After more than a decade of delays, the most powerful space telescope ever built is set to be launched this weekend. Once in action, the James Webb Space Telescope will replace the Hubble, which has been orbiting Earth for 30 years. WSJ science writer Robert Lee Hotz joins host Zoe Thomas to discuss how the new telescope works and why astronomers say it will be worth the wait. Learn more about your ad choices. Visit megaphone.fm/adchoices