the [[retroreflector]]s that are on the station. After the mission, SpaceX compared the data DragonEye collected against the data collected by the TCS to evaluate DragonEye's performance.

The sensor was installed onto ''Discovery'' two weeks later than planned, following a laser rod failure during testing.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/07/sts-133-spacexs-dragoneye-late-installation-discovery/|title=STS-133: SpaceX's DragonEye set for late installation on Discovery|author=Chris Bergin|publisher=NASAspaceflight.com|date=19 July 2010|accessdate=21 July 2010}}</ref>

===Other items===
STS-133 carried the signatures of more than 500,000 students who participated in the 2010 Student Signatures in Space program, which was jointly sponsored by NASA and Lockheed Martin. The students added their signatures to posters in May 2010 as part of the annual [[Space Day]] celebration. Through their participation, students also received standards-based lessons that contained a space theme.{{Citation needed|date=February 2011}} Student Signatures in Space has been active since 1997. In that time, nearly seven million student signatures from 6,552 schools were flown on ten Space Shuttle missions.<ref name="signature">{{Cite web|url=http://www.spaceday.org/index.php/About-Sub-2.html|title=Student Signatures in Space (S3)|accessdate=8 September 2010}}</ref>

Also carried aboard ''Discovery'' were hundreds of flags, bookmarks and patches which were distributed when the shuttle returned to Earth. The mission also flew two small [[Lego]] Space Shuttles, in honor of an educational partnership between Lego and NASA. Astronauts also carried personal mementos including medallions with connections to their schools or military careers, as well as a William Shakespeare "action figure" from the English Department of the University of Texas, a stuffed giraffe mascot from the [[Memorial Hermann Healthcare System|Hermann Children's Hospital]] at the University of Texas, T-shirts from Lomax Junior High School in [[La Porte, Texas]], a blue [[Hawaiian shirt]] from NASA [[Johnson Space Center]]'s Education Office, and a shirt from a [[volunteer fire department]].<ref>{{cite web|title=STS-133: What's Going Up|url=http://www.nasa.gov/multimedia/podcasting/whatsgoingupsts133.html|work=1&nbsp;November 2010|publisher=NASA}}</ref>

==Crew==
{{Spaceflight crew
|right=yes
|terminology = Astronaut<ref name="Crew">{{Cite web|url=http://www.nasa.gov/home/hqnews/2009/sep/HQ_09-218_STS-133_Crew.html|title=NASA Assigns Crew for Final Space Shuttle Mission|accessdate=20 February 2011|publisher=NASA}}</ref><ref name="QuickLook1">{{Cite web|url=http://www.cbsnews.com/network/news/space/home/spacecalc/quicklook1.html|title=CBSNews – STS-133 Quick Look 1|accessdate=20 February 2011|publisher=CBSNews}}</ref>
|position1 = Commander
|crew1_up = [[Steven Lindsey]]
|flights1_up = Fifth and last
|position2 = Pilot
|crew2_up = [[Eric Boe]]
|flights2_up = Second
|position3 = Mission Specialist 1
|crew3_up = [[Nicole Stott]]
|flights3_up = Second and last
|position4 = Mission Specialist 2
|crew4_up = [[Alvin Drew]]
|flights4_up = Second and last
|position5 = Mission Specialist 3
|crew5_up = [[Michael Barratt (astronaut)|Michael Barratt]]
|flights5_up = Second
|position6 = Mission Specialist 4
|crew6_up = [[Stephen Bowen (astronaut)|Stephen Bowen]]
|flights6_up = Third
}}

NASA announced the STS-133 crew on 18 September 2009, and training began in October 2009. The original crew consisted of commander [[Steven Lindsey]], pilot [[Eric Boe]], and mission specialists [[Alvin Drew]], [[Timothy Kopra]], [[Michael Barratt (astronaut)|Michael Barratt]], and [[Nicole Stott]]. However, on 19 January 2011, about a month before launch, it was announced that [[Stephen Bowen (astronaut)|Stephen Bowen]] would replace original crew member Tim Kopra, after Kopra was injured in a bicycle accident.<ref name="koprareplacement">{{Cite web|url=http://www.nasaspaceflight.com/2011/01/sts-133-launch-on-track-bowen-replaces-injured-kopra/|title=STS-133 launch remains on track as Bowen replaces the injured Kopra|accessdate=19 January 2011|date=19 January 2011|publisher=nasaspaceflight.com}}</ref> All six crew members had flown at least one spaceflight before; five of the crew members, all but commander Steven Lindsey, were part of NASA's [[NASA Astronaut Group 18|Astronaut Group 18]], all being selected in the year 2000.<ref>{{cite web|url=http://www.jsc.nasa.gov/Bios/astrobio.html|title=Active Astronauts|publisher=NASA}}</ref>

The mission commander, Steven Lindsey, handed over his position as [[Chief of the Astronaut Office]] position to [[Peggy Whitson]] in order to lead the mission.<ref name=133crew /> For the first time, two mission crew members were in space when a crew assignment announcement was made, as Nicole Stott and Michael Barratt were aboard the ISS as part of the [[Expedition 20]] crew.<ref name=133crew>{{cite web|url=http://www.space.com/missionlaunches/090918-sts133-final-shuttle-crew.html|title=NASA Reveals Crew for Last Scheduled Shuttle Mission|author=Tariq Malik|publisher=SPACE.com|date=18 September 2009|accessdate=18 September 2009}}</ref> During STS-133, Alvin Drew became the last [[List of African-American astronauts|African-American]] astronaut to fly on the Space Shuttle, as no African-Americans were among the crews of [[STS-134]] and [[STS-135]]. Having flown onboard [[Space Shuttle Atlantis|''Atlantis''<nowiki>'</nowiki>]] [[STS-132]] mission, Bowen became the first and to date the only NASA astronaut to be launched on two consecutive missions.

<gallery>
File:STS-133 crew arrival.jpg|The crew pose for a photo at the KSC (including Bowen).
File:Sts133 mission poster.jpg|Mission poster (with Kopra instead of Bowen).
File:President Obama Meets With STS-133 Crew.jpg|Lindsey, far left, presents a montage to [[Barack Obama]] as crew members Barratt, Boe, Stott and Bowen look on.
</gallery>

==Mission milestones==
The mission marked:
* 164th NASA manned space flight
* 133rd shuttle mission since [[STS-1]]
* 39th flight of ''Discovery''
* 35th shuttle mission to the ISS
* 108th post-''[[Space Shuttle Challenger|Challenger]]'' mission
* 20th post-''[[Space Shuttle Columbia|Columbia]]'' mission

==Crew training==

===Terminal countdown demonstration test===
On 12 October 2010, the STS-133 crew arrived at the Kennedy Space Center to conduct the Terminal Countdown Demonstration Test (TCDT). The TCDT consisted of training for both the crew and the launch team that simulated the final hours up until launch. During the TCDT, the crew went through a number of exercises that included rescue training and a launch day simulation that included everything that would happen on launch day – except the launch. Commander Steve Lindsey and Pilot Eric Boe also performed abort landings and other flight aspects in the [[Shuttle Training Aircraft]] (STA). For the TCDT, the crew also received a briefing from NASA engineers, outlining the work that had been carried out on ''Discovery'' during the STS-133 processing flow. After successfully completing all the TCDT tasks, the crew returned to the [[Johnson Space Center]] on 15 October 2010.<ref name="vapor leak"/>

