If you are looking for some different Sci Fi terrain then take a look at some of WorldWorks Games more recent releases. WorldWorks produce a large range of download and print terrain for Modern, Fantasy, Horror and Sci Fi gamers. Reduced by 60% on your printer their products can easily be utilised by 15mm Sci Fi buffs.
I know some of you already utilise the Modern 'Mayhem' porducts and a few, like me own Mars Station. If you are a fan of the Xbox game Mass Effect, then take a look at the newly released Codename Titan set.
There's just something about Codename Titan that reminds me of the corridors of the less than salubrious OMEGA space station in Mass Effect 2. This grungy, utilitarian terrain can also be used to create external settings, such as the streets of a heavily industrial world or asteroid mining city. But perhaps Mass Effect's not your thing and you prefer Gears of War instead?
Then take a look at both WorldsWorks Fantasy and Horror products in addition to the Sci Fi offerings. There's plenty of terrain for recreating the action from Gears 1 & 2. Shelldrake Manor could easily proxy for Adam Fenix's home.
The Himmelveil Streets set pictured above offers not just a chance to game Cogs of War but also has a strong flavour of New Mecca on Helion Prime from Chronicles of Riddick. Offering the gamer an old world whose architecture isn't for once Gothic.
Mars Station has been replaced on my 15mm tabletop by GZG and Critical Mass Games' products but still does stirling work for 28mm Sci Fi skirmishes. Which remind me that I must buy Antenociti's 28's. Beautiful high Sci Fi miniatures in the Mass Effect style. If only they did the GOT Troopers in 15! Some great poses too!
Mars Station comes with interiors plus control panels etc. Again, a 60% scaling reduction will bring your outpost to life and being printable it can be as large as you like.
I was never a fan of gaming tiles. I liked all my terrain to be 3-D but I've mellowed under the constant bombardment from both Masterchef and Alternative's Armies' Firefight 2.0.
All the above game come with 'tiles' grided and ungridded. The Himmelveil Streets tiles are magnificent, Masr Station allows you to build not only a 'red planet' gaming mat but the canyons you see in the photo as well!
To sum up. Plenty of opportunity and potential to produce staggering 2D or 3D scalable terrain to meet your gaming needs for a small initial outlay and a little effort.