RACHEL MARTIN, HOST:
Good morning. I'm Rachel Martin. From the far reaches of space to the depths of our oceans, Kathy Sullivan has just about seen it all. Sullivan recently became one of only eight people ever to visit Challenger Deep. This is the deepest point of the ocean, a crevice in the Marianas Trench. This comes 36 years after Sullivan became the first American woman to walk in space. That makes her the only human being to have done both. Transcript provided by NPR, Copyright NPR.