I'm very new to the Rogue Trader game. We haven't yet even played a game but I'm trying to make up an Astropath. However, I'm a little confused about the short ranged telepathy power. I can't seem to work out what the point of the power is. Everytime I think I've worked it out, the base telepathy power seems to be able to do it too only better.

The power works over less range than the base power

The base power seems to need a free action to use, short ranged telepathy a half action

The short ranged telepathy has less range

I though it was that the power could be used unfettered without risk of rolling for psychic phenomena but then I read that the base power does not have a focus roll and earlier in the chapter it says powers without a power focus roll don't risk phenomena either.

So I'm kind of hoping someone here will be able to clear it up for me.

what exactly is the point of short range telepathy, what does it give me that I didn't already have from being a telepath already?

There's a very simple difference: Thought Sending is just that. If you want the other to be able to respond, you need one of the other powers.

Thank you very much. I've been staring at this for what seems forever and receiving thoughts never even occured to me. It's so obvious I just had one of those doh! moments.