View source for STS-55

{{Short description|1993 American crewed spaceflight}}
{{Use American English|date=January 2014}}
{{Use mdy dates|date=September 2023}}
{{Infobox spaceflight
| name               = STS-55
| image              = STS-55 Spacelab.jpg
| image_caption      = Spacelab Module LM1 in ''Columbia''{{'}}s payload bay, serving as the [[Spacelab]] D-2 laboratory
| names_list         = [[Space Transportation System]]-55<br />[[Spacelab]] D-2
| mission_type       = [[Micro-g environment|Microgravity]] research
| operator           = [[NASA]] and [[German Aerospace Center|DLR]]
| mission_duration   = {{time interval|April 26, 1993, 14:50:00|May 6, 1993, 14:29:59|show=dhms|sep=,}}
| distance_travelled = {{cvt|6701603|km}}
| orbits_completed   = 160
| spacecraft         = {{OV|102}}
| launch_mass        = 
| landing_mass       = {{cvt|103191|kg}}
| payload_mass       = {{cvt|11539|kg}}
| crew_size          = 7
| crew_members       = {{Unbulleted list|[[Steven R. Nagel]]|[[Terence T. Henricks]]|[[Jerry L. Ross]]|[[Charles J. Precourt]]|[[Bernard A. Harris Jr.]]|[[Ulrich Walter]]|[[Hans Schlegel]]}}
| launch_date        = {{Start date text|April 26, 1993, 14:50:00|timezone=yes}}{{nbsp}}[[Coordinated Universal Time|UTC]] (10:50{{nbsp}}am{{nbsp}}[[Eastern Daylight Time|EDT]])
| launch_site        = [[Kennedy Space Center|Kennedy]], [[Kennedy Space Center Launch Complex 39A|LC-39A]]
| launch_contractor  = [[Rockwell International]]
| landing_date       = {{End date text|May 6, 1993, 14:29:59|timezone=yes}}{{nbsp}}UTC (7:29:59{{nbsp}}am{{nbsp}}[[Pacific Daylight Time|PDT]])
| landing_site       = [[Edwards Air Force Base|Edwards]], Runway{{nbsp}}22
| orbit_reference    = [[Geocentric orbit]]
| orbit_regime       = [[Low Earth orbit]]
| orbit_periapsis    = {{cvt|304|km}}
| orbit_apoapsis     = {{cvt|312|km}}
| orbit_inclination  = 28.45°
| orbit_period       = 90.70 minutes
| apsis              = gee
| instruments        = 
| insignia           = Sts-55-patch.png
| insignia_caption   = STS-55 mission patch
| crew_photo         = Sts-55 crew.jpg
| crew_photo_caption = Standing: [[Bernard A. Harris Jr.|Harris]], [[Hans Schlegel|Schlegel]], [[Jerry L. Ross|Ross]], [[Ulrich Walter|Walter]]<br />Seated: [[Terence T. Henricks|Henricks]], [[Steven R. Nagel|Nagel]], [[Charles J. Precourt|Precourt]]
| programme          = [[Space Shuttle program]]
| previous_mission   = [[STS-56]] (54)
| next_mission       = [[STS-57]] (56)
}}

'''STS-55''', or '''Deutschland 2''' ('''D-2'''), was the 55th overall flight of the [[NASA]] [[Space Shuttle]] and the 14th flight of Shuttle ''[[Space Shuttle Columbia|Columbia]]''. This flight was a multinational [[Spacelab]] flight involving 88 experiments from eleven different nations. The experiments ranged from [[biology]] sciences to simple [[Earth observation]]s.

== Crew ==
{{Spaceflight crew
| terminology = Astronaut
| position1   = Commander
| crew1_up    = {{Flagicon|USA}} [[Steven R. Nagel]] [[Image:Solid blue.svg|8px|Member of Blue Team]]
| flights1_up = Fourth and last

| position2   = Pilot
| crew2_up    = {{Flagicon|USA}} [[Terence T. Henricks]] [[Image:Solid blue.svg|8px|Member of Blue Team]]
| flights2_up = Second

| position3   = Mission Specialist 1
| crew3_up    = {{Flagicon|USA}} [[Jerry L. Ross]] [[Image:Solid blue.svg|8px|Member of Blue Team]]
| flights3_up = Fourth

