NASA astronauts Joe Acaba, left, and Mark Vande Hei, right, answer questions from the audience after speaking about their time onboard the International Space Station, Friday, June 15, 2018 at NASA Headquarters in Washington. Acaba and Vande Hei answered questions from the audience and spoke about their experiences aboard the International Space Station for 168 days as part of Expedition 53 and 54. Photo Credit: (NASA/Joel Kowsky)