What are the obstacles are for a permanent base on the Red Planet? Ed Butler puts that question to Dennis Bushnell, the chief scientist at Nasa's Langley Research facility. He also hears from Ariel Ekblaw, the founder and lead of the Space Exploration Initiative at Massachusetts Institute of Technology, Chris Lewicki, President and CEO of the firm Planetary Resources and Therese Griebel, the deputy associate administrator for programs within Nasa's Space Technology Mission Directorate.

(Photo: Nasa InSight spacecraft launches onboard a United Launch Alliance Atlas-V rocket on May 5, 2018, from Vandenberg Air Force base in California. Credit: Robyn Beck/AFP/Getty Images)