While passing between earth and the moon, a spacecraft is momentarily located on the line connecting the centers of the two bodies and is at a distance of d = 176 km from a radio antenna on the surface of earth. the distance from the antenna to the moon is denoted by dm. scientists on earth send a command to the spacecraft, which immediately sends back a receipt confirmation signal. how long, in seconds, after the scientists send the command does it take before they learn it was received?