| position4   = Mission Specialist 2<br />Flight Engineer
| crew4_up    = {{Flagicon|USA}} [[Charles J. Precourt]] [[Image:Solid red.svg|8px|Member of Red Team]]
| flights4_up = First

| position5   = Mission Specialist 3
| crew5_up    = {{Flagicon|USA}} [[Bernard A. Harris Jr.]] [[Image:Solid red.svg|8px|Member of Red Team]]
| flights5_up = First

| position6   = Payload Specialist 1
| crew6_up    = {{Flagicon|GER}} [[Ulrich Walter]]
| flights6_up = Only
| agency6_up  = [[German Aerospace Center|DLR]] [[Image:Solid blue.svg|8px|Member of Blue Team]]

| position7   = Payload Specialist 2
| crew7_up    = {{Flagicon|GER}} [[Hans Schlegel]]
| flights7_up = First
| agency7_up  = [[German Aerospace Center|DLR]] [[Image:Solid red.svg|8px|Member of Red Team]]
| notes       = [[Image:Solid blue.svg|8px|Member of Blue Team]] Member of Blue Team<br>[[Image:Solid red.svg|8px|Member of Red Team]] Member of Red Team
}}
{{Spaceflight crew
| terminology = Astronaut
| crew        = backup

| position1   = Payload Specialist 1
| crew1_up    = {{Flagicon|GER}} [[Gerhard Thiele]]
| agency1_up  = [[German Aerospace Center|DLR]]

| position2   = Payload Specialist 2
| crew2_up    = {{Flagicon|GER}} [[Renate Brümmer]]
| agency2_up  = [[German Aerospace Center|DLR]]
}}

=== Crew seat assignments ===
{| class="wikitable" style="text-align:center"
! Seat<ref>{{cite web|title=STS-55|url=http://spacefacts.de/mission/english/sts-55.htm|publisher=Spacefacts|access-date=July 29, 2024}}</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| Nagel
|-
! 2
|colspan=2| Henricks
|-
! 3
| Ross
| Harris
|-
! 4
|colspan=2| Precourt
|-
! 5
| Harris
| Ross
|-
! 6
|colspan=2| Walter
|-
! 7
|colspan=2| Schlegel
|}

== Launch ==
''Columbia'' was initially scheduled to launch in late February 1993. However, this date slipped to early March 1993 due to concerns with the tip-seal retainers in the main engines' oxidizer turbopumps. All three turbopumps were replaced at the pad but later inspection revealed the retainers to be in good condition. Further delays were caused by the burst of a hydraulic flex hose in the aft compartment during the Flight Readiness Test (FRT). The lines were removed and inspected and three replacements were installed.<ref name="Fricke">{{Cite report |url=https://ntrs.nasa.gov/api/citations/19940023696/downloads/19940023696.pdf |title=STS-55 Space Shuttle mission report |last=Fricke |first=Robert W. |date=1993-07-01 |publisher=NASA |access-date=2024-10-16}}</ref>

{{LaunchAttempt
| date1           = March 22, 1993, 9:51:00
| result1         = Scrubbed
| reason1         = Technical
| decision_date1  = March 22, 1993, 9:50
| decision_clock1 = −00:00:03
| weathergo1      = 
| notes1          = Pad abort: oxidizer purge valve jammed on a chunk of O-ring, all 3 main engines changed.<ref>{{cite web|url=https://www.space.com/26916-nasa-astronaut-steven-nagel-obituary.html|title=Former NASA Astronaut Steven Nagel Dies at 67|date=August 22, 2014|publisher=Space.com|access-date=March 15, 2020|archive-date=December 2, 2019|archive-url=https://web.archive.org/web/20191202230618/https://www.space.com/26916-nasa-astronaut-steven-nagel-obituary.html|url-status=live}}</ref>
| date2           = April 24, 1993 10:52
| result2         = Scrubbed
| reason2         = Technical
| decision_date2  = 
| decision_clock2 = 
| weathergo2      = 
| notes2          = Possible faulty reading with one of the inertial measurement units.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-55.html|title=NASA – STS-55|publisher=NASA|access-date=February 12, 2022|archive-date=July 5, 2015|archive-url=https://web.archive.org/web/20150705081117/http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-55.html|url-status=live}} {{PD-notice}}</ref>
| date3           = April 26, 1993, 10:50
| result3         = Success
| reason3         = 
| decision_date3  = 
| decision_clock3 = 
| weathergo3      = 
| notes3          = Launched
}}

