After orbiting the near-Earth asteroid Bennu for nearly two years, NASA's OSIRIS-REx spacecraft successfully touched down and reached out its robotic arm to collect a sample from the asteroid's surface on Tuesday. That sample will be returned to Earth in 2023. To achieve this historic first for NASA, a van-size spacecraft had to briefly touch down its arm in a landing site called Nightingale. The site is the width of a few parking spaces. The arm reached out to collect a sample, which could be between 2 ounces and 2 kilograms. Then, the spacecraft backed away to safety.