Venera 2MV-2 No.1
{{Short description|Failed Soviet Venus flyby spacecraft}}
{{Use dmy dates|date=March 2020}}
{{Infobox spaceflight
| name = 2MV-2 No.1
| image =
| image_caption =
| mission_type = Venus flyby
| operator = OKB-1
| Harvard_designation = 1962 Alpha Phi 1
| COSPAR_ID = 1962-045A
| SATCAT = 389
| mission_duration = Launch failure
| spacecraft_type = 2MV-2
| manufacturer = OKB-1
| dry_mass =
| launch_mass = {{convert|6500|kg|lb}}
| power =
| launch_date = {{start-date|12 September 1962, 00:59:13|timezone=yes}} UTC
| launch_rocket = Molniya 8K78 {{nowrap|s/n T103-14}}
| launch_contractor =
| decay_date = {{end-date|14 September 1962}}
| orbit_epoch = 1962-09-11, 21:40:00 UTC{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1962-045A|title=Sputnik 21|website=NASA Space Science Data Coordinated Archive|access-date=2 May 2018}}
| orbit_reference = Geocentric
| orbit_regime = Low Earth (achieved)
Heliocentric (intended)
| orbit_semimajor = {{convert|6550|km|mi}}
| orbit_eccentricity = 0.02977
| orbit_periapsis = {{convert|163|km|mi}}
| orbit_apoapsis = {{convert|195|km|mi}}
| orbit_inclination = 64.8 degrees
| orbit_period = 88.07 minutes
| apsis = gee
| programme = Venera
| previous_mission = Venera 2MV-1 No.2
| next_mission = Kosmos 21
}}
Venera 2MV-2 No.1, also known as Sputnik 21 in the West, was a Soviet spacecraft, which was launched in 1962 as part of the Venera programme, and was intended to make a flyby of Venus.{{cite web|url=http://www.russianspaceweb.com/spacecraft_planetary_venus.html|title=Russia's unmanned missions to Venus|last=Zak|first=Anatoly|publisher=RussianSpaecWeb|access-date=28 July 2010}} Due to a problem with the rocket which launched it, it failed to leave low Earth orbit, and reentered the atmosphere a few days later.{{cite web|url=http://www.astronautix.com/project/venera.htm|title=Venera|last=Wade|first=Mark|publisher=Encyclopedia Astronautica|access-date=28 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20120107060752/http://www.astronautix.com/project/venera.htm|archive-date=7 January 2012}} It was the second Venera 2MV-2 spacecraft, both of which failed to leave Earth orbit.{{cite web|url=http://space.skyrocket.de/doc_sdat/venera-2mv-2.htm|title=Venera (2c) (2MV-2 #1)|first=Gunter|last=Krebs|publisher=Gunter's Space Page|access-date=28 July 2010}}
Launch
Venera 2MV-2 No.1 was launched at 00:59:13 UTC on 12 September 1962, atop a Molniya 8K78 carrier rocket flying from Site 1/5 at the Baikonur Cosmodrome.{{cite web|url=http://planet4589.org/space/log/launchlog.txt|title=Launch Log|last=McDowell|first=Jonathan|publisher=Jonathan's Space Page|access-date=28 July 2010}} The rocket performed nominally until cutoff of the Blok I stage, following injection into a low Earth orbit. Following cutoff, one of the oxidiser valves failed to close, and liquid oxygen was allowed to flow into the combustion chamber of one of the vernier thrusters. The vernier thruster exploded,{{cite web|url=http://www.astronautix.com/lvs/soyuz.htm|title=Soyuz|last=Wade|first=Mark|publisher=Encyclopedia Astronautica|access-date=28 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20100107163113/http://astronautix.com/lvs/soyuz.htm|archive-date=7 January 2010}} causing the rocket to tumble out of control. This led to the formation of bubbles in the upper stage oxidiser pump, which caused the upper stage engine to fail less than a second after ignition. It reentered the atmosphere on 14 September 1962, two days after it had been launched.{{cite web|url=http://planet4589.org/space/log/satcat.txt|title=Satellite Catalog|last=McDowell|first=Jonathan|publisher=Jonathan's Space Page|access-date=28 July 2010}}
Spacecraft designation
The designations Sputnik 25, and later Sputnik 21, were used by the United States Naval Space Command to identify the spacecraft in its Satellite Situation Summary documents, since the Soviet Union did not release the internal designations of its spacecraft at that time, and had not assigned it an official name due to its failure to depart geocentric orbit.{{cite web|url=http://filer.case.edu/~sjr16/advanced/20th_soviet_sputnik.html|title=Soviet Craft - Sputnik|last=Robbins|first=Stuart J.|date=11 January 2006|publisher=Journey Through The Galaxy|access-date=28 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20090204083216/http://filer.case.edu/~sjr16/advanced/20th_soviet_sputnik.html|archive-date=4 February 2009}}
See also
{{Portal|Spaceflight}}
References
{{reflist}}
{{Venera}}
{{Orbital launches in 1962}}
Category:1962 in the Soviet Union
Category:Spacecraft launched in 1962
Category:Spacecraft which reentered in 1962
{{USSR-spacecraft-stub}}