Into thin air (New Scientist)

成層圏から気密服でダイビングする女性とのインタビュー。いやはや、すごいね。以下引用（斜体強調は引用者による）。

My maximum free-fall speed will be around 1150 kilometres per hour, though because of the thinness of the atmosphere it will feel like only 4 kilometres per hour. The speed I reach will depend on my body position on the way down. If I go into a head-down dive I could go much faster, and I may reach a speed of Mach 1.3. I don't know whether I will create a sonic boom.