Working from computer screens in chilly rooms, the force has emerged as a vital part of America’s war machine amid increased competition from China and Russia. It looked more like a satellite ...

When you put your hand out the window of a moving car, you feel a force pushing against you called drag. This force opposes a moving vehicle, and it’s part of the reason why your car naturally slows ...

Two Chinese satellites have rendezvoused with one another more than 20,000 miles above the Earth in what analysts believe is the first high-altitude attempt at orbital refueling. China’s Shijian-21 ...