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 a group of students from Beijing's Bayi School Saturday. A small satellite designed and developed by them was launched Wednesday.

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