Scanning arms and probe cores

[Klapaucius]

I'm doing my first career and have not had to do science scans before.  I have a contract for a "complex scan".  Is this something I can do with the small rover arm, or do I need the big one?  For that matter, is there an actual gameplay difference between them?

 

Same goes for probe cores.  Once you have SAS and unmanned capability, what are you getting for the extra money?  What does a 2700 fund drone core do that an OKTO does not?  What makes the HECS 200 more than the OKTO?  I cannot find any discernible difference.

[jimmymcgoochie]

There is a difference- the small arm gets 33% of the available science, the medium one 66% and the large one 100%, and this doesn’t change if you repeat the experiment with the same arm- though you can revisit the same type of surface feature with a better arm in the future to get the rest of the science.

As for probe cores, there are a few differences between them- the HECS gets pro/retrograde holding and possibly a slightly better reaction wheel, whereas the OKTO only does basic SAS; the Stayputnik has no SAS and no reaction wheels, the QBE gets basic SAS but no reaction wheels, the OKTO2 gets radial and normal hold too but no reaction wheels and the HECS2 gets all the SAS modes and pretty powerful reaction wheels. RGUs (drone cores) get all the SAS modes too but also have a unique ability where a pilot on a different ship in flight can remote pilot the craft if they have a comms connection, giving the probe full control even if it can’t communicate all the way back to Kerbin; I’m not sure which craft needs the RGU on it though, I think it’s the one being controlled rather than the one doing the controlling?