I'm using the Kassae Space Map as my template, and I'm placing Reach Marker objectives. On the first of them, I noticed the default size was 10 km. As I wanted to make this easy to detect, I actually increased the radius to 20 km, and placed the marker atop a small Federation Satellite 2 I had placed.

In running the mission, the waypoint/active area is actually smaller than the satellite itself. I had to crash into it to get the next part of the mission to activate.

I set a second Reach Marker elsewhere -- this time not on top of anything. I didn't change the default size of the waypoint at all. The practical effect was the same -- it was tiny, and because I didn't have a physical object out there indicating it, I couldn't even find it with my ship.

The map shows a circle around a reach marker, indicating the activation radius.

I had to crank it up to about 100km to make sure it got past the asteroid base I put it inside.

I presume the marker is a sphere, not a circle?

If you select the reach marker, there are options to customize in the center.

"Volume" is the variable that increases or decreases the size of the reach objective. In space, this needs to be very large.

The default is 10km, which makes sense on ground maps. If you use them on a space map, then you need to increase the radius. I think this way is much easier than scaling the radius down a place marker that would spawn planet size on a ground map.

I've passed on a request to improve how Markers / Volumes feel in space. I can't give an ETA on when you may see a change, though. Darren and Kirkfat's suggestions are definitely valid workarounds in the meantime.

Gotcha, and excellent! I guess I'd gotten it in my head that 10 km = firing range in space, which was plenty of distance.

Modifying that volume to increase the size of the marker does wonders.

You can use it for scavenger hunt-type missions too, to ensure the player is actually looking at the object instead of just within 10 KM.