Washington, Oct. 22 -- After a four-year journey, NASA's robotic spacecraft Osiris-Rex briefly touched down on asteroid Bennu's boulder-strewn surface on Tuesday to collect rock and dust samples dating back to the birth of our solar system. The so-called "Touch-And-Go" or TAG manoeuvre was managed by Lockheed Martin Space in Denver, Colorado, where at 6:12pm an announcer said: "Touchdown declared. Sampling is in progress." The historic mission was 12 years in the making. P12...