Communicating from deep space

[GungaDin]

So far I have not given any careful attention to communication but now I have to.  I designed a probe using a stayputnik and some other parts along with 2 HG5 high gain antenni and some cheap solar panels and sent it into orbit around the moon.  there it did some experiments and transmitted them back to Earth.    It was so successful that I decided to keep going and try to reach a nearby asteroid called Ryugu.   About half way there I checked up on my probe and found that it was not in communication any more (communication line is red) even though it still has plenty of electricity and the antenna are still deployed.  Any notion of why I lost touch.  Also I still have control of the craft which I don't understand since I shouldn't be able to send command...

Any ideas on this?  Thanks.

[RainThorn]

35 minutes ago, GungaDin said:

So far I have not given any careful attention to communication but now I have to.  I designed a probe using a stayputnik and some other parts along with 2 HG5 high gain antenni and some cheap solar panels and sent it into orbit around the moon.  there it did some experiments and transmitted them back to Earth.    It was so successful that I decided to keep going and try to reach a nearby asteroid called Ryugu.   About half way there I checked up on my probe and found that it was not in communication any more (communication line is red) even though it still has plenty of electricity and the antenna are still deployed.  Any notion of why I lost touch.  Also I still have control of the craft which I don't understand since I shouldn't be able to send command...

Any ideas on this?  Thanks.

Red line= red bar = weak signal (green, orange, red)

no line = no bar = no signal

Edited November 14, 2019 by RainThorn

[bewing]

Even if you have no direct signal, you usually still have partial control of the craft -- depending on your game settings. That happens when the probe icon is yellow, as in the above image. The better your probe core, the more control you have, even with no direct signal. (The stayputnik is the worst of all the probe cores.)

To calculate the strength and maximum range of your signal, you use the signal strength formula: strength = sqrt (antenna1_power * antenna2_power)

It gets a little more complicated if you have multiple antennas on your craft.

The default power of an HG5 antenna is 5 million. That power gets modified by your "antenna range modifier" in your game settings. Two HG5 antennas together have a power of around 7 million.

To calculate your signal strenth to KSC, you need to know the power of your Tracking Station, by opening its menu. Then use the above formula.

[AHHans]

8 hours ago, GungaDin said:

Any notion of why I lost touch.

To summarize the answers already given: you lost touch because you left communications range of the HG-5s. (They are only good for communication within the Kerbin SOI.)

A very helpful explanation of the communication in stock KSP is the wiki page about CommNet.

[Fierce Wolf]

Upgrade your Antenna Building at the space center. That way you can get control back from the sat

[GungaDin]

Thanks you all.  Too late to catch my probe and install new equipment but I will upgrade my ground station and hope to get it to phone home again.