“Ingenuity,” a four-pound helicopter carried to Mars on NASA's “Perseverance” lander/rover, made the first powered, controlled flight on another planet April 19, achieving an altitude of 10 feet. Four more flights, going as high as 50 meters high and 600 meters away, are planned in ...
The Defense Department's Space Development Agency wants to blanket Earth with a constellation of low-cost, open-architecture data-relay and missile-tracking satellites whose sheer numbers, along with their 1,000-kilometer-high orbits, would theoretically thwart some modes of interference—but not all. With all going according to plan so far, ...