Motoring on the ground limits specify the duration for motor 1 and for motors 2 through 5?

• A. Motor 1: 90 seconds on, 5 minutes off; Motors 2-5: 30 seconds on, 5 minutes off
• B. Motor 1: 60 seconds on, 2 minutes off; Motors 2-5: 60 seconds on, 2 minutes off
• C. Motor 1: 120 seconds on, 5 minutes off; Motors 2-5: 30 seconds on, 10 minutes off
• D. Motor 1: 30 seconds on, 5 minutes off; Motors 2-5: 120 seconds on, 5 minutes off

Answer: (A)

On the ground, you manage heat by using duty cycles that pair short bursts of activity with long cooldowns. Motor 1 is allowed a longer burst, 90 seconds on, because it’s handling the primary task and can tolerate a bit more heat per cycle, while the other four are limited to 30 seconds on to keep heat buildup lower. In every case, a 5-minute off period follows to let components cool safely before the next burst. This pattern provides enough operational time for each motor without exceeding safe temperatures, which is why this schedule fits best. Shorter bursts or longer on-times without adequate cooldown would risk overheating, so the paired 90 seconds vs 30 seconds on, both with 5 minutes off, is the appropriate timing.