Flying aboard NASA [[Northrop T-38 Talon|T-38 training jets]], the six astronauts returned to Kennedy Space Center on 28 October 2010 for final pre-launch preparations.<ref>{{cite web|url=http://www.spaceflightnews.net/article.php?story=2010102821432056|title=All-Veteran Crew Flies To KSC For Discovery's Final Launch|author=Matthew Travis|publisher=SpaceflightNews.net|date=28 October 2010|accessdate=1 November 2010}}</ref>

<gallery class="center" >
File:STS-133 Crew Begins Dress Rehearsal.jpg|The crew gathered for the Terminal Countdown Demonstration Test.
File:Launch Pad 39A during the Terminal Countdown Demonstration Test for STS-133.jpg|[[Kennedy Space Center Launch Complex 39|Launch Pad 39A]] during the Terminal Countdown Demonstration Test.
</gallery>

On 15 January 2011, Timothy Kopra, scheduled as the lead spacewalker for the mission at the time, was injured in a bicycle accident near his Houston-area home, reportedly breaking his [[hip]].<ref name="Sub for Kopra">{{Cite web|url=http://www.usatoday.com/tech/science/space/2011-01-20-astronaut-replacement_N.htm|title=Space veteran to sub for injured astronaut|accessdate=28 January 2011|date=20 January 2011|work=USA Today}}</ref>  He was replaced by Stephen Bowen on 19 January 2011. The replacement did not affect the targeted launch date.<ref name="koprareplacement" />  This is to date the closest to a scheduled launch that a Space Shuttle crewmember has been replaced. During the [[Apollo program]], [[Jack Swigert]] replaced [[Ken Mattingly]] three days prior to the launch of [[Apollo 13]].<ref name="Sub for Kopra" />

==Shuttle processing==
STS-133 was originally manifested for launch on 16 September 2010. In June 2010 the launch date was moved to the end of October 2010 and the mission was set to take place before STS-134, which in turn had been rescheduled to February 2011. STS-133 had the longest vertical flow period (170 days) since [[STS-35]] (185 days).<ref>{{cite news|newspaper=STS-133 pre countdown news conference}}</ref>

''Discovery'' was moved from its hangar in the Orbiter Processing Facility (OPF)-3 to the nearby 52-story [[Vehicle Assembly Building]] (VAB) on 9 September 2010. The shuttle emerged from OPF-3 at 06:54 EDT and the rollover was done at 10:46 EDT when ''Discovery'' came to a rest in the VAB's transfer aisle.<ref>{{Cite web|url=http://www.collectspace.com/news/news-090910a.html|title=Space shuttle Discovery departs hangar for final flight|author=Robert Z. Pearlman|publisher=CollectSPACE|date=9 September 2010|accessdate=12 September 2010}}</ref> The quarter-mile trip between the OPF-3 and VAB was the 41st rollover for Discovery. The rollover was originally planned at 06:30 EDT on 8 September 2010. The move did not commence due to the unavailability of fire suppression systems because of a broken water main near the VAB and turn basin that runs out to the shuttle launch pads.<ref>{{cite web|url=http://content.usatoday.com/communities/sciencefair/post/2010/09/shuttle-rollover-delayed-by-water-leak/1|title=Shuttle rollover delayed by water leak|author=James Dean|publisher=Florida TODAY|date=8 September 2010|accessdate=12 September 2010}}</ref><ref>vertical flow refers to the period of time between rollout from the Shuttle Processing Facility and launch.</ref>

The two SRBs were designated as flight set 122 by contractor [[Alliant Techsystems]] and were made up from one new segment and remaining segments reused across 54 earlier shuttle missions dating back to [[STS-1]].<ref name="srb use">{{cite web|last=ATK|title=STS-133 SRB Use History|url=http://spaceflightnow.com/shuttle/sts133/fdf/133srbs.pdf|publisher=Spaceflight Now}}</ref> Inside the VAB, engineers attached a large sling to ''Discovery'' and the orbiter was rotated vertical. The orbiter was lifted into the high bay where its external tank (ET-137) and boosters were waiting to be mated. During the mating operations, an internal nut pre-positioned inside the aft compartment of the orbiter slipped out of position and fell away inside the compartment.<ref>{{Cite web|url=http://www.nasaspaceflight.com/2010/09/sts-133-engineers-repair-on-discovery-et-mate-issue/|title=STS-133: Engineers complete repair on Discovery following ET mate issue|author=Chris Bergin|publisher=NASAspaceflight.com|date=10 September 2010|accessdate=12 September 2010}}</ref> Engineers initially were worried that the orbiter would have to be removed from the ET and placed back in a horizontal orientation to make repairs. However, later they successfully accessed the area inside the aft compartment, and re-positioned the nut to complete the repairs. The bolting of the orbiter to its ET ('hard mate') was completed early in the morning of 11 September 2010 at 09:27 EDT.

The shuttle's 44th rollout to the launch pad was scheduled to begin at 20:00 EDT on 20 September 2010.<ref>{{Cite web|url=http://www.spaceflightnow.com/shuttle/sts133/100911bolt/|author=William Harwood|title=Shuttle Discovery finally bolted to external tank|publisher=Spaceflight NOW|date=11 September 2010|accessdate=12 September 2010}}</ref>  NASA sent out more than 700 invitations to shuttle workers so they could bring their families to watch Discovery's journey to the pad. However, the shuttle began the 3.4 mile trek from the VAB to the pad earlier than planned at about at 19:23 EDT on 20 September 2010.<ref>{{cite web|url=http://www.collectspace.com/news/news-092010a.html|title=Space shuttle Discovery makes last trip to launch pad|author=Robert Z. Pearlman|publisher=Collect SPACE|date=21 September 2010|accessdate=22 September 2010}}</ref> ''Discovery'' took about six hours to arrive at Pad 39A. The shuttle was secured on the launch pad by 01:49 EDT the next day.

<gallery class="center" >
File:Discovery High Bay 3 Vehicle Assembly Building STS-133.jpg|<small>''Discovery'' being lowered onto its external fuel tank and solid rocket boosters in High Bay 3 of the Vehicle Assembly Building.</small>
File:Discovery_at_Launch_Pad_(STS0133).jpg|Space Shuttle ''Discovery'' attached to Launch Pad 39A on 21 September 2010.
File:STS-133 Discovery Launch Pad 39A.jpg|Discovery at Launch Pad 39A on 1 February 2011.
File:STS 133 Discovery KSC After RSS Roll Back.jpg|Discovery is seen shortly after the [[Rotating Service Structure]] was rolled back on 23 February 2011.
</gallery>

===Orbital Maneuvering System vapor leak===
On 14 October 2010, engineers at the launch pad first discovered a small leak in a propellant line for ''Discovery''<nowiki>'</nowiki>s orbital maneuvering system (OMS) engines. The leak was detected after they noticed a fishy smell coming from the aft of the shuttle, thought of as a sign of fuel vapor in the air.<ref name="vapor leak">{{cite web|url=http://www.nasaspaceflight.com/2010/10/sts-133-tcdt-completed-troubleshooting-leaky-flight-cap/|title=STS-133: TCDT completed – Engineers troubleshooting leaky flight cap|author=Chris Bergin|publisher=NASAspaceflight.com|date=15 October 2010|accessdate=19 October 2010}}</ref> Upon inspection, the leak was found at a flange located at the interface where two propellant lines met in ''Discovery''<nowiki>'</nowiki>s aft compartment. The line carried [[monomethyl hydrazine]] (MMH) propellant, one of two chemicals (the other is an oxidizer, [[nitrogen tetroxide]]) used to ignite the OMS engines. Engineers replaced an Air Half Coupling (AHC) flight cap. However, the new cap failed to solve the problem since vapor checks still showed signs of a leak. An aspirator was activated to collect the vapor at the leak-site allowing work to continue in other locations around the aft segment of ''Discovery''.