== Mission highlights ==
''Columbia'' carried to orbit the second reusable German Spacelab D-2 and demonstrated the shuttle's ability for [[Multilateralism|international cooperation]], [[Space exploration|exploration]], and [[Scientific method|scientific research in space]]. The Spacelab module and an exterior experiment support structure contained in ''Columbia''{{'}}s payload bay comprised the Spacelab D-2 payload. The first German Spacelab flight, D-1, flew Shuttle mission [[STS-61-A]] in October 1985. The [[United States]] and [[Germany]] gained valuable experience for future space station operations.

The D-2 mission, as it was commonly called, augmented the German [[Micro-g environment|microgravity research]] program started by the D-1 mission. The [[German Aerospace Center]] (DLR) had been tasked by the [[German Aerospace Center|German Space Agency]] (DARA – Deutsche Agentur für Raumfahrtangelegenheiten) to conduct the second mission. DLR, NASA, the [[European Space Agency]] (ESA), and agencies in [[France]] and [[Japan]] contributed to D-2's scientific program. Eleven nations participated in the experiments. Of the 88 experiments conducted on the D-2 mission, four were sponsored by NASA.

The crew worked in two shifts around-the-clock to complete investigations into the areas of [[Fluid mechanics|fluid physics]], [[materials science]]s, [[List of life sciences|life sciences]], biological sciences, [[technology]], Earth observations, [[atmospheric physics]], and [[astronomy]]. Many of the experiments advanced the research of the D-1 mission by conducting similar tests, using upgraded processing hardware, or implementing methods that took full advantage of the technical advancements since 1985. The D-2 mission also contained several new experiments which were not previously flown on the D-1 mission.

The mission surpassed the 365th day in space for the Space Shuttle fleet and the 100th day of flight time in space for ''Columbia'', the fleet's oldest [[Space Shuttle orbiter]], on its fourteenth flight.

D-2 marked the first [[Telerobotics|telerobotic]] capture of a free floating object by flight controllers in [[Germany]]. The crew conducted the first intravenous saline solution injection in space as part of an experiment to study the human body's response to direct fluid replacement as a countermeasure for amounts lost during space flight. They also successfully completed an in-flight maintenance procedure for collection of orbiter [[Wastewater|waste water]], which allowed the mission to continue.

STS-55 crew members participated in two [[amateur radio]] experiments, SAREX II from the United States and the German SAFEX. These experiments allowed students and amateur radio operators from around the world to talk directly with the Space Shuttle in orbit and participated in a SpaceMedicine conference with the [[Mayo Clinic]].

== See also ==
{{Portal|Spaceflight}}
* [[List of human spaceflights]]
* [[List of Space Shuttle missions]]
* [[Outline of space science]]
* [[Space Shuttle]]
* [[Space Shuttle abort modes]]

== References ==
{{Reflist|30em}}

== External links ==
* [http://science.ksc.nasa.gov/shuttle/missions/sts-55/mission-sts-55.html NASA mission summary] {{Webarchive|url=https://web.archive.org/web/20120222065645/http://science.ksc.nasa.gov/shuttle/missions/sts-55/mission-sts-55.html |date=February 22, 2012 }}
* [http://www.nss.org/resources/library/shuttlevideos/shuttle55.htm STS-55 Video Highlights] {{Webarchive|url=https://web.archive.org/web/20141223140659/http://www.nss.org/resources/library/shuttlevideos/shuttle55.htm |date=December 23, 2014 }}
* [https://science.ksc.nasa.gov/mirrors/images/html/STS55.htm NASA STS-55 official photo gallery] {{Webarchive|url=https://web.archive.org/web/20200317214916/https://science.ksc.nasa.gov/mirrors/images/html/STS55.htm |date=March 17, 2020 }}

{{Space Shuttle Columbia}}
{{European human spaceflight}}
{{All U.S. Space Shuttle Missions}}
{{Orbital launches in 1993}}

[[Category:Space Shuttle missions]]
[[Category:Edwards Air Force Base]]
[[Category:Spacecraft launched in 1993]]
[[Category:Space programme of Germany]]