At 0558 GMT on 22 February 2017, a Soyuz-U rocket rose into the sky from the ice covered fields at its Baikonur launch site in Kazakhstan. It was the last mission the venerable Soyuz-U variant would fly. Aboard was a Progress MS-05 cargo craft on its way to deliver cargo, food and fuel to the International Space Station (ISS) – a mission which looked at one point to be more important following an initially faulty rendezvous of the NASA financed SpaceX Dragon CRS-10 cargo delivery mission.
After the Dragon CRS-10 (Dragon CRS1-10) eventually managed to be grappled and berthed, the Progress MS-05 was able to dock with the Pirs module of the ISS at 0830 GMT on 24 February after a two day approach.
While the long-serving Soyuz-U/U2 rocket series was, overall, a reliable spacecraft launcher, its admittedly low 2.6% failure rate (data from Seradata SpaceTrak) never really improved over its service life. This failure to improve was mainly due to quality control issues that have beset the larger Russian space industry. This factor was exemplified by the previous flight of the Soyuz-U which failed due to a poorly manufactured third stage engine (particle contamination of its oxidiser pump was found to be the likely cause of the failure). That launch failure lost the Progress MS-04 cargo spacecraft and its cargo which was also heading for the ISS
As a precaution, for this flight, the RD-0110 third stage which was built at the same time (in 2014) as the one that failed, was changed out for a later-built one (built in 2016) which was built in a batch not thought to have been affected by the same manufacturing fault.
Updated on 23 February to take account of Dragon CRS-10 rendezvous.
