Progress 4
{{Short description|Soviet unmanned Progress cargo spacecraft}}
{{Use British English|date=May 2020}}
{{Use dmy dates|date=May 2020}}
{{Infobox spaceflight
| name = Progress 4
| image = Progress drawing.svg
| image_caption = A Progress 7K-TG spacecraft
| mission_type = Salyut 6 resupply
| operator = OKB-1
| COSPAR_ID = 1978-090A
| SATCAT = 11040 {{cite web|url=http://planet4589.org/space/log/launchlog.txt|title=Launchlog|work=Jonathan's Space Report|access-date=23 December 2017}}
| mission_duration = 23 days
| spacecraft = Progress s/n 105
| spacecraft_type = Progress 7K-TG
| manufacturer = NPO Energia
| launch_mass = 7281 kg
| dry_mass = 7020 kg
| payload_mass = 2436 kg
| dimensions = 7.48 m in length and
2.72 m in diameter
| power =
| launch_date = 3 October 1978, 23:09:30 UTC
| launch_rocket = Soyuz-U s/n Ye15000-152
| launch_contractor = OKB-1
| disposal_type = Deorbited
| decay_date = 26 October 1978, 16:28 UTC {{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-090A|title=Progress 4|work=NASA|access-date=23 December 2017}} {{PD-notice}}
| docking =
{{Infobox spaceflight/Dock
| docking_target = Salyut 6
| docking_type = dock
| docking_date = 6 October 1978, 01:00:15 UTC
| undocking_date = 24 October 1978, 13:01:52 UTC
| time_docked = 18.5 days
}}
| orbit_epoch = 3 October 1978
| orbit_reference = Geocentric
| orbit_regime = Low Earth
| orbit_periapsis = 191 km
| orbit_apoapsis = 266 km
| orbit_inclination = 51.66°
| orbit_period = 88.8 minutes
| apsis = gee
| cargo_mass = 2436 kg
| cargo_mass_press = 1230 kg
| cargo_mass_fuel = 705 kg
| cargo_mass_gas = 50 kg
| cargo_mass_water = 420 kg
| programme = Progress (spacecraft)
| previous_mission = Progress 3
| next_mission = Progress 5
| insignia =
| insignia_caption =
}}
Progress 4 ({{Langx|ru|Прогресс 4|italic=yes}}), was a Progress cargo spacecraft launched by the Soviet Union in 1978 to resupply the Salyut 6 space station. It used the Progress 7K-TG configuration and was the fourth Progress mission to Salyut 6. It carried supplies aboard Salyut 6, as well as equipment for conducting scientific research, and fuel for adjusting the station's orbit and performing manoeuvres.
Spacecraft
Progress 4 was a Progress 7K-TG spacecraft. The fourth of forty three to be launched, it had the serial number 105.{{cite web|url=http://space.skyrocket.de/doc_sdat/progress.htm |title=Progress 1 - 42 (11F615A15, 7K-TG)|first=Gunter|last=Krebs|work=Gunter's Space Page|access-date=26 November 2010}}{{cite web|url=http://planet4589.org/space/log/launchlog.txt |title=Launch Log|last=McDowell|first=Jonathan|work=Jonathan's Space Page|access-date=26 November 2010}} The Progress 7K-TG spacecraft was the first generation Progress, derived from the Soyuz 7K-T and intended for uncrewed logistics missions to space stations in support of the Salyut programme. On some missions the spacecraft were also used to adjust the orbit of the space station.
The Progress spacecraft had a dry mass of {{convert|6520|kg}}, which increased to around {{convert|7020|kg}} when fully fuelled. It measured {{convert|7.48|m}} in length, and {{convert|2.72|m}} in diameter. Each spacecraft could accommodate up to {{convert|2500|kg}} of payload, consisting of dry cargo and propellant. The spacecraft were powered by chemical batteries, and could operate in free flight for up to three days, remaining docked to the station for up to thirty.{{cite book|last1=Hall|first1=Rex D.|last2=Shayler|first2=David J.|title=Soyuz: A Universal Spacecraft|year=2003 |publisher=Springer-Praxis|isbn=1-85233-657-9|pages=239–250}}
Launch
Progress 4 launched on 3 October 1978 at 23:09:30 UTC (4 October at 4:09 a.m. local time) from the Baikonur Cosmodrome in the Kazakh Soviet Socialist Republic. It used a Soyuz-U rocket.
Docking
Progress 4 docked with Salyut 6 on 6 October 1978 at 01:00:15 UTC.{{cite web|url=http://www.astronautix.com/s/salyut6.html|archive-url=https://web.archive.org/web/20161210174048/http://www.astronautix.com/s/salyut6.html|url-status=dead|archive-date=10 December 2016|title=Salyut 6|work=Astronautix|access-date=23 December 2017}}
Decay
It remained in orbit until 26 October 1978, when it was deorbited. The deorbit burn occurred at 16:28 UTC.
See also
{{Portal|Spaceflight}}
References
{{Reflist}}
{{Progress spacecraft}}
{{Orbital launches in 1978}}
Category:Progress (spacecraft) missions
Category:1978 in the Soviet Union
Category:Spacecraft launched in 1978