Fully loaded with 142 tonnes of solid fuel, the development model of the P120C rocket motor was transferred from the integration building to the test stand at the beginning of June 2018 to prepare for its first static hot firing at Europe’s Spaceport in Kourou, French Guiana.
The P120C has a carbon-fibre casing and is about 13.5 m long and 3.4 m in diameter. It is the largest-ever solid rocket motor built in one piece.
P120C will replace P80 as the first stage motor of Vega-C. Two or four P120Cs will be strapped onto Ariane 6 as boosters for liftoff.
[Source](http://www.esa.int/Our_Activities/Space_Transportation/Highlights/Largest_rocket_motor) with more pics.
> Fully loaded with 142 tonnes of solid fuel, the development model of the P120C rocket motor was transferred from the integration building to the test stand at the beginning of June 2018 to prepare for its first static hot firing at Europe’s Spaceport in Kourou, French Guiana.
> The P120C has a carbon-fibre casing and is about 13.5 m long and 3.4 m in diameter. It is the largest-ever solid rocket motor built in one piece.
> P120C will replace P80 as the first stage motor of Vega-C. Two or four P120Cs will be strapped onto Ariane 6 as boosters for liftoff.
Source with more pics.