Ten thousand young people and 250 employers are expected at the Big Bang Fair South East.
For the first time, the event at the South of England Showground in Ardingly, is being held over two days, on Wednesday, June 27, and Thursday, June 28.
The aim of the event is to inspire young people to study and pursue science, technology, engineering and maths (STEM) courses and careers.
The event, which is now in its seventh year, is the largest regional Big Bang Fair. It is organised nationally by EngineeringUK.
On the Wednesday, students aged 11 to 18 will be showcasing their projects in the Big Bang UK Young Scientists and Engineers Competition 2018.
The headline sponsor for this year’s event is Gatwick Airport Limited.
Other major sponsors include Crawley Borough Council.