It was believed that the leak was in the crossfeed flange area – a problem with associated seals. On 18 October 2010, after an afternoon review, engineers were asked to double-check the torque on six bolts around the suspected leaky flange fitting and tighten if necessary.<ref>{{cite web|url=http://www.spaceflightnow.com/shuttle/sts133/101018leak/|title=Technicians working on tiny fuel leak in Discovery pod
|author=William Harwood|publisher=Spaceflight Now|date=18 October 2010|accessdate=19 October 2010}}</ref> Subsequent leak tests showed again signs of seepage, and the task of solving the issue required the draining of both the left and right OMS tanks of the shuttle and a unique in-situ repair at the pad to avoid a rollback.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/10/sts-133-discovery-undergo-unique-leak-repair-avoid-rollback/|title=STS-133: Discovery to undergo unique leak repair to avoid rollback|author=Chris Bergin|publisher=NASAspaceflight.com|date=18 October 2010|accessdate=19 October 2010}}</ref> On 23 October 2010, engineers completed the removal and replacement of the two seals on the right OMS crossfeed flange, after the education (a vacuum-related procedure, used to completely clear the plumbing of the toxic MMH) of the plumbing was completed ahead of the schedule by over a day.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/10/sts-133-targeted-crossfeed-flange-seal-rr-task/|title=STS-133: Crossfeed flange seal R&R complete – OMS reload in work|date=22 October 2010|author=Chris Bergin|publisher=NASAspaceflight.com|accessdate=30 October 2010}}</ref> Later, testing indicated that the new seals were properly seated and holding pressure with no signs of additional seepage.<ref>{{cite web|url=http://www.spaceflightnow.com/shuttle/sts133/101025frr/index.html|title=Shuttle Discovery cleared for blastoff next Monday|author=William Harwood|publisher=Spaceflight Now|date=26 October 2010|accessdate=30 October 2010}}</ref> Normal pad operations commenced soon after allowing managers to press forward with the confirmation of a 1 November 2010 target launch date, with fuel reloading into the OMS tanks beginning on the morning of 24 October 2010.

===Main engine controller problem===
On 2 November, while readying ''Discovery'' for launch, engineers reported an electrical issue on the backup Main Engine Controller (MEC) mounted on Engine No. 3 (SSME-3). Earlier in the morning, engineers said that the problem had been solved, however another glitch in the system raised concerns and additional troubleshooting was ordered. Troubleshooting followed and indicated the problem was related to "transient contamination" in a circuit breaker. NASA Test Director Steve Payne, addressing reporters, told that after troubleshooting and power cycles, the controller powered up normally. However at the same time the problem was thought to be a non-issue, an unexpected voltage drop was observed.<ref>{{cite web|url=http://spaceflightnow.com/shuttle/sts133/101102mec/index.html|title=Shuttle engine controller glitch being assessed|author=William Harwood|publisher=Spaceflight Now|accessdate=20 November 2010|date=2 November 2010}}</ref>

In a Mission Management Team (MMT) meeting held later that day, managers decided to scrub the launch for at least 24 hours to work towards flight rationale.<ref>{{cite web|url=|title=STS-133: Launch delayed at least 24 hours due to Main Engine Controller issue|author=Chris Bergin|date=2 November 2010|accessdate=20 November 2010|publisher=NASApspaceflight.com}}</ref>

===Ground Umbilical Carrier Plate leak===
[[File:STS 133 GUCP Quick Disconnect removal.jpg|thumb|left|A technician begins to remove the leaky GUCP's quick disconnect.]]

On 5 November 2010, ''Discovery''<nowiki>'</nowiki>s launch attempt, a hydrogen leak was detected at the [[Ground Umbilical Carrier Plate]] (GUCP) during the fueling process. The plate was an attachment point between the external tank and a 17-inch pipe that carried gaseous hydrogen safely away from the tank to the flare stack, where it was burned off. All had been proceeding to plan with the tank "fast filled" during tanking, until the first leak indication was revealed. Firstly, a 33,000 ppm leak then reduced to a level below 20,000 ppm was recorded. The Launch Commit Criteria limit was 40–44,000 ppm. The leak was only being observed during the cycling of the vent valve to "open" to release the gaseous hydrogen from the tank to the flare stack. Controllers decided to stop valve cycling in order to increase the pressure and attempt to force a seal before attempting to complete the fast fill process. At this stage, the leak spiked and remained at the highest 60,000 ppm level (likely even at a higher value), indicating a serious problem with the GUCP's seal.

Shuttle launch director Mike Leinbach characterized the leak as "significant," similar to what was seen on [[STS-119]] and [[STS-127]], although the rate was higher in magnitude and occurred earlier in the fueling process.
[[File:STS 133 gucp replacement.jpg|thumb|160px|right|Technicians begin to install a new GUCP on the external tank.]]
After the day required to make the tank safe by purging remaining hydrogen gas with helium gas, NASA engineers prepared for disconnection of the vent arm and the significant number of lines prior to taking their first look at the GUCP. On the night of 9 November, technicians began disconnecting the GUCP by unhooking and lowering the hydrogen vent line. Teams performed an initial inspection of the flight seal and quick disconnect prior to sending them to labs for a thorough engineering analysis. Engineers reported an unevenly (asymmetrically) compressed internal seal and the quick disconnect hardware also seemed have a less concentric fit than pre-fueling measurements indicated.<ref>{{cite web|url=http://www.spaceflightnow.com/shuttle/sts133/101111leak/|title=Apparent seal problem found in leaking shuttle vent line|author=William Harwood|publisher=Spaceflight Now|date=12 November 2010|accessdate=14 November 2010}}</ref> Inspections also confirmed the condition of the hardware did not match the observations documented when it was installed on the external tank inside the VAB.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/11/sts-133-closing-in-gucp-root-cause-et-repair-pad-positive/|title=STS-133: Closing in on GUCP root cause – ET repair at pad still positive|author=Chris Bergin|publisher=NASAspaceflight.com|date=11 November 2010|accessdate=15 November 2010}}</ref>

On the morning of 12 November, teams began installing a new GUCP and completed the GUCP work over the next two days. The new plate was previously fit checked on the external tank at the [[Michoud Assembly Facility]] and yielded substantially better concentricity values than was obtained with the old and removed GUCP. Technicians took extra measurements to ensure the best possible alignment of the newly installed GUCP. Teams began installing the flight seal and quick disconnect on 15 November.

