According to Russian tradition, yesterday was Clean Thursday – a time to purify in preparation to the upcoming orthodox Easter celebration. So, we tried to comply as best we could and cleaned a lot.

First we cleaned the electrical ground support equipment, which also allowed us to correct a couple of things that had been bugging us.

On a roll. (ESA)

We were also got the ok to help with the ‘cleanliness inspection’ of the upper composite before it enters cleanroom 101B. Although it was protected by plastic foil, the upper composite came back to the MIK quite dirty after its visit to the launch pad to be testing. Now nice and shiny it has been transferred into 101B – so all good.

Finally, we also ‘cleaned-up’ on the test results from the sea and land surface temperature instrument, the x-band communication, and the data handling, power and AOCS subsystems – and again all good and no need for further testing there. The propulsion test results were also perfectly fine for the bit already done. The rest will be completed by Saturday when the last test on the thrusters is carried out.

Except for this remaining test, we can confirm tonight that S3B satellite functional verification after transport to the Launch site has been successfully completed – a milestone.

While we were all busy cleaning, some of the team finished charging the battery and tested switching the on.

The now very clean upper composite was disassembled in 101B, the two fairing halves are now mounted on their frames and preparations to fuel the upper stage have started.

The weather in Plesetsk snow but sunny –4°C/+4°C

From the ESA Sentinel-3Blaunch campaign team in Plesetsk

Read more about the Sentinel-3 mission