An experiment on China’s Tiangong space station has upheld Einstein’s theory of gravity. Scientists dropped two clouds of rubidium atoms made of different isotopes. They fell at the same rate to within 0.05 thousandths of a percent. The result was published in Science Advances on August 28. It tests the weak equivalence principle. The principle says all objects fall at the same rate regardless of what they are made of. Galileo famously demonstrated the idea centuries ago. Doing the test in space removes vibrations and air resistance. That makes it far more precise than ground tests. Physicists say the result is the strongest check of the principle in orbit. It confirms Einstein’s general relativity once again. Future tests may push precision even further. Space tests remove vibrations and air resistance that limit ground experiments. Physicists call it the strongest orbital check of the principle yet. It confirms Einstein’s general relativity once again. Future missions may push precision even further.