The value an experiment has as data in a science lab depends on where it is converted into data. So, by steps: Step 1, do experiment Step 2, move experiment to lab Step 3, convert experiment into lab data using the green bubbly flask icon Step 4, do science (aka wait/warp) Step 5, transmit science home. Key bits: In Step 3, when you click that flask the Data value of the experiment depends on what planet you are on when you click it. If it is on Kerbin it’s tiny, other places have more value. Also if the experiment is processed on the planet it was taken on it’s worth more data. And, if the MPL is on the surface it’s worth more data than if it’s processed in orbit (except on Kerbin, the opposite there). Also, the lab can only hold 500 data at a time, so you may hold experiments to process at a later date. Since you can’t convert all the science to data at once I let it sit on the ship for a long time. So it is ready when I need it. Usually by then I can have the data back home and end up never transmitting the experiment. What I do is land a MPL, and a separate ship that does science, doing two of every experiment, then sending one of them to the MPL and returning the other home. I do this with an extra pod on the lander, so I can store two copies of everything. What I’d like to test but have not tested yet, is if you process an experiment on one MPL then transfer it to another, can you process it again for data? Hope that helps.