Everything is ready – tomorrow launch of Soyuz-u rocket with Progress MS-04 on atop is closing with every hour. Penultimate cargo mission to International Space Station is progressing according to schedule.

Yesterday long for 46 m and weighing 313 tons rocket was rolled out from MIK-112 Launcher Integration Facility, where integration process between rocket and Progress MS-04 was conducted. As always rocket was rolled out in horizontal position on special rail platform according to local time. After delivering to “Gagarin’s Start” LC1 launch site State Commission finished all necessary inspections and decided to give agreement to continue launch campaign.

Progress MS-04 will be launched on atop of Soyuz-U rocket tomorrow at 14:52 UTC and will dock to aft of Zvezda ISS module two days later, after passing lasting 34 orbits rendezvous. On 3rd December 2016 at 16:43 +/- 3′ UTC, Progress will perform autonomously approach to International Space Station although remaining under supervision of Mission Control Center specialists supported by two Russian cosmonauts remaining inside ISS: Sergey Ryzhikov and Oleg Novitskiy. After docking, crew members will check tightness of docking port and will start to unload supplies; internal fuel transfer system will pump propellant from tanks of Progress to ISS. After significant loss of weight (2400 kg of supplies will be transferred to ISS from MS-04), Progress will remain docked to Station for 147 days and will be gradually loaded with unwanted equipment trash and unnecessary things.

As we see journey from Baikonur to ISS will take almost three days – it is normal procedure which could be seen also during last mission of Soyuz MS-03. Roscosmos simply is going to devote these additional days in space to conduct series of tests of their latest generation of Progress spacecraft, which entered service last year with launch performed on December 21, 2015.

Mission of MS-04 could be called mission of contrast. MS-04 represents latest technologies incorporated into Progress spacecraft, which remains in service since 1978. Manufactured by RKK Energia it was modified in the late eighties (in 1989 with last flight of in original configuration in 1990) and remained virtually unchanged until 2009. In that year, RKK Energia decided to apply another modifications. Modified Progress, called Progress-M, entered service in 2008 and served well until 2015, when latest version, Progress MS, was presented and launched for the first time. Most significant changes in Progress, comparing to previous versions are adding possibility of deploying satellites from new containers, adding backup electric engines for docking mechanism, installing additional protective panels against micrometeoroids, new communication system with possibility of using Luch data relay satellites in case lack direct contact with ground stations, new navigational system with real time position determination, digital radio and digital camera for monitoring of docking procedure, new telemetry system (Unified Command Telemetry System) instead of Kvant-V and new Kurs-NA docking computer.

Soyuz-U rocket replaced Soyuz-2.1a version as launch vehicle for ISS cargo missions only for two times in 2016. Rocket is manufactured by TsSKB-Progress and started its service in 1973. It is only slightly shorter than 2.1a (46 m instead 46.1 m) and offers lower LEO payload capacity: 6900 kg instead 7020 kg. Soyuz-U and Soyuz-2.1a are identical in diameter (3 m), but differ in weight – U version weighs 313 t. Soyuz-U is supported with four long for 19.6 m boosters equipped with RD-117 engines providing thrust at 838.5 kN – 2.1a boosters are identical with dimensions but are utilizing ┬áRD-107 engines instead with slightly higher thrust at 839.48 kN; both are fueled with LOX/RG-1 propellant. Second stage, which is powered in Soyuz-U with RD-118 engine and is fueled with same propellant as boosters. Propulsion generates thrust at 792.5 kN (RD-108A is utilized in case of 2.1a with equal thrust). Third stage is equipped in both rockets with RD-0110 engine fueled with LOX/RG-1 with thrust at 297.9 kN (298 kN in 2.1a). Second and third stage in both versions are identical with length and diameter: second is 27.1 m long with diameter at 2.98 m, third is 6.7 m long with diameter at 2.66 m.