===Cracks in the external tank===
[[File:STS-133crack.jpg|120px|thumb|structural cracks in external fuel tank]]
[[File:STS-133 intertank section foam crack.jpg|left|thumb|Intertank section foam crack.]]
[[File:STS133 technicians spray foam on the tank.jpg|right|thumb|Technicians spray foam insulation on a section of repaired stringers.]]
Additional inspection of the tank revealed cracks in foam insulation in the flange between the intertank and liquid oxygen tank. The cracks are believed to have occurred about an hour after super-cold propellants began flowing into the external tank for the 5 November launch attempt. The cracks in the tank were the first to be found at the launch pad.

The insulation was cut away for additional inspection, revealing two additional 9-inch metal cracks on either side of an underlying structural rib called "stringer S-7-2". NASA managers then decided to cut away additional foam and observed two more cracks on a stringer known as S-6-2 adjacent to the two original cracks. They were found on the far left of removed foam on the flange area between the intertank and the liquid oxygen tank. However, these cracks appeared to have suffered less stress than the others found.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/11/sts-133-third-crack-found-et-137-managers-debate-plan/|author=Chris Bergin|publisher=NASAspaceflight.com|date=12 November 2010|accessdate=20 November 2010|title=STS-133: More cracks found on ET-137 as managers debate forward plan}}</ref><ref>{{cite web|url=http://spaceflightnow.com/shuttle/sts133/101115crack/|title=Fourth crack found on shuttle Discovery's external tank|author=William Harwood|date=15 November 2010|accessdate=20 November 2010|publisher=Spaceflight Now}}</ref> No cracks were found in stringers on the right side. NASA suspected the use of a lightweight aluminum-lithium alloy in the tanks contributed to the crack problem. Repairs commenced while the shuttle remained on the pad.<ref>{{cite news|title=Underlying metal cracks found on Discovery's tank|url=http://spaceflightnow.com/shuttle/sts133/101110crack/|newspaper=Spaceflight Now|accessdate=20 November 2010}}</ref>  An environmental enclosure was erected around the known damage site to facilitate the ongoing repairs and eventually to apply fresh foam insulation. On 18 November, as part of the repairs, technicians installed new sections of metal, called "doublers" because they are twice as thick as the original stringer metal providing additional strength, to replace the two cracked stringers on ''Discovery''<nowiki>'</nowiki>s external tank.

Scanning of the stringers on the liquid oxygen/intertank flange was completed on 23 November.<ref>{{cite web|url=http://www.nasaspaceflight.com/2010/11/sts-133-nasa-slip-net-december-17-target/|author=Chris Bergin and Chris Gebhardt|title=STS-133: NASA managers decide to slip to a NET December&nbsp;17 target|date=24 November 2010|accessdate=26 November 2010|publisher=NASAspaceflight.com}}</ref> NASA also performed [[backscatter]] scanning of the lower liquid hydrogen/intertank flange stringers on 29 November.

Program managers identified the analysis and repairs that were required to safely launch the shuttle, and this analysis was reviewed at a special Program Requirements Control Board (PRCB) held on 24 November. Managers announced at that meeting that the launch window available in early December would be passed up, with a new target of 17 December set, but cautioned that the launch could slip into February 2011. After reviewing the space station's December traffic model following the realigned [[Johannes Kepler ATV]]'s launch date, NASA had identified a potential launch window in mid-/late-December 2010. The 17 December 2010 date was preferred because it would have allowed the shuttle to carry more stored oxygen to the International Space Station to help it deal with oxygen generation issues, which the crew had dealt with for several months.<ref>{{cite news|title=Discovery's launch delayed until at least mid-December|url=http://www.spaceflightnow.com/shuttle/sts133/101124prcb/index2.html|newspaper=Spaceflight Now|date=24 November 2010}}</ref> "What we've told the agency leadership is that clearly we're not ready for the 3 December to 7 December window that's coming up next week," John Shannon, NASA's SSP manager, said in a news conference held after the special PCRB. "We'll leave the option open for a launch window for 17 December, but a lot of data has to come together to support that".<ref>{{cite web|url=http://www.space.com/missionlaunches/space-shuttle-discovery-new-launch-delay-101124.html|author=Denis Chow|title=Latest Launch Delay May Push Shuttle Discovery's Final Flight Into Christmas|publisher=SPACE.com|date=24 November 2010|accessdate=26 November 2010}}</ref>

===Johannes Kepler ATV rescheduled===
The launch date of 24 February 2011 was officially set after the Flight Readiness Review meeting on 18 February 2011. Reviews of previous problems, including the GUP vent line connection, external tank foam and external tank stringer cracks, were found to be positive. Additionally, flight rules which required a 72-hour separation between dockings at the International Space Station threatened to delay the launch by at least a day due to the delayed launch of the [[ESA]]'s unmanned [[Johannes Kepler ATV]] supply craft. Managers instead decided to press ahead with the countdown allowing for a possible standdown; had docking issues arisen with the ATV, STS-133 would have stood down for 48 hours.<ref>{{cite news|last=Bergin|first=Chris|title=STS-133: FRR approves Discovery's launch for next Thursday|url=http://www.nasaspaceflight.com/2011/02/sts-133-frr-approves-launch-for-next-thursday/|newspaper=Spaceflight Now|date=18 February 2011}}</ref> The Kepler ATV docked successfully at 10:59 UTC, 24 February 2011.<ref name=nasatv>[http://www.nasa.gov/multimedia/nasatv/ NASA.gov/multimedia/nasatv/: ''per NASA Live TV broadcast'']</ref>

