What I normally do when I am deciding on what to make next: I think about what is fun/challenging to build that may be completely impractical, then I consider what I would actually need or find useful in survival. I also consider integrating my ideas into a ship. Great examples of a challenging, yet impractical builds are my robotic hands. No way you would need that, but a sample storage system for cataloguing planets may actually be useful.
Along the lines of giving you an idea for something useful: Is it possible you could create a scanner, like a radar using rails and triggers, that can output a depth value with decent resolution? Might be useful for robotics, blind flying experiments, and intelligent mining drones if you can pull it off.
EDIT: Reworded for clarity.
i have thought about a system like that before, using detection and plex doors to map the area around you, combining it into a miner though is something i didn't think of. sadly enough 2 things will mostlikly make this impossible. the first thing is that the detection thingys are not reliable and need a really strong signal to exualy notice something (from my experience using it). the second thing is that for the movement of this miner i would need take off burst, something not that hard to use, but this will only take care of 1 dymension, the Z dimension. if i try to rotate the burst it won't work like with weapons. i also tried docking a ship aiming upwards to take care of the Y dimension, this also failed because only the "host entity" is able to make movements. now i dont really need the X dimension on a planet, if the miner would go always forward, it should change lanes at the change of segments.
Make a missiles spammer that shoots 100 missiles per second.
this is already in existence and downloadable. someone did a great job on it, though i'm not sure if it was 100 per second, it's crazy fast.
Automated Mining Drones are cool.
You need storage fill in sensors and pushpulses.
if you figured out how to build the logics, you could send that ship to an asteroid or planet press start button and it will start to mine resources until there are no blocks left.
This thingy is quite useful and its medium difficult to build.
as you read from what i said to trekkerjoe, you could see i've been experementing on a automated mining drone. resulting in an failure, i've even suggested the option of side ways and up and down bursts, but they didn't respond to that.
There really is an issue of what all is important. Most weapons are better controlled by pilots in a ship or AI than logic. A lot of rail logic is difficult to justify outside of academics because simpler systems could do the job. Something I've been looking into a bit, but am having difficulty with is making a docking system to place ships in appropriate positions to optimize space while minimizing overlapping box dims.
don't really know something for this, if you really want least amount of overlapping the ships should be boxes. that said.... maybe put every dock in a box so that you can put every box tightly to eachother, though this will still only work for a set amount of ships or only 1 specific ship. if you make a ship shaped like a puzzle piece, you'd totaly be able to have minimum overlapping. in other words i don't really know, sorry.
thanks everyone for trying to help me, whenever you pop up with an idea, i'm open for it.
luckily, 2 hours after i posted the thread blackhawk came to me asking a shit load to do, he filled up my time, yesterday. hoping he has some new things for me today :P