Answer:
A future space mission to Titan, Saturn's intriguing moon enveloped in clouds, might deploy a blimp to float around the thick atmosphere and survey the sand dunes and carved valleys below.
But the blimp's ability to communicate would be limited. A message would take about an hour and a half to travel more than 800 million miles to Earth, and any response would take another hour and a half to get to Titan.
Three hours would be a long time to wait if the message were: "Help! I'm caught in a downdraft. What do I do?" Or if the blimp were to spot something unusual — an eruption of an ice volcano — it might have drifted away before it received the command to take a closer look. The eruption may also have ended by then.