Japanese billionaire Yusaku Maezawa, who has recently become one of the first tourists who stayed at the International Space Station, reveals his new challenge is to dive deep into the Mariana Trench, speaking at the first press conference after returning to Japan. Together with assistant Yozo Hirano and cosmonaut Alexander Misurkin, Maezawa spent 12 days aboard the ISS, where they made videos documenting daily life in space for his one million YouTube subscribers. IMAGES AND SOUNDBITES