science transmission efficiency

[Stealth2668]

If it says that the transmission efficiency is 30%, that means I only get 30% compared to what I'd get if I recovered it? Does that mean the other 70% is lost permanently since I heard that repeating an experiment yields no additional science?

[UmbralRaptor]

It means that only 30% gets sent back to KSC to be used to unlock parts. The other 70% is still available, but you need to physically return it to Kerbin (and then recover whatever is storing it).

Or to put it another way, the science system is forgiving. (ditto contracts, as you can fulfill the science ones by transmitting 0 value observations)

[Stealth2668]

I see, so why would anyone send 30% instead of just getting the full 100% one time?

[UmbralRaptor]

I see, so why would anyone send 30% instead of just getting the full 100% one time?

Depends on mission design details. If getting back is sufficiently hard (eg: anything from the lower parts of Eve or Jool), transmitting may be the best option, especially if current technologies and funds are limited. Also note that a few kinds of science (crew and EVA reports) get 100% transmission rates.

[cantab]

With the small instruments, and also surface samples, it's often a good approach to transmit a reading and return another. If you have a lab you can extend this approach to the Goo and Materials as well. Just returning one reading doesn't yield all the science for most experiments, and a command pod cannot store duplicate data, so transmitting a reading and returning another gets more science than returning a smaller reading.

Even if you can return your duplicate data - possible by landing a science lab or an EVA kerbal (including in a lawnch chair) which can both hold duplicate readings, or by landing multiple command pods - transmitting gets you science right away. If you want to run multiple missions concurrently, that means you can unlock more tech for your next missions without needing to wait for previous ones to complete. If you play avoiding quickloads and reverts, the transmitted science is safe in the event of a catastrophic failure or can be used to unlock more tech for a rescue mission should the need arise.

[Cerberus738]

Honestly I transmit most of my science back. There are so many points available that it's actually more fun to transmit a few points here and there and be challenged by the limited parts available. I still have experiments returned if I have a Kerbal to bring home. Probes baby!