When we were there, June 6-13th we did this several times. One day the girls started at 1:15, this was the time we got our assignment and picked up the kimmunicator. On that mission, we didn't get the option to do another assignment. A second day we started later in the day, around 5 PM and they were able to do several assignments. The last day was on Saturday at 3 and they were able to do 3 assignments. My guess is, it varies according to how many people have 'lined' up (scanned their park ticket) to try this.