Editing Skylab (section)

== Overview ==
{{As of|{{CURRENTYEAR}}|post=,}} Skylab was the only [[space station]] operated exclusively by the United States. A [[Space Station Freedom|permanent station]] was planned starting in 1988, but its funding was canceled and U.S. participation shifted to the [[International Space Station]] in 1993.

Skylab had a mass of {{convert|199750|lb}} with a {{convert|31000|lb|adj=on}} [[Apollo command and service module]] (CSM) attached<ref name="ep-107-Chapter4"/> and included a workshop, a solar observatory, and several hundred life science and physical science experiments. It was launched uncrewed into [[low Earth orbit]] by a [[Saturn V]] rocket modified to be similar to the [[Saturn INT-21]], with the [[S-IVB]], with Skylab itself being the repurposed third stage. This was the final flight for the rocket more commonly known for carrying the crewed Apollo Moon landing missions.<ref name="1973 Evaluation">{{cite web |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730025115.pdf|title=SATURN V LAUNCH VEHICLE FLIGHT EVALUATION REPORT SA-513 SKYLAB 1|publisher=NASA|year=1973 |access-date=29 May 2016}} {{PD-notice}}</ref> Three subsequent missions delivered three-astronaut crews in the Apollo CSM launched by the smaller [[Saturn IB]] rocket.

=== Configuration ===
Skylab included the [[Apollo Telescope Mount]] (a multi-spectral solar observatory), a multiple docking adapter with two docking ports, an airlock module with [[extravehicular activity]] (EVA) hatches, and the orbital workshop, the main habitable space inside Skylab. Electrical power came from solar arrays and fuel cells in the docked Apollo CSM. The rear of the station included a large waste tank, propellant tanks for maneuvering jets, and a heat radiator. Astronauts conducted numerous experiments aboard Skylab during its operational life.

{| class="wiki table plain row headers"
|+ Component data
|-
! scope="col" rowspan=2 | Component
! scope="col" colspan=2 | Mass<ref name="1973 Evaluation"/><ref name="Gatland">{{cite book |last1=Bono |first1=Phillip |title=Frontiers of Space |last2=Gatland |first2=Kenneth |date=1976 |publisher=MacMillan |edition=1st American Revised <!--|access-date=February 8, 2016--> |page=121 |language=en-us}}</ref><ref name="ep-107-Chapter4">{{cite web |url=https://history.nasa.gov/EP-107/ch4.htm|title=EP-107 Skylab: A Guidebook. Chapter IV: Skylab Design and Operation|date=January 1973 |publisher=NASA History|access-date=29 May 2016 |last1=Belew |first1=L. F. |last2=Stuhlinger |first2=E. }} {{PD-notice}}</ref>
! scope="col" colspan=2 | Habitable volume
! scope="col" colspan=2 | Length
! scope="col" colspan=2 | Diameter
! scope="col" rowspan=2 | Image
|-
! scope="col" | {{abbr|lb|pounds (mass)}}
! scope="col" | {{abbr|kg|kilgrams}}
! scope="col" | {{abbr|ft<sup>3</sup>|cubic feet}}
! scope="col" | {{abbr|m<sup>3</sup>|cubic meters}}
! scope="col" | ft
! scope="col" | m
! scope="col" | ft
! scope="col" | m
|-
! scope="row" | [[Payload fairing|Payload shroud]]
| {{convert|25600|lb|disp=table}} || colspan=2 {{n/a}} || {{convert|56.0|ft|disp=table}} || {{convert|21.6|ft|disp=table}} ||
|-
! scope="row" | [[Apollo Telescope Mount]]
| {{convert|24500|lb|disp=table}} || colspan=2 {{n/a}} || {{convert|14.7|ft|disp=table}} || {{convert|11.3|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 3 - ATM).jpg|100x100px|center]]
|-
! scope="row" | [[Skylab B#Multiple Docking Adapter|Multiple Docking Adapter]]
| {{convert|12000|lb|disp=table}} || {{convert|1140|ft3|disp=table}} || {{convert|17.3|ft|disp=table}} || {{convert|10.5|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 2 - MDA).jpg|100x100px|center]]
|-
! scope="row" | [[Skylab B#Airlock Module|Airlock module]]
| {{convert|49000|lb|disp=table}} || {{convert|613|ft3|disp=table}} || {{convert|17.6|ft|disp=table}} || {{convert|10.5|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 4 - Airlock).jpg|100x100px|center]]
|-
! scope="row" | [[Saturn V instrument unit]]
| {{convert|4600|lb|disp=table}} || colspan=2 {{n/a}} || {{convert|3.0|ft|disp=table}} || {{convert|21.6|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 5 - IU).jpg|100x100px|center]]
|-
! scope="row" | Orbital Workshop
| {{convert|78000|lb|disp=table}}<ref name="ep-107-Chapter4"/> || {{convert|9550|ft3|disp=table}}<ref name="ep-107-Chapter4"/> || {{convert|48.1|ft|disp=table}} || {{convert|21.6|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 6 - OW).jpg|100x100px|center]]
|- style="background:#EAECF0; font-weight: bold;"
! scope="row" style="font-weight: bold;" | Total in orbit
| {{convert|168750|lb|disp=table}} || {{convert|12417|ft3|disp=table}} || {{convert|82.4|ft|disp=table}} || {{convert|21.6|ft|disp=table}} ||
|-
! scope="row" | [[Apollo command and service module|Apollo CSM]]
| {{convert|31000|lb|disp=table}} || {{convert|210|ft3|disp=table}} || {{convert|36.1|ft|disp=table}} || {{convert|12.8|ft|disp=table}} || [[File:Cover3skylabcompontents (cropped 1 - CSM).jpg|100x100px|center]]
|- style="background:#EAECF0; font-weight: bold;"
! scope="row" style="font-weight: bold;" | Total with CSM
| {{convert|199750|lb|disp=table}}<ref name="ep-107-Chapter4"/> || {{convert|12627|ft3|disp=table}} || {{convert|118.5|ft|disp=table}} || {{convert|21.6|ft|disp=table}} ||
|}

