Progress 4

Progress 4

A Progress 7K-TG spacecraft
Mission type	Salyut 6 resupply
Operator	OKB-1
COSPAR ID	1978-090A
SATCAT no.	11040 [1]
Mission duration	23 days
Spacecraft properties
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
Start of mission
Launch date	3 October 1978, 23:09:30 UTC [1]
Rocket	Soyuz-U s/n Ye15000-152
Launch site	Baikonur, 1/5
Contractor	OKB-1
End of mission
Disposal	Deorbited
Decay date	26 October 1978, 16:28 UTC [2]
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee altitude	191 km
Apogee altitude	266 km
Inclination	51.66°
Period	88.8 minutes
Epoch	3 October 1978
Docking with Salyut 6
Docking port	Aft [3]
Docking date	6 October 1978, 01:00:15 UTC
Undocking date	24 October 1978, 13:01:52 UTC
Time docked	18.5 days
Cargo
Mass	2436 kg
Pressurised	1230 kg
Fuel	705 kg
Gaseous	50 kg
Water	420 kg
Progress (spacecraft) ← Progress 3 Progress 5 →

Progress 4 (Russian: Прогресс 4), 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.^[4][5] 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.^[6]

The Progress spacecraft had a dry mass of 6,520 kilograms (14,370 lb), which increased to around 7,020 kilograms (15,480 lb) when fully fuelled. It measured 7.48 metres (24.5 ft) in length, and 2.72 metres (8 ft 11 in) in diameter. Each spacecraft could accommodate up to 2,500 kilograms (5,500 lb) 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.^[6]

Launch

Progress 4 launched on 3 October 1978 at 23:09:30 UTC from the Baikonur Cosmodrome in the Kazakh Soviet Socialist Republic. It used a Soyuz-U rocket.^[4]

Docking

Progress 4 docked with Salyut 6 on 6 October 1978 at 01:00:15 UTC.^[7]

Decay

It remained in orbit until 26 October 1978, when it was deorbited. The deorbit burn occurred at 16:28 UTC.

See also

• 1978 in spaceflight
• List of Progress missions
• List of uncrewed spaceflights to Salyut space stations

References