View source for Engineering:Soyuz 7K-ST No.16L

{{short description|Aborted 1983 Soviet crewed spaceflight}}

 {{Infobox spaceflight
| name               = Soyuz 7K-ST No.16L
| names_list         = Soyuz T-10a, Soyuz T-10-1
| image              = Soyuz explosion.jpg
| image_caption      = Explosion of Soyuz 7K-ST No.16L
| image_size         = 
| mission_type       = [[Engineering:Salyut 7|Salyut 7]] crew transport
| operator           = [[Company:Energia (corporation)|OKB-1]]
| COSPAR_ID          = 
| SATCAT             = 
| mission_duration   = 5 minutes and 13 seconds
| spacecraft         = Soyuz 7K-ST No.16L
| spacecraft_type    = [[Engineering:Soyuz-T|Soyuz 7K-ST]]
| manufacturer       = OKB-1
| launch_mass        = 6850 kg
| landing_mass       = 2800 kg
| dimensions         = 
| launch_date        = 26 September 1983, 19:37:49 [[Physics:Coordinated Universal Time|UTC]]
| launch_rocket      = [[Engineering:Soyuz-U|Soyuz-U s/n Yu15000-363]]
| launch_site        = Baikonur, Site 1/5
| landing_date       = 26 September 1983, 19:43:02 UTC
| landing_site       = Baikonur ({{cvt|4|km|disp=or}} away from the launch site)
| crew_size          = 2
| crew_members       = [[Biography:Vladimir Georgiyevich Titov|Vladimir Titov]]<br/>[[Biography:Gennadi Strekalov|Gennadi Strekalov]]
| crew_callsign      = Okean ([[Earth:Ocean|Ocean]])
| crew_photo         = 
| crew_photo_caption = 
| crew_photo_size    = 
| orbit_reference    = [[Astronomy:Geocentric orbit|Geocentric orbit]] (planned)
| orbit_regime       = [[Astronomy:Low Earth orbit|Low Earth orbit]]
| orbit_periapsis    = 
| orbit_apoapsis     = 
| orbit_inclination  = 
| orbit_period       = 
| apsis              = gee
| programme          = [[Engineering:Soyuz programme|Soyuz programme]]
| previous_mission   = [[Engineering:Soyuz T-9|Soyuz T-9]]
| next_mission       = [[Engineering:Soyuz T-10|Soyuz T-10]]
}}

'''Soyuz 7K-ST No.16L''', sometimes known as '''Soyuz T-10a''' or '''Soyuz T-10-1''', was an unsuccessful [[Engineering:Soyuz programme|Soyuz mission]] intended to visit the [[Engineering:Salyut 7|Salyut 7]] space station, which was occupied by the [[Engineering:Soyuz T-9|Soyuz T-9]] crew. However, it never finished its launch countdown; the launch vehicle was destroyed on the launch pad by fire on 26 September 1983. The [[Astronomy:Launch escape system|launch escape system]] of the Soyuz spacecraft fired six seconds before the launch vehicle exploded, saving the crew. As of 2022, it remains the only time a launch escape system has been fired before launch with a crew aboard.<!-- Possible Misleading sentence, refer soyuz MS10, the above sentence might also be mentioning that this was the only mission till 2022 that has had a pad abort with crew inside it, if so, please discuss and make an edit --> <ref name="JANE">{{cite web |url=http://www.janes.com/aerospace/civil/news/jsd/jsd030203_3_n.shtml|title=A brief history of space accidents|website=janes.com |archive-url=https://web.archive.org/web/20030204073904/http://www.janes.com/aerospace/civil/news/jsd/jsd030203_3_n.shtml|date=3 February 2003|archive-date=4 February 2003|access-date=20 October 2007}}</ref><ref>{{cite news|url=https://www.bbc.com/news/world-europe-45822845|title=Astronauts escape malfunctioning rocket|publisher=BBC News|date=11 October 2018|access-date=11 October 2018}}</ref>

== Crew ==
{{Spaceflight crew
|terminology = Cosmonaut

|position1   = Commander
|crew1_up    = {{flagicon|Soviet Union}} [[Biography:Vladimir Georgiyevich Titov|Vladimir Titov]]
|flights1_up = Would have been second

|position2   = Flight Engineer
|crew2_up    = {{flagicon|Soviet Union}} [[Biography:Gennadi Strekalov|Gennadi Strekalov]]
|flights2_up = Would have been third
}}

== Mission highlights ==
[[Image:Soyuz T-10-1 abort.jpg|thumb|290px|right|The Soyuz spacecraft narrowly escapes disaster.]]

