Maybe it is mean reversion or maybe there's been a change to the code on the backend because I've definitely noticed that the earnings on the long missions have dopped. They used to average above 2000 starbits but now it is in the 1000 range.
The downside of course is that it takes a lot longer to earn another 12 pack. Almost twice as long since some missions earn even less than 1000. On the other hand, some of the shorter missions are earning more. Like a 5 minute mission earns 600 starbits and sometimes a 5 hour mission earns the same amount.
Of course, too many short missions and they start to gate 'rate limited' so just doing those all day wouldn't work. Still, it is worth switching things around a little rather than just doing the longer missions if you're able to.
