Mars: when will humans get there?

Sending astronauts to Mars is a daunting prospect. But this will not deter NASA and private companies from trying to put humans on the red planet. Click here to subscribe to The Economist on YouTube: For more from Economist Films visit: Check out The Economist’s full video catalogue: Like The Economist on Facebook: Follow The Economist on Twitter: Follow us on Instagram: Follow us on Medium: @the_economist