There is a ham radio station on the Int. Space Station that the crew members (many of whom have amateur radio licenses) use to talk with hams on the ground. In addition, quite often there is an arrangement made with a school group that allows students to talk with and ask questions of the crew via the ham radio when the ISS is flying over the school’s area.
In this video, NASA astronaut Sunita Williams talks about the big impact that the ISS ham radio contacts with such class room groups had on her. Over 1000 such class room contacts have been made so far.
Find more about the ISS amateur radio program at the ARISS (Amateur Radio on the International Space Station) website. There is info there on how you can arrange for your local school to have a ham radio session with the ISS.