==Launch attempts==
:''<small>All times Eastern Time, first 5 are while daylight saving time was in effect (EDT), attempt 6 is during outside of daylight saving (EST). Because of this, the final "turnaround" category should be 111 days, '''2 hours''', 49 minutes, it is not due to automatic formatting. </small>''
{{LaunchAttempt
|df=yes| date1          =  2010-11-01 16:40:00
| result1        = scrubbed<ref name="launch">{{Cite web|url=http://www.spaceflightnow.com/shuttle/sts133/101025frr/index.html|title=Shuttle Discovery cleared for blastoff next Monday|accessdate=26 October 2010|publisher=SpaceflightNow.com|author=William Harwood}}</ref>
| reason1        = technical<ref name="scrub1">[http://www.nasaspaceflight.com/2010/10/sts-133-pressurization-issues-delay-launch/ STS-133: Pressurization issues delay launch by at least a day]</ref>
| decision_date1 = 2010-10-29 10:00:00
| decision_clock1= -11 hour hold
| weathergo1     = 80%
| notes1         =OMS pod leak<ref name="scrub1" />
| date2          = 2010-11-02 16:18:00
| result2        = scrubbed<ref name="nov3launch">{{cite web|title=Countdown to Start Sunday for Targeted Launch Wednesday|url=http://www.nasa.gov/mission_pages/shuttle/main/index.html|publisher=NASA|accessdate=30 October 2010}}</ref>
| reason2        = technical<ref name="nov3launch"/>
| decision_date2 = 
| decision_clock2= -11 hour hold
| weathergo2     = 70%
| notes2         =OMS pod leak<ref name="nov3launch"/>
| date3 = 2010-11-03 15:52:00
| result3 = scrubbed<ref name=scrub3>{{cite news|title=Shuttle Wont Launch Wednesday|url=http://www.chicagotribune.com/news/nationworld/os-nasa-discovery-problem-20101102,0,6911346.story|accessdate=2 November 2010|newspaper=Chicago Tribune|date=2 November 2010}}</ref>
| reason3 = technical<ref name=scrub3/>
| decision_date3 = 2010-11-02 05:40:00
| decision_clock3 =-11 built-in hold
| weathergo3 = 70%
| notes3 = Electrical fault in backup [[SSME]] controller.
| date4 = 2010-11-04 15:29:54 EDT
| result4 = scrubbed<ref name="SFN 133">{{cite web|title=STS-133 coverage|url=http://www.spaceflightnow.com/shuttle/sts133/status.html|publisher=Spaceflight now}}</ref>
| reason4 = weather<ref name=scrub4>{{cite web|title=Discover scrubbed|url=http://www.nasaspaceflight.com/2010/11/sts-133-live-attempt-one/|publisher=Spaceflight.com}}</ref><ref>[http://www.spaceflightnews.net/article.php?story=20101103114052888 Electrical Issue Delays Discovery Launch Another 24 Hours]</ref>
| decision_date4 = 4 November 2010 06:25:00
| decision_clock4 =
| weathergo4 = 20%
| notes4 = Decision made at pre-tanking weather briefing to reset clock to T-11 hold and delay ~24 hours due to rainy conditions.<ref name=scrub4/><ref>[http://www.spaceflightnews.net/article.php?story=20101105171014399 Weather Forces Another Delay For Discovery Launch]</ref>
| date5 = 2010-11-05 15:04:01
| result5 = scrubbed
| reason5 = technical
| decision_date5 =2010-11-05 12:00:00
| decision_clock5 = -6 hold
| weathergo5 = 60%
| notes5 = Hydrogen leak detected at [[ground umbilical carrier plate]] (GUCP)<ref>[http://www.spaceflightnews.net/article.php?story=2010110617285597 Hydrogen Leak Forces Scrub Of Discovery Launch]</ref>
| date6 =  2011-02-24 16:53:24
| result6 = success
| reason6 =
| decision_date6 =
| decision_clock6 =
| weathergo6 = 90%
| notes6 = The clock was held at T-5 minutes to allow time to resolve a computer issue at the [[Range Safety Officer]]'s console. The issue was resolved and the clock restarted in time to allow ''Discovery'' to launch with just two seconds left in the [[launch window]].<ref>[http://spaceflightnow.com/shuttle/sts133/fdf/133count.html STS-133 countdown]</ref><ref>{{cite news|title=STS-133 Launches on Historic Final Mission for Shuttle Discovery|url=http://www.universetoday.com/83529/sts-133-launches-on-historic-final-mission-for-shuttle-discovery/comment-page-1/|date=24 February 2011}}</ref>
}}

==Mission timeline==
:'' Section source: NASA Press Kit''<ref>[http://www.nasa.gov/pdf/491387main_STS-133%20Press%20Kit.pdf NASA Official STS-133 Press Kit]</ref> and NASA TV Live<ref name=nasalive/> The original nominal mission of twelve days was eventually extended by two days, one at a time.

===24 February (Flight Day 1 – Launch)===
Space Shuttle ''Discovery'' successfully lifted off from [[Kennedy Space Center]]'s [[Kennedy Space Center Launch Complex 39|Launch Pad 39A]] at 16:53:24 EST on 24 February 2011. Liftoff was initially set for 16:50:24, but was delayed for 3 minutes by a minor glitch in a computer system used by the [[Range Safety Officer]] (RSO) for the [[Eastern Range]]. Once ''Discovery'' was cleared for launch, it took 8 minutes and 34 seconds to reach orbit. At approximately four minutes into flight, a piece of foam was seen breaking away from the External Tank. This foam was deemed not to be a threat, since it was liberated after the shuttle had left Earth's atmosphere. During ''Discovery''<nowiki>'</nowiki>s ascent, NASA managers also reported that they saw three more additional instances of foam liberation.<ref>{{cite web|url=|title=http://www.collectspace.com/flightdayjournal/sts-133/02.html|publisher=CollectSPACE|date=25 February 2011|accessdate=26 February 2011}}</ref> These losses also occurred after aerodynamic sensitive times when debris could seriously damage the shuttle, and so were deemed non-threatening. NASA's engineers accounted the foam losses to a condition called "cryo-pumping". When the external tank is loaded with liquid hydrogen, the air trapped in the foam first liquifies. During the ride into orbit, as the hydrogen level in the tank drops, it warms up and the liquefied air turns back into a gas. The pressure generated due to the state change of hydrogen can cause parts of foam in the tank to come off.<ref>{{cite web|url=http://spaceflightnow.com/shuttle/sts133/110225fd2/index3.html|title='Cryopumping' likely cause of Discovery tank foam loss|date=25 February 2011|accessdate=26 February 2011|author=William Harwood|publisher=Spaceflight Now}}</ref>

Once on orbit, the crew of STS-133 opened the payload bay doors and activated the K<sub>u</sub> band antenna for high-speed communications with Mission Control. While the K<sub>u</sub> band antenna was being activated, Alvin Drew and Pilot Eric Boe activated the Shuttle Remote Manipulator System (SRMS), also known as the [[Canadarm]]. Later in the day, imagery of the External Tank during launch was downlinked for analysis.<ref name="NSFFD1">{{Cite web|url=http://www.nasaspaceflight.com/2011/02/live-discovery-into-tanking-operations-for-sts-133-launch-attempt/|title=Discovery launches after dramatic range fix late in countdown|accessdate=25 February 2011|publisher=NASASpaceflight.com|author=Chris Bergin & Chris Gebhardt}}</ref>

<gallery class="center">>
File:STS-133 launch.jpg|Space Shuttle ''Discovery'' rockets into orbit for the final time, 24 February 2011.
File:STS-133 launch video.ogv|'''STS-133 launch video''' (2 mins 32 secs).
File:STS-133 Discovery Lift Off Launch Pad 39A KSC.jpg|''Discovery'' lifts off from Launch Pad 39A.
File:STS133 launch.jpg|Close up of the launch from Pad 39A.
</gallery>

===25 February (Flight Day 2 – OBSS inspection)===
Flight Day 2 saw the crew of ''Discovery'' begin their preparations to dock with the [[International Space Station]] (ISS). The day started with a firing of the [[Orbital Maneuvering System]] (OMS) engine, called the NC2 burn, to help ''Discovery'' catch up to the ISS. Commander Steve Lindsey, Pilot Eric Boe and Mission Specialist Al Drew began the day performing an inspection of the Re-enforced Carbon-Carbon (RCC) panels with the [[Orbital Boom Sensor System]] (OBSS). Lindsey and Boe started the inspection on the starboard wing and nose cap, and continued on with the port wing; the whole survey took about six hours to complete. Drew joined up with Michael Barratt and Steve Bowen to checkout and get their two [[Extravehicular Mobility Unit]]s (EMUs) ready for the two spacewalks that would be conducted during the mission. Later in the day, the crew checked out the rendezvous tools to ensure they were operational. At the end of the day, another OMS engine firing, known as the NC3 burn, took place.<ref name="NSFFD02">{{Cite web|url=http://www.nasaspaceflight.com/2011/02/sts-133-healthy-discovery-fd2-inspections-rcc-panels/|title=STS-133 – Healthy Discovery completes FD2 inspections on RCC panels|accessdate=26 February 2011|publisher=NASASpaceflight.com|author=Chris Bergin}}</ref>

