Service bays, perfect for parachute deployment.

[BurnPrograde]

I've always used the service bays for antennae. Everything else I threw on the sides. Drag? Just over-engineer! It's the Kerbal Way

[StarStreak2109]

For stuff I do not need to get to, for example like batteries, SAS units, probecores etc, I like to use the interstage fairings from procedural fairings. Just lock that stage and you can even match the height of the whole thing to suit your needs. If I need to get to things, I like to use the USI science bays (at least for small bits).

[Guest]

Important things when putting stuff in service bays:

1. Attach other rocket parts to bottom and top of the service bay first. Then you'll only have inside nodes left.

2. Do NOT use angle snap. Without it you don't need to roll stuff to get them inside.

3. Don't put anything even remotely close to the side walls and doors.

#1 won't work if you've done #3, but yes. So long as you are VERY careful building your loadout, and test it before you fly it, you will avoid most major problems. It took me a few days to get the Service Bay sorted out, but once I learned, it works just fine.

[Pecan]

Lost the other thread where this is being discussed ...

I'm having almost no luck at all with service or cargo bays. Doesn't matter what order I add things or whether I use any 'tricks' or not, they just don't seem to behave.

Forget the satellite for the moment - at the front of that bay is a SAS unit and battery, with a couple of solar panels. Lots of extra drag with them and the hottest things on ascent are the solar panels, which receive light and generate power, in the closed bay. How? Even without the panels the SAS and battery are a problem, despite this all being rebuilt several times, because I knew bays are awkward.

Funnily enough, I care less about the oddities of Service bays, even though they show up more often. Rockets are just so much more forgiving than planes that I don't mind the drag and heat as much. It has been disconcerting to see a service bay half-way out of the stack during flight but opening and reclosing the doors (nothing in the way) cures that most of the time.