Complex sentence: He was the third Latin American to go into space; the first was Arnaldo Tamayo Méndez from Cuba in 1980, and second was Rodolfo Neri Vela from Mexico in 1985.
Split into simpler sentences: He was the third Latin American to go into space. The first Latin American to go into space was Arnaldo Tamayo Méndez from Cuba in 1980, and second was Rodolfo Neri Vela from Mexico in 1985.