Hello!
1) Richard Branson, owner of Virgin Atlantic, has been flying balloons for many years. He still flies them today.
2) I know he has made a transatlantic flight, but I'm not sure when.
3) Have you ever seen a hot-air balloon?
4) Scientists have been working on a new plane but the work is not finished yet.
5) John Glenn has orbited the Earth many times in his life.
6) Mir, the space station, has been orbiting the Earth non-stop since 1986.
7) Captain Lewis is a very experienced Concorde pilot. He has flown the supersonic plane for ten years.
8) They have been building a new terminal in the city so more airlines can use the airport now.