Ellen Stofan

“I always like to say just think you were a doctor with only one patient. You might understand how that person gets sick, how they get better, but you understand nothing about the progression of disease or how humans in general get ill. Now take an Earth scientist: you only have one planet to study.”

“With the mission to Mars, the whole world wants to get involved. So we actually have 13 different space agencies from around the world working on the global exploration road map.”

“We have to ask, 'How can we break a huge challenge like sending humans to Mars into a series of doable, affordable steps? How can we break that problem down into chunks in order to keep making progress?'”

“To avoid congestion, I get up at 5:10, grab a slice of raisin toast, and leave the house at 6 A.M. My husband, Tim Dunn, who works for an environmental agency, is still asleep when I slip out, and I find that rather annoying.”

“You see countries like India really investing in their space program because they see it as inspirational and good for their economy.”

“As chief scientist, it's sort of my job to look at bridges between what we do and to see the connections. But when we try to understand how are planets around other stars habitable... to looking back at the Earth - how are the changes that are taking place, how are they going to affect humanity?”

“Water-based life is very much an Earth-centric view, and we can push the envelope on that here in our own solar system. We have the methane seas of Titan.”

“The public has an incredible capacity for appreciating the wonder of our planet, our solar system, our universe.”

“We actually look to the scientific community to kind of come back to NASA and tell us what the priorities should be. And then at NASA, we try to look within our budget and say, 'What can we accommodate, and what are the most important things for the nation?'”

“Every time I give a talk, I ask the audience - especially if it's kids - how many want to go to Mars. At least half raise their hands. I don't think there's going to be any shortage of volunteers.”

“I grew up in this business... A lot of my life has been centered around this question about how NASA is helping us to understand our own home planet... and to understand our place in the universe.”

“We're not going to get humans to Mars until at least the mid-2030s, and the world is going to change by then.”

“When you look at Venus and the Earth, they formed at about the same place in the solar system. They're made of about the same materials; they're about the same size.”

“We're going to understand that there is life on other bodies in the solar system.”

“People see space as a place where you go and cooperate.”

“I wish someone would redo 'Dune.'”

“There's a huge question of whether you really need water for life.”

“Humans can actually read a landscape, go through a lot of rocks - crack them open, throw them, pick up the next one. Rovers are great - they do amazing science - but it is a lot more tedious process; they go much less far than a human can cover in a day.”

“What we expect to find, certainly in our own solar system, are probably simple single or multiple-cell forms of life. To get to intelligent life takes stability of conditions over huge, long periods of time.”

“I'm actually a NASA brat. My father was a rocket scientist. He started working at NASA before it was NASA in 1959.”