===26 February (Flight Day 3 – ISS rendezvous)===
The orbiter docked to the ISS on Flight Day 3, marking the 13th time ''Discovery'' had visited the ISS. The docking occurred on time at 19:14 UTC. A hard mate between the two vehicles was delayed by about 40 minutes because of relative motion between the station and shuttle, thus putting the crew behind the timeline for the day. The hatches were finally opened at 21:16 UTC, and the [[Expedition 26]] crew greeted the crew of STS-133.<ref name="mccstat5">{{Cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/news/STS-133-05.html|title=STS-133 MCC Status Report No. 05 |accessdate=27 February 2011|publisher=NASA}}</ref> After the welcome ceremony and safety briefing, the crew's main task of the day was to transfer the [[ExPRESS Logistics Carrier]] 4 (ELC-4). ELC-4 was taken out of ''Discovery's'' payload bay by the Space Station Remote Manipulator (SSRMS), also known as [[Canadarm2]], which was operated by Nicole Stott and Michael Barratt. The SSRMS handed it to the Shuttle Remote Manipulator System (SRMS), which was being controlled by Boe and Drew, while the SSRMS moved to the Mobile Base System (MBS). Once there, the SSRMS took ELC-4 back from the SRMS, and installed it at its location on the [[Integrated Truss Structure|S3 truss]] location. ELC-4 was installed in its final location at 03:22 UTC on 27 February.<ref name="sfnfd3">{{Cite web|url=http://www.spaceflightnow.com/shuttle/sts133/110226fd3/index2.html|title=Discovery pulls into port for her final space station visit|accessdate=27 February 2011|publisher=CBS News|author=Bill Harwood}}</ref> While the robotic transfer was going on, Bowen and Lindsey were transferring items that were needed for Flight Day 4 and the spacewalk on Flight Day 5.

<gallery class="center">>
File:STS-133 Discovery Nose Forward Underside & Crew Cabin.jpg|View of the nose, the forward underside and crew cabin of ''Discovery'' during the [[Rendezvous Pitch Maneuver]].
File:STS-133 Rendezvous Pitch Maneuver 2.jpg|View of the aft portion of ''Discovery''<nowiki>'</nowiki>s main engines, part of the payload bay, vertical stabilizer and Orbital Maneuvering System pods during the RPM.
File:Discovery Backflip.ogg|Video of the RPM.
File:STS-133 docked to ISS.jpg|''Discovery'' shortly after docking with the International Space Station on 26 February 2011.
File:STS-133 Discovery seen from the Cupola.jpg|The docked ''Discovery'' and Dextre are featured in this photograph.
</gallery>

===27 February (Flight Day 4)===
On Flight Day 4, Stott and Barratt grappled the [[Orbiter Boom Sensor System]] (OBSS) using the Canadarm2 and removed it from the starboard sill of ''Discovery's'' payload bay. Once it was grappled and out of the payload bay, the Shuttle Remote Manipulator System grappled the end of the OBSS and took a hand off from the Canadarm2. The OBSS was grappled by the space station arm, because the SRMS could not reach it due to clearance issues, and it needed to be moved out of the way so that the [[Permanent Multipurpose Module]] (PMM) could be removed from the payload bay. After the OBSS hand off, the entire STS-133 crew was joined by ISS [[Expedition 26]] commander [[Scott Kelly (astronaut)|Scott Kelly]] and flight engineer [[Paolo Nespoli]] for a series of in-flight media interviews. The interviews were conducted with the [[Weather Channel]], [[WBZ (AM)|WBZ]] radio in Boston, Massachusetts, [[WSB-TV]] in Atlanta, Georgia, and [[WBTV]] in Charlotte, North Carolina.<ref name="mccstat7">{{Cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/news/STS-133-07.html|title=STS-133 MCC Status Report No. 07 |accessdate=28 February 2011|publisher=NASA}}</ref> The crew also completed more cargo transfers to and from the ISS. Throughout the day, Drew and Bowen prepared tools that they would use on their spacewalk on Flight Day 5. Later in the day, they were joined by the shuttle crew and ISS commander Kelly and Flight Engineer Nespoli, for a review of the spacewalk procedures. After the review, Bowen and Drew donned oxygen masks and entered the crew lock of the [[Quest airlock]] for the standard pre-spacewalk campout. The airlock was lowered to 10.2 psi for the night. This was done to help the spacewalkers purge nitrogen from their blood and help prevent [[decompression sickness]], also known as the bends.<ref name="sfnfd4">{{Cite web|url=http://www.spaceflightnow.com/shuttle/sts133/110227fd4/index2.html|title=Astronauts having on busy Sunday aboard the station|accessdate=28 February 2011|publisher=CBS News/SpaceflightNow|author=Bill Harwood}}</ref>

===28 February (Flight Day 5 – EVA 1)===
Steve Bowen and Alvin Drew performed the mission's first [[extra-vehicular activity]] (EVA), or spacewalk, on Flight Day 5. After waking up at 6:23&nbsp;am EST, the crew immediately began EVA preparations.<ref name=eva1>{{cite web|last=Gebhardt|first=Chris|title=STS-133: EVA-1 completed; Endeavour Rolls to VAB one last time|url=http://www.nasaspaceflight.com/2011/02/discovery-eva-1-endeavour-rolls-vab-last-time/|publisher=nasaspaceflight.com|accessdate=7 March 2011}}</ref> A conference was held between the crew of the station and Mission Control at about 8:20&nbsp;am, followed by further EVA preparation work, including the depressurization of the airlock. Bowen and Drew switched their spacesuits to internal battery power at 10:46&nbsp;am, marking the beginning of EVA 1.<ref name=eva1/>

During the EVA, Bowen and Drew installed a power cable linking the ''Unity'' and ''Tranquility'' modules in order to provide a contingency power source, should it become required. They then moved a failed ammonia pump, which was replaced in August 2010, from its temporary location to the [[External Stowage Platform|External Stowage Platform 2]]. Later, operations with the SSRMS robotic arm were delayed to due technical problems with the robotic control station in the ''Cupola'' module.<ref name=eva1/>

After installing a wedge under a camera on the [[Integrated Truss Structure|S3 truss]] to provide clearance from the newly installed [[ExPRESS Logistics Carrier]]-2, performing a Japanese experiment called ''Message in a Bottle'' to collect a sample of vacuum, and other minor tasks, the EVA ended after six hours and 34 minutes at 5:20&nbsp;pm EST.

<gallery class="center" >
File:STS-133 Bowen & Drew Spacewalk.jpg|Bowen & Drew (partially obscured at centre) during EVA 1.
File:STS-133 Bowen & Drew EVA 1.jpg|Bowen & Drew during EVA 1.
</gallery>

===1 March (Flight Day 6 – PMM installation)===

Flight Day 6 saw the installation of the ''Leonardo'' Permanent Multipurpose Module (PMM) to the nadir, or Earth-facing, port of the station's ''Unity'' module. Once the installation was complete, the external outfitting of ''Leonardo'', to integrate it into the ISS as a permanent module, was begun. Bowen and Drew conducted the procedure review for the mission's second spacewalk, before beginning their pre-EVA campout in the Quest airlock.

