Building the J-2X Rocket Engine for the Return to the Moon

John Vilja is Pratt and Whitney Rocketdyne's Program Manager in charge of building the latest version of a rocket engine with a very distinguished legacy. He tells us about its development and how it will send us back to the Moon. Emily Lakdawalla's Q&A segment explores what little we know about asteroids that hit Mars. Bruce Betts updates us on the night sky as he and Mat Kaplan announce another prize in our fifth anniversary contest, along with a new space trivia question.

We're celebrating Planetary Radio's fifth anniversary.