BEIJING -- Chinese President Xi Jinping has praised a group of middle school students for their efforts in satellite design and said he was pleased with their passion and bravery in scientific exploration.

Xi made the remarks in a letter written to the students from Beijing's Bayi School on Saturday. A small satellite designed and developed by them was launched Wednesday.

The president said he was very pleased to know that the satellite designed by the students would be launched and called on them to become pillars of the country.

Xi hoped that the students would stay hungry for knowledge, keep their interest in scientific exploration and foster their scientific spirit.

He urged the students to inspire more youngsters to embrace science in a bid to contribute to the great rejuvenation of the Chinese nation.

The president also wished the teachers and students in Bayi School a happy new year.

On Sept 9, Xi returned to Bayi School, his alma mater, to visit a laboratory and talk to teachers and students designing the small satellite. He asked them to tell him when the satellite was about to be launched.

The design group told Xi about the satellite launch in a letter and received the reply from him.

The small satellite is the first of its kind designed by China's middle school students. It was launched at Taiyuan Satellite Launch Center and sent into orbit.

The satellite is designed to operate in orbit for 180 days.