View source for STS-91

{{Short description|Final Space Shuttle mission to the Mir space station}}
{{Use dmy dates|date=October 2019}}
{{Infobox spaceflight
| name               = STS-91
| names_list         = [[Space Transportation System]]-91
| image              = STS-91 Landing.jpg
| image_caption      = ''Discovery'' lands at Kennedy, concluding the last mission in the Shuttle–''Mir'' program
| insignia           = Sts-91-patch.png
| spacecraft         = {{OV|103}}
| mission_type       = [[Shuttle-Mir program|Shuttle-Mir]]
| operator           = [[NASA]]
| COSPAR_ID          = 1998-034A
| SATCAT             = 25356
| orbits_completed   =
| distance_travelled =
| mission_duration   = 9&nbsp;days, 19&nbsp;hours, 54&nbsp;minutes, 2&nbsp;seconds
| launch_mass        =
| landing_mass       = {{convert|117861|kg}}
| payload_mass       = {{convert|16537|kg}}
| launch_site        = [[Kennedy Space Center|Kennedy]], [[Kennedy Space Center Launch Complex 39A|LC-39A]]
| launch_date        = {{start-date|2 June 1998, 22:06:24|timezone=yes}}&nbsp;UTC
| landing_date       = {{end-date|12 June 1998, 18:00:18|timezone=yes}}&nbsp;UTC
| landing_site       = Kennedy, [[Shuttle Landing Facility|SLF&nbsp;Runway&nbsp;15]]
| crew_size          = 6 up<br/>7 down
| crew_members       = {{Unbulleted list|[[Charles J. Precourt]]|[[Dominic L. Pudwill Gorie]]|[[Franklin R. Chang-Diaz]]|[[Wendy B. Lawrence]]|[[Janet L. Kavandi]]|[[Valery Ryumin]]}}
| crew_landing       = {{Unbulleted list|[[Andrew S. W. Thomas]]}}
| crew_photo         = STS-91_crew.jpg
| crew_photo_caption = Left to right – Front: Gorie, Precourt; Back: Lawrence, Chang-Diaz, Kavandi, Ryumin, Thomas
| docking            = {{Infobox spaceflight/Dock
|docking_target      = [[Mir]]
|docking_type        = dock
|docking_port        = [[Mir Docking Module|SO]]&nbsp;starboard
|docking_date        = 4 June 1998, 16:58&nbsp;UTC
|undocking_date      = 8 June 1998, 16:01&nbsp;UTC
|time_docked         = 3&nbsp;days, 23&nbsp;hours, 3&nbsp;minutes
}}
| apsis              = gee
| orbit_epoch        =
| orbit_reference    = [[geocentric orbit|Geocentric]]
| orbit_regime       = [[Low Earth orbit|Low Earth]]
| orbit_periapsis    = {{convert|350|km}}
| orbit_apoapsis     = {{convert|373|km}}
| orbit_period       = 91.8 min
| orbit_inclination  = 51.7 degrees
| programme          = [[Space Shuttle program]]
| previous_mission   = [[STS-90]] (90)
| next_mission       = [[STS-95]] (92)
}}
'''STS-91''' was the 24th flight of Discovery, and the final [[Space Shuttle]] mission to the ''[[Mir]]'' space station. It was flown by [[Space Shuttle Discovery|Space Shuttle ''Discovery'']], and launched from [[Kennedy Space Center]], Florida, on 2 June 1998.<ref>{{cite news |last1=Suriano |first1=Robyn |title=Final Flight to Mir Begins |url=https://www.newspapers.com/clip/103307198/ |access-date=7 June 2022 |work=Florida Today |date=June 3, 1998 |page=1}}</ref>
==Crew==
{{Spaceflight crew
|terminology       = Astronaut
|position1         = Commander
|crew1_up          = {{flagicon|USA}} [[Charles J. Precourt]]
|flights1_up       = Fourth and last
|position2         = Pilot
|crew2_up          = {{flagicon|USA}} [[Dominic L. Pudwill Gorie]]
|flights2_up       = First
|position3         = Mission Specialist 1
|crew3_up          = {{Flagicon|USA}}/{{Flagicon|CRC}}<!-- Chang-Díaz wore the US flag on his arm, so it should be listed first --> [[Franklin Chang-Díaz]]
|flights3_up       = Sixth
|position4         = Mission Specialist 2<br>Flight Engineer
|crew4_up          = {{flagicon|USA}} [[Wendy B. Lawrence]]
|flights4_up       = Third
|position5         = Mission Specialist 3
|crew5_up          = {{flagicon|USA}} [[Janet L. Kavandi]]
|flights5_up       = First
|position6         = Mission Specialist 4
|crew6_up          = {{flagicon|RUS}} [[Valery Ryumin]]
|flights6_up       = Fourth and last
|agency6_up        = [[Russian Federal Space Agency|RKA]]
|position7         = Mission Specialist 5
|crew7_up          = None
|crew7_down        = {{flagicon|USA}}/{{flagicon|AUS}}<!-- Thomas wore the US flag on his arm, so it should be listed first --> [[Andy Thomas]]
|flights7_down     = Second
|expedition7_down  = [[Mir EO-25|EO-25]]
}}
=== Crew seat assignments ===
{| class="wikitable" style="text-align:center"
! Seat<ref name="spacefacts">{{Cite web |title=STS-91 |url=http://spacefacts.de/mission/english/sts-91.htm |url-status=live |archive-url=https://web.archive.org/web/20180520023309/http://www.spacefacts.de/mission/english/sts-80.htm |archive-date=May 20, 2018 |access-date=January 3, 2018 |publisher=Spacefacts}}</ref>
! Launch
! Landing
|rowspan=8| [[File:Space Shuttle seating plan.svg|150px]]<br />Seats 1–4 are on the flight deck.<br />Seats 5–7 are on the mid-deck.
