Complex sentence: Phạm Tuân (born February 14,1947) was the first Vietnamese cosmonaut, the first Asian in space-and by extension, the first person from the Developing or Third World to fly into space.
Split into simpler sentences: Phạm Tuân (born February 14,1947) was the first Vietnamese cosmonaut, the first Asian in space. And by extension, he was also the first person from the Developing-or Third World-to fly into space.