===2 March (Flight Day 7 – EVA 2)===

Bowen and Drew conducted STS-133's second EVA on Flight Day 7. Drew removed thermal insulation from a platform, while Bowen swapped out an attachment bracket on the ''Columbus'' module. Bowen then installed a camera assembly on the [[Dextre]] robot and removed insulation from Dextre's electronics platform. Drew installed a light on a cargo cart and repaired some dislodged thermal insulation from a valve on the truss. Meanwhile, the ISS and shuttle crew entered the ''Leonardo'' PMM to commence the internal outfitting of the module.

===3 March (Flight Day 8)===

On Flight Day 8, the transfer of the ''Leonardo'' PMM's cargo to the interior of the ISS began. The crew also received some off-duty time on this day.

===4 March (Flight Day 9)===

On Flight Day 9, the equipment used on Drew and Bowen's spacewalk was reconfigured. A joint crew news conference was also conducted via satellite, after which the crew received more off-duty time.

===5 March (Flight Day 10)===

The internal outfitting of the ''Leonardo'' PMM continued on Flight Day 10.<ref name="mission extension">{{cite news|last=Harwood|first=William|title=Mission extended one day|url=http://www.spaceflightnow.com/shuttle/sts133/110228fd5/index6.html|accessdate=1 March 2011|newspaper=CBS News|date=28 February 2011}}</ref>
Furthermore, a photo shoot of the ISS with multiple spacecraft docked was considered, but rejected by mission planners.<ref name="mission extension"/><ref name=photoopcancel>{{cite news|last=Harwood|first=William|title=Proposed Ultimate Space Station Photo Op Rejected|url=http://spaceflightnow.com/shuttle/sts133/110301fd6/index2.html|accessdate=1 March 2011|date=1 March 2011}}</ref>

===6 March (Flight Day 11)===

As well as the continued outfitting of the ''Leonardo'' Permanent Multipurpose Module,<ref name="mission extension"/>
a checkout of ''Discovery''<nowiki>'</nowiki>s rendezvous tools was conducted on Flight Day 11, before the shuttle crew said their farewells to the ISS crew, exited the station and sealed the hatch between the orbiter and the ISS. The installation of a center-line camera was also conducted on this day.

===7 March (Flight Day 12 – Undocking)===

''Discovery'' conducted its final undocking from the ISS on Flight Day 12, and its last fly-around preceded the final separation from the station. A late inspection of ''Discovery'''s [[Thermal Protection System]] was conducted using the [[Orbiter Boom Sensor System|OBSS]], before the OBSS was berthed.

===8 March (Flight Day 13)===

The crew of ''Discovery'' stowed their equipment in the sle's cabin before conducting a checkout of the flight control system and a hot-fire test of the [[reaction control system]]. A final deorbit preparation briefing was carried out before the shuttle's K<sub>u</sub> band antenna was stowed.

===9 March (Flight Day 14 – Re-entry and landing)===

On the final day of the mission, ''Discovery''<nowiki>'</nowiki>s crew carried out further deorbit preparations, and closed the shuttle's payload bay doors. A successful deorbit burn and re-entry ended with ''Discovery'' landing at [[Kennedy Space Center]]'s [[Shuttle Landing Facility]] for the final time on 9 March 2011 at 11:58:14 EST. The shuttle was retired at wheel-stop.

<gallery class="center">>
File:Concluding the STS-133 mission, Space Shuttle Discovery touches down at the Shuttle Landing Facility.jpg|Space Shuttle ''Discovery'' lands for the final time, at the [[Shuttle Landing Facility]] on 9 March 2011.
File:STS-133 landing.ogg|Video recording of the STS-133 landing.<br />(2 mins 30 secs)
</gallery>

==Spacewalks==
Two spacewalks (EVAs) were conducted during the mission.<ref name="STS 133 duration and eva">{{cite web|url=http://www.nasaspaceflight.com/2010/06/sts-133-three-flight-days-and-two-evas-added-to-discoverys-mission/|title=STS-133: Three Flight Days and two EVAs added to Discovery's mission|author=Chris Gebhardt|publisher=NASAspaceflight.com|date=11 June 2010|accessdate=11 June 2010}}</ref>

{| class="wikitable"
|-
! style="width: 5em;" | EVA
! Spacewalkers
! Start (UTC)
! End (UTC)
! Duration
|-
| rowspan="2" | EVA 1
| [[Stephen G. Bowen|Steve Bowen]] <br> [[Benjamin Alvin Drew|Alvin Drew]]
| 28 February 2011 <br> 15:46
| 28 February 2011 <br> 22:20
| 6 hours 34 minutes
|-
| colspan="4" | Drew and Bowen installed a power extension cable between the Unity and Tranquility nodes to provide a contingency power source should it be required. The spacewalkers then moved the failed ammonia pump module that was replaced in August from its temporary location to the [[External Stowage Platform|External Stowage Platform 2]] adjacent to the [[Quest airlock]]. Drew and Bowen then installed a wedge under a camera on the [[Integrated Truss Structure|S3 truss]] to provide clearance from the newly installed ELC-4. They next replaced a guide for the rail cart system used for moving the station robotic arm along the truss. The guides had been removed when astronauts were performing work on the station's starboard [[Solar Alpha Rotary Joint]] (SARJ), which rotates the solar arrays to track the sun. The final task was to "fill" a special bottle with the vacuum of space for a Japanese education payload. The bottle will be part of a public museum exhibit.
|-
| rowspan="2" | EVA 2
| Steve Bowen <br> Alvin Drew
| 2 March 2011 <br> 15:42
| 2 March 2011 <br> 21:56
| 6 hours 14 minutes
|-
| colspan="4" | Drew removed thermal insulation from a platform, while Bowen swapped out an attachment bracket on the [[Columbus (ISS module)|''Columbus'' module]]. Bowen then installed a camera assembly on the [[Dextre]] robot and removed insulation from Dextre's electronics platform. Drew installed a light on a cargo cart and repaired some dislodged thermal insulation from a valve on the truss.
|}

==Wake-up calls==
NASA began a tradition of playing music to astronauts during the [[Gemini program]], and first used music to wake up a flight crew during [[Apollo 15]].
Each track is specially chosen, often by the astronauts' families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.<ref name="chronology">{{cite news|title=Chronology of Wakeup Calls| date=2 August 2005|publisher=NASA|url=http://history.nasa.gov/wakeup.htm|accessdate=5 April 2010}}</ref><ref name="wakeup">{{Cite web|url=http://spaceflight1.nasa.gov/gallery/audio/shuttle/sts-133/html/ndxpage1.html|title=STS-133 Wakeup Calls|publisher=[[NASA]]|date=November 2010}}</ref>

NASA opened the selection process to the public for the first time for STS-133. The public was invited to vote on two songs used to wake up astronauts on previous missions to wake up the STS-133 crew.<ref>{{cite web|title=NASA's Space Rock|url=https://songcontest.nasa.gov|publisher=NASA}}</ref>

