[Edited to clarify I wasn't calling this a bug to start with--this is just an observation. Thanks!] It occurred to me that it might be more efficient to send up one rocket with multiple probes than one probe at a time. I created a rig with nine probes on it--one main probe to serve as a communications relay and to operate a rocket-powered orbiter, and eight others clustered in groups of four around the scaffolding connecting the orbiter to the fuel and engine. The cluster probes each have a QBE for heat resistance, with a modicum of solar panels and antennae and instruments, topped with a M16 chute. Perfect for seeding Eve or Laythe with probes! (They might even survive Duna but I have doubts one M16 is enough.) While there is a chance of failure for one or two probes, I could probably get enough probes to survive to make it worthwhile. (And in my test below I found that was the case with a 75% survival rate on Kerbal.) Once in orbit around their final destination, the main probe would adjust the orbit to allow for aerobraking. Then, it starts releasing probes, a minute or two at a time to allow for some separation, before readjusting its orbit for stability. Before sending these probes half-way across the Kerbol system, I thought I should do a little test closer to home first. So I sent up my rocket, put it in an orbital with the periapsis around 50km, deployed the probes, moved the orbiter back to a stable orbit, and waited. And waited. And waited. Nothing was aerobraking. I switched focus to one of the probes to see what was going in. Then, and only then, did aerobraking happen, with chute and touchdown coming at the end of the second orbit after focus-switch. The rest of the probes kept orbiting happily, totally ignoring that, technically, they were passing through atmosphere that should have degraded their orbit. I had to switch focus to each of them individually and keep the focus on them to get them to aerobrake and land. If I let aerobraking happen on the first orbit, then switched to another probe, the first probe would continue in the degraded orbit, again as if it weren't passing through atmosphere each time, until I switched back again. This isn't entirely a bad thing, since it allows for better control of when (and by extension where) each probe lands. If the destination isn't tidally locked, it's easy to scatter the probes across the world's surface. Even if it is tidally locked, like in the case of Laythe, I presume that if I'm orbiting it and not Jool then I should be able to pick moments in its orbit around Jool which would be good for keeping the probes separated. But it's not realistic. In this test I released all the probes only moments apart, hoping at best for a few kilometers of scattering, not having them more or less evenly spaced all around Kerbal. To scatter them better, I anticipated waiting until my orbiter was climbing out of the atmosphere during its sole aerobraking run, then releasing the probes several minutes apart as I traveled the rest of the orbit, with only minutes to readjust the orbit to prevent further aerobraking of the orbiter. But it's obvious now that it makes no difference--the only difference is in how long I go in-between switching focus between probes. Again, I'm sure Squad wasn't even thinking of scenarios like this when they designed the game. And I'm sure there may be good gameplay reasons not to allow aerobraking for anything except the focused craft. But it's something to think about.