Jacob Bleacher, NASA's chief exploration scientist, says the first two Artemis missions have set the stage for the next moon landing, a moon base and eventually, human exploration of Mars, missions so challenging that only international co-operation makes them possible. »»» Subscribe to CBC News to watch more videos: http://bit.ly/1RreYWS For breaking news, video, audio and in-depth coverage: https://www.cbc.ca/news Follow CBC News on TikTok: https://www.tiktok.com/@cbcnews Subscribe to CBC