Smile: aerial view of a booster leaving storage

An aerial view of a P120C solid-propellant rocket motor as it leaves the Booster Storage Building at Europe's Spaceport, 19 February 2026.

This rocket motor will be used as the first stage for the Vega-C rocket flight VV29 that will take ESA's Smile mission to orbit.

Vega-C is a single-body rocket nearly 35 m tall with that weighs 210 tonnes on the launch pad. Vega-C's P120C first stage provides thrust at liftoff. The carbon fibre structure weighs about 8000 kg and carries over 140 tonnes of solid propellant. During its two-minute burn this motor delivers an average thrust of 4500 kN – equivalent to the output of 15 modern airliner engines. The P120C does double service, with either two or four of these solid fuel motors used as boosters for ESA’s Ariane 6 rocket.

Smile (the Solar wind Magnetosphere Ionosphere Link Explorer) is a joint mission between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS).

Smile will use four science instruments to study how Earth responds to the solar wind from the Sun. In doing so, Smile will improve our understanding of solar storms, geomagnetic storms and the science of space weather.

ESA is responsible for providing Smile’s payload module (which carries three of the four science instruments), one of the spacecraft’s four science instruments (the soft X-ray imager, SXI), the launcher, and the Assembly Integration and Testing facilities and services. ESA contributes to a second science instrument (the ultraviolet imager, UVI) and the mission operations once Smile is in orbit.

CAS provides the other three science instruments and the spacecraft platform, and is responsible for operating the spacecraft in orbit.

[A tall white building with open bay door can be seen as a yellow transporter is just outside with a large white cylinder standing on it – the P120C rocket motor. Four humans are standing by the transporter illustrating how tall the motor is. They sky is dark grey. Two cars are parked nearby.]