Touch-and-go: US spacecraft sampling asteroid for return

After almost two years circling an ancient asteroid hundreds of millions of miles away, a NASA spacecraft this week will attempt to descend to the treacherous, boulder-packed surface and snatch a handful of rubble. The drama unfolds Tuesday as the U.S. takes its first crack at collecting asteroid samples for return to Earth, a feat accomplished so far only by Japan. Brimming with names inspired by Egyptian mythology, the Osiris-Rex mission is looking to bring back at least 2 ounces (60 grams) worth of asteroid Bennu, the biggest otherworldly haul from beyond the moon.