Editing Mir (section)

====Third start====
{{See also|Kvant-2|Kristall}}
The launch of [[Soyuz TM-8]] on 5 September 1989 marked the beginning of the longest human presence in space, until 23 October 2010, when this record was surpassed by the ISS.<ref name="Mirrecord"/> It also marked the beginning of ''Mir's'' second expansion. The [[Kvant-2]] and ''[[Kristall]]'' modules were now ready for launch. [[Alexander Viktorenko]] and [[Aleksandr Serebrov]] docked with ''Mir'' and brought the station out of its five-month hibernation. On 29 September the cosmonauts installed equipment in the docking system in preparation for the arrival of ''Kvant''-2, the first of the 20&nbsp;[[tonne]] add-on modules based on the [[TKS spacecraft]] from the [[Almaz]] programme.<ref name="Encyclopedia Astronautica mireo5">{{cite web|title=Mir EO-5|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo5.htm|access-date=18 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070409191451/http://astronautix.com/flights/mireo5.htm|archive-date=9 April 2007 }}{{unreliable source?|date=February 2021}}</ref>{{unreliable source?|date=February 2021}}

[[File:Mir Kvant 1-Base Block-Kvant 2.jpg|thumb|''Mir'' following the arrival of [[Kvant-2|''Kvant''-2]] in 1989]]
After a 40-day delay caused by faulty computer chips, ''Kvant''-2 was launched on 26 November 1989. After problems deploying the craft's solar array and with the automated docking systems on both ''Kvant''-2 and ''Mir'', the new module was docked manually on 6 December. ''Kvant''-2 added a second set of [[control moment gyroscope]]s (CMGs, or "gyrodynes") to ''Mir'', and brought the new life support systems for recycling water and generating oxygen, reducing dependence on ground resupply. The module featured a large airlock with a one-metre hatch. A special backpack unit (known as ''Ikar''), an equivalent of the US [[Manned Maneuvering Unit]], was located inside ''Kvant''-2's airlock.<ref name="Encyclopedia Astronautica mireo5"/><ref name="russianspaceweb.com Kvant-2">{{cite web|title=Spacecraft: Manned: Mir: Kvant-2 Module |publisher=RussianSpaceWeb.com |author=Anatoly Zak |url=http://www.russianspaceweb.com/mir_kvant-2.html |access-date=18 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070424232442/http://www.russianspaceweb.com/mir_kvant-2.html |archive-date=24 April 2007 }}</ref>

[[Soyuz TM-9]] launched [[Mir EO-6|EO-6]] crew members [[Anatoly Solovyev]] and [[Aleksandr Nikolayevich Balandin|Aleksandr Balandin]] on 11 February 1990. While docking, the EO-5 crew noted that three thermal blankets on the ferry were loose, potentially creating problems on reentry, but it was decided that they would be manageable. Their stay on board ''Mir'' saw the addition of the ''Kristall'' module, launched 31 May 1990. The first docking attempt on 6 June was aborted due to an attitude<!--It's supposed to be ATTitude – please don't change this to aLTitude.--> control thruster failure. ''Kristall'' arrived at the front port on 10 June and was relocated to the lateral port opposite ''Kvant''-2 the next day, restoring the equilibrium of the complex. Due to the delay in the docking of ''Kristall'', EO-6 was extended by 10 days to permit the activation of the module's systems and to accommodate an EVA to repair the loose thermal blankets on Soyuz TM-9.<ref name="Encyclopedia Astronautica mireo6">{{cite web|title=Mir EO-6|publisher=Encyclopedia Astronautica|author=Mark Wade|url=http://www.astronautix.com/flights/mireo6.htm|access-date=19 April 2007|url-status=dead|archive-url=https://web.archive.org/web/20070411092726/http://astronautix.com/flights/mireo6.htm|archive-date=11 April 2007}}{{unreliable source?|date=February 2021}}</ref>{{unreliable source?|date=February 2021}}

''Kristall'' contained furnaces for use in producing crystals under microgravity conditions (hence the choice of name for the module). The module was also equipped with biotechnology research equipment, including a small greenhouse for plant cultivation experiments which was equipped with a source of light and a feeding system, in addition to equipment for astronomical observations. The most obvious features of the module were the two [[Androgynous Peripheral Attach System]] (APAS-89) docking ports designed to be compatible with the ''Buran'' spacecraft. Although they were never used in a ''Buran'' docking, they were useful later during the Shuttle-''Mir'' programme, providing a berthing location for US [[Space Shuttle]]s.<ref name="russianspaceweb.com Kristall">{{cite web|title=Spacecraft: Manned: Mir: Kristall Module |publisher=RussianSpaceWeb.com |author=Anatoly Zak |url=http://www.russianspaceweb.com/mir_kristall.html |date=25 May 2010 |access-date=17 December 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110514002915/http://www.russianspaceweb.com/mir_kristall.html |archive-date=14 May 2011 }}</ref>

The [[Mir EO-7|EO-7]] relief crew arrived aboard [[Soyuz TM-10]] on 3 August 1990. The new crew arrived at ''Mir'' with [[quail]] for ''Kvant''-2's cages, one of which laid an egg en route to the station. It was returned to Earth, along with 130&nbsp;kg of experiment results and industrial products, in Soyuz TM-9.<ref name="Encyclopedia Astronautica mireo6"/> Two more expeditions, [[Mir EO-8|EO-8]] and [[Mir EO-9|EO-9]], continued the work of their predecessors whilst tensions grew back on Earth.