NASA scientists explain why the first seven minutes before landing are imperative to success.
ABC News Live Update, Weekdays at 9 AM & 11 AM EST
WATCH the ABC News Live Stream Here: https://www.youtube.com/watch?v=w_Ma8oQLmSM
SUBSCRIBE to ABC NEWS: https://bit.ly/2vZb6yP
WATCH MORE on http://abcnews.go.com/
LIKE ABC News on FACEBOOK: https://www.facebook.com/abcnews
FOLLOW ABC News on TWITTER: https://twitter.com/abc