|-
! 1
|colspan=2| Precourt
|-
! 2
|colspan=2| Gorie
|-
! 3
|Chang-Diaz
|Kavandi
|-
! 4
|colspan=2| Lawrence
|-
! 5
|Kavandi
|Chang-Diaz
|-
! 6
|colspan=2| Ryumin
|-
! 7
| -
|Thomas
|}
==Mission highlights==
STS-91 marked the final Shuttle/''Mir'' Docking Mission, as well as the only such docking for ''Discovery''. This [[Shuttle–Mir Program|Phase 1 Program]] was a precursor to the [[International Space Station]] maintaining a continuous American presence in space and developing the procedures and hardware required for an international partnership in space.
The mission was the first to use the super lightweight external tank ([[Space Shuttle external tank|SLWT]]) which was the same size, at {{convert|154|ft|m}} long and {{convert|27|ft|m}} in diameter, as the external tank used on previous launches, but {{convert|7500|lb|kg}} lighter. The tank was made of an aluminium lithium alloy and the tank's structural design had also been improved making it 30 percent stronger and 5 percent less dense. The walls of the redesigned hydrogen tank were machined in an orthogonal waffle-like pattern, providing more strength and stability than the previous design. These improvements would later provide additional payload capacity to the International Space Station.
Docking of ''Discovery'' to Mir, the first for that orbiter, occurred at 16:01 UTC, 4 June 1998 at an altitude of 208 miles. Hatches opened at 2:34&nbsp;pm the same day. At hatch opening, Andy Thomas officially became a member of ''Discovery'''s crew, completing 130 days of living and working on Mir. The transfer wrapped up a total of 907 days spent by seven U.S. astronauts aboard the [[Russia]]n [[space station]] as long-duration crew members. During the next four days, the Mir 25 and STS-91 crews transferred more than {{convert|500|kg}} of water, and almost {{convert|2130|kg}} of cargo experiments and supplies were exchanged between the two spacecraft. During this time, long-term U.S. experiments aboard the Mir were moved into ''Discovery''{{'}}s middeck locker area and the SPACEHAB single module in the orbiter's payload bay, including the Space Acceleration Measurement System (SAMS) and the [[tissue engineering]] co-culture (COCULT) investigations, as well as two crystal growth experiments. The crews also conducted Risk Mitigation Experiments (RMEs) and Human Life Sciences (HLS) investigations. When the hatches closed for undocking at 9:07&nbsp;am, 8 June, and the spacecraft separated at 12:01&nbsp;pm that day, the final Shuttle-Mir docking mission was concluded and Phase 1 of the International Space Station (ISS) program came to an end.
[[File:Mir on 12 June 1998edit1.jpg|thumb|right|250px|''[[Mir]]'' as seen from ''[[Space Shuttle Discovery|Discovery]]'' after undocking]]
STS-91 also carried a prototype of the [[Alpha Magnetic Spectrometer]] (AMS) into space. The AMS, designed to look for dark and missing matter in the universe, was powered up on Flight Day 1. Data originally planned to be sent to ground stations through ''Discovery'''s K<sub>u</sub>-band communications system was recorded on board because of a problem with the K<sub>u</sub>-band system that prevented it from sending high-rate communications, including television signals, to the ground. The system was able to receive uplink transmissions. On 3 June 1998 the crew was able to set up a bypass system that allowed AMS data to be downlinked via S-band/FM communications when the orbiter came within range of a ground station. Data that could not be recorded by ground stations was recorded on board throughout the mission.
The K<sub>u</sub>-band system failure was determined to be located in a component that was not accessible to the crew. The failure prevented television transmission throughout the mission. Television broadcasts from Mir were prevented by a problem between a Russian ground station and the [[mission control center]] outside Moscow, limiting communications to audio only on NASA television.
Other experiments conducted by the Shuttle crew during the mission included a checkout of the orbiter's robot arm to evaluate new electronics and software and the Orbiter Space Vision System for use during assembly missions for the ISS. Also on board in the payload bay were eight [[Get Away Special]] experiments, while combustion, crystal growth and radiation monitoring experiments were conducted in ''Discovery'''s mid-deck crew cabin area.
==See also==
{{Portal|Spaceflight}}
*[[List of human spaceflights]]
*[[List of Space Shuttle missions]]
*[[Outline of space science]]
==References==
{{Reflist}}
==External links==
* [http://science.ksc.nasa.gov/shuttle/missions/sts-91/mission-sts-91.html NASA mission summary] {{Webarchive|url=https://web.archive.org/web/20160304111001/http://science.ksc.nasa.gov/shuttle/missions/sts-91/mission-sts-91.html |date=4 March 2016 }}
* [http://www.nss.org/resources/library/shuttlevideos/shuttle91.htm STS-91 Video Highlights] {{Webarchive|url=https://web.archive.org/web/20120718021601/http://www.nss.org/resources/library/shuttlevideos/shuttle91.htm |date=18 July 2012 }}
{{Shuttle-Mir}}
{{Crewed Mir flights}}
{{Space Shuttle Discovery}}
{{All U.S. Space Shuttle Missions}}
{{Orbital launches in 1998}}
{{Use American English|date=January 2014}}
{{DEFAULTSORT:STS-091}}
[[Category:Spacecraft launched in 1998]]
[[Category:Space Shuttle missions]]