Launch Vehicle Dry Run – Testing the roll-out before taking Sentinel-3A onboard
The Breeze-KM upper stage has been equipped with the payload fairing; however without enclosing the Sentinel-3A spacecraft. The purpose of assembling the so-called Upper Composite, occasionally also referred to as Space Head Unit (which will later also comprise the satellite), was the preparation for a dry run. During this exercise, the Upper Composite was covered with thermal protection, put on a dedicated railcar, connected to a mobile air conditioning unit and rolled out this morning from the test and integration facility MIK to the launch pad – following the same procedure as for the actual roll-out shortly before launch.
After arrival at the launch pad earlier today, the “empty” Upper Composite has been lifted onto the Rockot booster which already had been erected inside the service tower a few days ago. The electrical transit lines running along the launch mast will now be connected to the upper stage lines in order to perform an electrical check-out on Breeze-KM as part of the complete launch vehicle. Further, continuity tests of data links will be carried out. These links are needed to communicate from the Undertable Room with the spacecraft when it sits on top of Rockot.
The Upper Composite will then return to MIK to be disassembled again before the Breeze-KM can be fuelled. Subsequent to propellant loading, the upper stage will be mated with the satellite (by that time fully checked and fuelled as well), followed by encapsulation under the payload fairing to repeat the roll-out – only this time for real with Sentinel-3A onboard.