Tom Rivellini was the lead engineer in the development of Mars Pathfinder's innovative and successful airbags - which became something of a symbol of a new way of designing and flying missions.

P2K: Did you find it hard to get American spacecraft engineers, hardware guys, to take "soft goods" seriously?

Tom Rivellini: (laughs) Getting the JPL hardware engineers to respect and to understand the vagaries of "soft goods" engineering, was probably the hardest part of my job. I spent a lot of time trying to tell people, you know, keep all the corners of your hardware nice and round. And they would be like, "Well, what do you mean by round?" And I'm, like, "I don't know... Would you feel comfortable about rubbing your shirt up against it without tearing it open?" And I spent a lot of time just trying to do these very qualitative discussions with hardware engineers, because it's just too difficult to get this kind of qualitative stuff into drawings.