My apologies if I took longer than you would have liked (I don't put off the sketching part, but I am terrible with procrastinating when it comes to scanning stuff), but here is what I came up with so far:
http://www.flickr.com/photos/40445677@N06/5995454690/in/photostream/
Also, it seems much of it scanned lighter than I would have liked. If you have a hard time seeing the shapes and lines, I can go back over everything with darker pencils, and scan it again.
I was thinking that Starfleet didn't start making exploration vessels until after the Dominion War, so I figure this is after the Dominion War, but these ships are like the Legacy class: they were first launched before the Luna class, so they have lower registries (no earlier then in the 76000-range, and no later than the 79000-range, though I would recommend using registries in the 77000 or 78000-range, because I believe that there are many in this range that are unused).
I designed her with a primary hull a rounded triangular shape, somewhere between that of the Intrepid class and Nova class, and with rounded edges, similar to the Galaxy and Legacy class. This is of course because of my taste for sleekness. The over all feel I was trying to convey was something similar to the Intrepid class, but sleeker and with a somewhat pointy nose, more like the Hades class,
a design that I found on the internet. The sides of the primary hull are thicker to contain dedicated scientific sensor equipment, and the inner part of the edges curve downward when the meet the inner part of the secondary hull.
I also included raised sections similar to the Luna class, and the bridge is safely nestled in between them. If you would prefer to go without them, then another idea I had, but didn't have enough room on my paper to sketch out, was a primary section more along the lines of the aforementioned Hades class.
The back of the primary hull has a raised section like the Miranda class, and your Explorer class, which has the shuttlebays. Closeby are four impulse drives, similar to the Explorer class. In this case, I have experimented with the idea of giving her a hull separation, similar to how the original could separate her saucer from the engineering section, which I felt would be a fitting development for her evolution, and was a perfect way of referring to the quad impulse drive of the original, as well as using them to their full advantage.
The two hulls transition similar to the Galaxy class, and I have imagined her as having a small or semi-neck, similar to the Arrogant class and Frontier class, since most ships by this time only have short necks, if any at all.
I would imagine the nacelles could share elements from both the Intrepid class, and ships like the Sovereign and Nova class. I have even speculated that design elements from the Luna class are not out of the question, though I haven't really gone into sketching much out in this regard.
Finally, there are the torpedo launchers and sensor pod. One idea that I had was simply going with the design arrangement the Explorer class uses, while another idea I had was using a sensor platform using design elements in between that of the Nebula and Luna classes. The four torpedo launchers in this case would be mounted in the sensor platform, where they could also act as probe launchers as necessary.
Oh yeah, I almost forgot about the primary deflector! The primary deflector is mounted underneath the primary hull, similar to the Akira class, and like the Explorer class as well. She shamelessly takes design cues from the Akira's deflector housing, but I envision it as slimmer. In front of the main deflector, I envisioned her as having a pair of torpedo launchers, so that both sections could have that ability, if necessary. And the secondary hull has a deflector array on the nose as well.
Anyways, I hope that you like what I've come up with so far, and if you would like me to do some more sketches (or further refine the current ones), I'd be happy to do so.
