Before a Formula 1 car hits the track for the first official test session it has to undergo a set of milestones. These include the first time the engine is started, the team presentation, and most crucial of all the shakedown of the car.
A shakedown usually occurs behind closed doors and is done to ensure two things. The first is, of course, to ensure that the driver is comfortable in the car but the main reason that a team conducts a shakedown is to make sure that the car is mechanically sound and that all the various systems are in place.
While nine out of the ten teams on the grid will carry over their chassis from 2020 into 2021, the McLaren team who have signed a deal with Mercedes will have to pay close attention to the feedback from their drivers during their shakedown in Silverstone.
Pirelli provides every team with a special compound of tyres for these events and the teams are restricted to just 100 kilometres of running or roughly 20 laps. This means that if a team plans on running two drivers on the day, they will need to determine how the allocation of those 100 kilometres will work.
The F1 teams are allowed two-filming days of which one of those days in most cases is used for the purpose of the shakedown. These two days are the only way teams are legally allowed to test their cars outside the agreed-upon official test sessions.