{| class="wikitable"
|-
! Flight Day
! Song
! Artist
! Played for
! Links
|-
| Day 2
| "[[The Prince of Egypt (soundtrack)|Through Heaven's Eyes]]"
| [[Brian Stokes Mitchell]]
| [[Michael R. Barratt]]
| [http://www.archive.org/download/STS-133/02-25-11_sts-133_fd2_crewWakeup.wav WAV], [http://www.archive.org/download/STS-133/2-25-11_STS-133_FD2_Crew_Wakeup-01.mp3 MP3]
|-
| Day 3
| "[[Woody's Roundup]]"
| [[Riders in the Sky (band)|Riders in the Sky]]
| [[B. Alvin Drew|Alvin Drew]]
| [http://spaceflight1.nasa.gov/gallery/audio/shuttle/sts-133/wave/fd03.wav WAV], [http://www.archive.org/download/STS-133/2-26-11_STS-133_FD3_Crew_Wakeup-01.mp3 MP3]
|-
| Day 4
| "Java Jive"
| [[The Manhattan Transfer]]
| [[Steven Lindsey]]
| [http://www.archive.org/download/STS-133/02-27-11_STS-133_FD4_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/2-27-11_STS-133_FD4_Crew_Wakeup-01.mp3 MP3]
|-
| Day 5
| "[[Oh What a Beautiful Morning]]"
| [[Davy Knowles]] & [[Back Door Slam]]
| [[Nicole Stott]]
| [http://www.archive.org/download/STS-133/02-28-11_STS-133_FD5_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/02-28-11_STS-133_FD5_Crew_Wakeup-01.mp3 MP3]
|-
| Day 6
| "[[Happy Together (song)|Happy Together]]"
| [[The Turtles]]
| [[Stephen Bowen (astronaut)|Stephen Bowen]]
| [http://www.archive.org/download/STS-133/03-01-11_STS-133_FD6_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-01-11_STS-133_FD6_Crew_Wakeup-01.mp3 MP3]
|-
| Day 7
| "[[Speed of Sound (song)|The Speed of Sound]]"
| [[Coldplay]]
| [[Eric Boe]]
| [http://www.archive.org/download/STS-133/03-02-11_STS-133_FD7_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-02-11_STS-133_FD7_Crew_Wakeup-01.mp3 MP3]
|-
| Day 8
| "[[City of Blinding Lights]]"
| [[U2]]
| [[STS-133#Crew|STS-133 Crew]]
| [http://ia700406.us.archive.org/13/items/STS-133/03-03-11_STS-133_FD8_Crew_Wakeup.wav WAV], [http://ia700406.us.archive.org/13/items/STS-133/03-03-11_STS-133_FD8_Crew_Wakeup-01.mp3 MP3]
|-
| Day 9
| "The Ritual/Ancient Battle/2nd Kroykah"
| [[Gerald Fried]] - ''(Composer)''
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-04-11_STS-133_FD9_Crew_wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-04-11_STS-133_FD9_Crew_wakeup.mp3 MP3]
|-
| Day 10
| "[[Ohio (Come Back to Texas)]]"
| [[Bowling for Soup]]
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-05-11_STS-133_FD10_Crew_wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-05-11_STS-133_FD10_Crew_wakeup.mp3 MP3]
|-
| Day 11
| "Spaceship Superstar"
| [[Prism (band)|Prism]]
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-06-11_STS-133_FD11_Crew_wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-06-11_STS-133_FD11_Crew_wakeup.mp3 MP3]
|-
| Day 12
| Theme to "[[Star Trek]]"
| Voice-over by [[William Shatner]] <br/> Song by [[Alexander Courage]]
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-07-11_STS-133_FD12_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-07-11_STS-133_FD12_Crew_Wakeup.mp3 MP3]
|-
| Day 13
|"Blue Sky" (Live)
| [[Big Head Todd and the Monsters]]
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-08-11_STS-133_FD13_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-08-11_STS-133_FD13_Crew_Wakeup.mp3 MP3]
|-
| Day 14
| "Coming Home"
| [[Gwyneth Paltrow]]
| STS-133 Crew
| [http://www.archive.org/download/STS-133/03-09-11_STS-133_FD14_Crew_Wakeup.wav WAV], [http://www.archive.org/download/STS-133/03-09-11_STS-133_FD14_Crew_Wakeup.mp3 MP3]
|}

==See also==
* [[2011 in spaceflight]]
* [[List of human spaceflights]]
* [[List of International Space Station spacewalks]]
* [[List of Space Shuttle missions]]
* [[List of spacewalks 2000—2014]]
* [[Space Shuttle Discovery|Space Shuttle ''Discovery'']]

==References==
{{Include-NASA}}
{{Reflist|30em}}

==External links==
{{Commons}}

*[http://www.nasa.gov/mission_pages/shuttle/main/index.html NASA's space shuttle page]
*[http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/index.html NASA's STS-133 mission page]
*[http://www.icarelive.com/news/news.php?cat_id=1&article_id=16854 Watch STS-133 launch video] / ICARE Live
*[http://twitter.com/search?q=%23sts133 Twitter Feed of the events for sts-133]
*[http://www.collectspace.com/flightdayjournal/sts-133/ STS-133 Flight Day Journal] – [[collectSPACE]]
*[http://www.spaceflightnews.net/staticpages/index.php?page=sts133-preflight-brf STS-133 Preflight Briefings Video] – [http://www.spaceflightnews.net SpaceflightNews.net] / NASA TV
*[http://www.spaceflightnews.net/staticpages/index.php?page=bts-astro-mike Behind the Scenes With Astronaut Mike Massimino] – [http://www.spaceflightnews.net SpaceflightNews.net] / NASA TV
*[http://www.spaceflightnews.net/staticpages/index.php?page=sts133-interviews STS-133 preflight crew interview videos] – SpaceflightNews.net / NASA TV
*[http://legault.perso.sfr.fr/STS-133.html 3D video of ISS and STS-133], from Thierry Legault as observed from the Earth's surface
*[http://www.bbc.co.uk/news/science-environment-13941347 Space Shuttle Discovery STS-133 Astronauts Interviewed for BBC Breakfast] / BBC TV
*[http://www.youtube.com/watch?v=xk-GvkhKE5c Video: STS-133 Space Shuttle Crew Ready For Discovery's Final Mission Part 1] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=puve-xZGJ4g Video: STS-133 Space Shuttle Crew Ready For Discovery's Final Mission Part 2] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=yIiIAjzvUfI Video: STS-133 – Terminal Countdown Demonstration Test Crew Q & A Session at Launch Pad 39A Part 1] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=9cWufy31rII Video: STS-133 – Terminal Countdown Demonstration Test Crew Q & A Session at Launch Pad 39A Part 2] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=wyCNW2qLFYs Video: STS-133 Discovery astronauts take part in countdown dress rehearsal Part 1] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=QLxQW-ELDX0 Video: STS-133 Discovery astronauts take part in countdown dress rehearsal Part 2] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=yZW3niZU6no Video: STS-133 Crew Arrives For Shuttle Terminal Countdown Demonstration Test] – SpaceflightNews.net / YouTube
*[http://www.youtube.com/watch?v=GE_USPTmYXM Video: STS-133 Launch Seen From Airplane] – STS-133 launch seen from airplane / YouTube
*[http://nasatech.net/nasatechSTS-133_MISSION_PAGE.html nasatech.net STS-133 Mission Page with spherical panoramas on the pad, in the VAB and the payload in the SSPF]

{{Space Shuttle Discovery}}
{{Manned ISS flight}}

{{DEFAULTSORT:Sts-133}}
[[Category:Space Shuttle missions]]
[[Category:Spacecraft launched in 2011]]
[[Category:Spacecraft which reentered in 2011]]
[[Category:Articles containing video clips]]