POWER!!!

[W. Kerman]

So, I want one craft to go to Eve on a flyby, but dropping a science atmosphere probe to land there, then I want the main craft to go on a Jool flyby that hits the upper atmosphere and drops a second probe there, but I only have batteries and solar panels. How many solar panels do I need to transmit all data?

[Alshain]

Not a problem at Eve, but from Jool?  Solar panels are going to be very ineffective.  Do you not have the fuel cells yet?

Edited August 2, 2016 by Alshain

[stibbons]

Read up on antenna properties. Depending on which antenna you're using, you'll be able to calculate how much power you'll consume per second while transmitting. From there you just need to ensure that your total output from your solar panels is close to or exceeds that. The wiki entry on solar panels also gives figures for how solar generation efficiency varies with distance from the sun, which you'll need to take in to account when figuring out how much charge you'll be getting.

[The Raging Sandwich]

I recommend RTGs be used for transmitting and other science past Duna. Unless you don't have RTGs, fuel cells would work too.

[IWanttobeEVA]

You really only need one solar panel to transmit scientific data from a probe, you just want just slightly more battery power to transmit the data from the most demanding instrument you have on board with the antenna on the probe. Then wait until the batteries recharge to do the next measurement.

You can calculate how many batteries you need, or just build your probe and test out the scientific transmission on the launch pad and add or subtract batteries as needed. The trouble with all solar power is the energy flow has to keep up with the data transmission for the entire transmission or it will abort and no data will be sent. Then I think it's better to have the power stored already and the batteries will recharge eventually even if you have very weak energy flow. Also, even if you have a bad landing you still might be able to return some data. 

[magnemoe]

10 hours ago, stibbons said:

Read up on antenna properties. Depending on which antenna you're using, you'll be able to calculate how much power you'll consume per second while transmitting. From there you just need to ensure that your total output from your solar panels is close to or exceeds that. The wiki entry on solar panels also gives figures for how solar generation efficiency varies with distance from the sun, which you'll need to take in to account when figuring out how much charge you'll be getting.

This, its often useful to use slow antennas on probes and small lander to minimize power drain. On huge science bases the large antennas are nice to transmit all the stored science. 
Just having an probe with science instruments and batteries on launchpad show how much battery is needed. 

Far out lots of batteries and fuel cells and / or rtg is nice. 
back in earlier versions you could time warp and this increased power generation but not transmission speed however this feature is fixed. 

 

[Corona688]

18 hours ago, W. Kerman said:

So, I want one craft to go to Eve on a flyby, but dropping a science atmosphere probe to land there, then I want the main craft to go on a Jool flyby that hits the upper atmosphere and drops a second probe there, but I only have batteries and solar panels. How many solar panels do I need to transmit all data?

You could probably do with 5K-10K at a very rough guess.  Last time I went to Jool was before the science revamp, when you could continuously re-transmit data to approach the recover value (and when the atmosphere analyzer data size was ENORMOUS).  I sent a drop-probe with 30,000 battery and it did a reasonable job.

Not sure you can wait for fuel cells unless your drop-probe has wings to linger with.  Jool's atmosphere is thick, but its gravity is heavy, it will suck you down with surprising speed despite parachutes.

I usually don't see any point in using any antenna but the basic Communotron.  The DTS-1 is slightly more power efficient, but only SLIGHTLY and it looks breakable.  Even when speed matters, you can just attach more than one Communotron, whenever you hit 'transmit' and one's busy it'll use another.

Edited August 3, 2016 by Corona688