Watch: Mark Zuckerberg Chats With ISS Astronauts On Facebook Live

So far, Facebook’s video-streaming platform Facebook Live has been used most prominently to explode a watermelon and to show off a talking Chewbacca mask. But on Wednesday, Mark Zuckerberg himself will use Live to chat with astronauts aboard the International Space Station.

Starting at 12:55 p.m. ET, Zuckerberg will spend 20 minutes on a call with NASA’s Tim Kopra and Jeff Williams and the European Space Agency’s Tim Peake. According to NASA’s Facebook page, Zuckerberg will be asking questions like “What is it like to live and work in microgravity orbiting the Earth?” and “How does the research in space help prepare to send humans on a journey to Mars?”

Users can submit questions here and tune in on NASA’s Facebook page.