The crew was sitting on the pad awaiting fueling of the [[Engineering:Soyuz-U|Soyuz-U]] booster to complete prior to liftoff. Approximately 90 seconds before the intended launch, a bad valve caused nitrogen pressurisation gas to enter the RP-1 turbopump of the Blok B strap-on. The pump began spinning up, but with no propellant in it, the speed of rotation quickly exceeded its design limits which caused it to rupture and allow RP-1 to leak out and start a fire which quickly engulfed the base of the launch vehicle. Titov and Strekalov could not see what was happening outside, but they felt unusual vibrations and realized that something was amiss.<ref>{{cite web|url=http://ston.jsc.nasa.gov/collections/TRS/_techrep/TM-2000-209764.pdf|date=March 2000|page=8|title=A Human Factors Evaluation of a Methodology for Pressurized Crew Module Acceptability for Zero-Gravity Ingress of Spacecraft|last=Sanchez|first=Merri J.|publisher=Lyndon B. Johnson Space Center|location=Houston, Texas|access-date=2007-10-20|url-status=dead |archive-url=https://web.archive.org/web/20061005121847/http://ston.jsc.nasa.gov/collections/TRS/_techrep/TM-2000-209764.pdf|archive-date=2006-10-05}} {{PD-notice}}</ref> The launch control team activated the escape system but the control cables had already burned through, and the Soyuz crew could not activate or control the escape system themselves. The backup radio command to fire the LES required 2 independent operators to receive separate commands to do so and each act within 5 seconds, which took several seconds to occur. Then explosive bolts fired to separate the descent module from the service module and the upper launch payload shroud from the lower, the escape system motor fired, dragging the [[Engineering:Orbital module|orbital module]] and [[Engineering:Reentry capsule|descent module]], encased within the upper shroud, free of the booster with an acceleration of 14 to 17''g'' (137 to 167 m/s²) for five seconds. According to Titov, "We could feel the booster swaying from side to side. Then there was a sudden vibration and a jerking sensation as the LES activated".<ref name="americaspace">{{cite web|url=http://www.americaspace.com/?p=42882|date=September 28, 2013|title="We Were Swearing!" Thirty Years Since Russia's Brush With Disaster|last=Evans|first=Ben|access-date=2014-01-24}}</ref>

Just after the escape tower pulled the descent module away, the booster exploded. Its remains burned on the pad for nearly 20 hours. Four [[Engineering:Grid fin|grid fin]]s on the outside of the shroud opened and the descent module separated from the orbital module at an altitude of {{convert|650|m}}, dropping free of the shroud. The descent module discarded its [[Astronomy:Heat shield|heat shield]], exposing the solid-fuel landing rockets, and deployed a fast-opening emergency parachute. Touchdown occurred about {{convert|4|km|spell=in}} from the launch pad. The two crew members were bruised badly after the high acceleration, but were otherwise in good health and did not require any medical attention.<ref name="JANE"/> Upon being greeted by recovery crews, they immediately asked for cigarettes to steady their nerves. The cosmonauts were then given tumbler of vodka to help them relax.<ref name="americaspace"/>

The [[Engineering:KH-11|KH-11]] reconnaissance satellites returned photos of the damaged Site 1 in several runs during late 1983 and early 1984. The descent module was refurbished and later used for [[Engineering:Soyuz T-15|Soyuz T-15]].

The failure's immediate result was the inability to replace the ageing [[Engineering:Soyuz T-9|Soyuz T-9]] return capsule attached to the Salyut 7 space station. This resulted in dire reports in the western media about the cosmonauts remaining aboard Salyut 7 (which had arrived several months before in the Soyuz T-9) being 'stranded' in space, with no ability to return. Official reports by the Soviet news agency TASS gave few details, merely saying that there had been a pad accident and the cosmonauts were rescued by the LES. It was not until several years later during glasnost that the full story of the accident was revealed to the outside world. Years later, in an interview with the United States [[Unsolved:History (American TV network)|History Channel]] regarding the flight, Titov claimed that the crew's first action after the escape rocket fired was to deactivate the spacecraft's [[Astronomy:Flight recorder|cockpit voice recorder]] because, as he put it, "We were swearing".<ref name="americaspace"/>

== See also ==
* {{annotated link|Astronomy:List of spaceflight-related accidents and incidents}}
* {{annotated link|Engineering:Soyuz 7K-T No.39}}
* {{annotated link|Engineering:Soyuz MS-10}}

== References ==
{{reflist}}

== External links ==
* [http://www.russianspaceweb.com/soyuz_sas.html "History of Soyuz Escape System"], Russian Spaceweb website

{{Soyuz}}

[[Category:Crewed Soyuz missions]]
[[Category:Spacecraft launched by Soyuz-U rockets]]

{{Sourceattribution|Soyuz 7K-ST No.16L}}