=== Operations ===
For the final two crewed missions to Skylab, NASA assembled a backup Apollo CSM/Saturn IB in case an in-orbit rescue mission was needed, but this vehicle was never flown. The station was damaged during launch when the [[Space debris|micrometeoroid shield]] tore away from the workshop, taking one of the main solar panel arrays with it and jamming the other main array. This deprived Skylab of most of its electrical power and also removed protection from intense solar heating, threatening to make it unusable. The first crew deployed a replacement heat shade and freed the jammed solar panels to save Skylab. This was the first time that a repair of this magnitude was performed in space.

The Apollo Telescope significantly advanced solar science, and observation of the [[Sun]] was unprecedented. Astronauts took thousands of photographs of Earth, and the [[Earth Resources Experiment Package]] (EREP) viewed Earth with sensors that recorded data in the [[Visible spectrum|visible]], [[infrared]], and [[microwave]] spectral regions. The record for human time spent in orbit was extended beyond the 23 days set by the [[Soyuz 11]] crew aboard [[Salyut 1]] to 84 days by the [[Skylab 4]] crew.

Later plans to reuse Skylab were stymied by delays in the development of the Space Shuttle, and Skylab's [[decaying orbit]] could not be stopped. Skylab's atmospheric reentry began on July 11, 1979,<ref name=benson371/> amid worldwide media attention. Before re-entry, NASA ground controllers tried to adjust Skylab's orbit to minimize the risk of debris landing in populated areas,<ref name="time19790716"/> targeting the south Indian Ocean, which was partially successful. Debris showered [[Western Australia]], and recovered pieces indicated that the station had disintegrated lower than expected.<ref name= lewis1984/> As the Skylab program drew to a close, NASA's focus had shifted to the development of the Space Shuttle. NASA space station and laboratory projects included [[Spacelab]], [[Shuttle-Mir|Shuttle-''Mir'']], and [[Space Station Freedom|Space Station ''Freedom'']], which was merged into the International Space Station.