If your planets a FL SPH file then resizing them is a breeze as they don't have a mesh as such. Open it with UTF-Edit and expand the Sphere node, you'll see M0,M1,M2,M3,M4,M5 these are the 6 sides of your planet, M6 is the atmosphere, Radius is the size of the planet. Sides is like the material count in a mat file it's a check sum to make sure nobody's screwed up.
Radius is the one you want highlight it the set the "interpret data" to float, highlight it then click "edit", the simple data window will have something like this.
1000 .000000
0.000000
Change the bit in
Bold to whatever you want, I have one at 10,000 but for you set it to between 50000 and 100000 that way it'll take up half a system, after you've done that click the "update" button and save your SPH file.
Coding it into the solararch.ini is the same as coding any other planet.
nickname = bryans_test_10000
ids_name = 60203
ids_info = 60204
type = PLANET
DA_archetype = solar\planets\custom\bryans_test_10000.sph
material_library = solar\planets\custom\bryans_test1.txm
material_library = solar\planets\planet_earthgaiacap.txm
material_library = solar\planets\detailmaps\detailmap_rock01.txm
material_library = solar\planets\atmosphere.txm
material_library = solar\planets\custom\bryans_test.mat
mass = 1000000
solar_radius = 10000 <<--has to be the same size as the SPH's radius node
shape_name = NNM_SM_MEDIUM_FOREST_MOON
Adding it to a system is the same
nickname = Ss01_05
ids_name = 459093
pos = -90909, 0, 134770
rotate = 0, 0, 0
archetype = bryans_test_10000
ids_info = 65765
spin = 0, 0.02, 0
atmosphere_range = 10200
burn_color = 255, 222, 160
Ambient = 35, 35, 45
zone
nickname = Ss01_05_death
pos = -90909, 0, 134770
shape = SPHERE
size = 10100
damage = 30000000
sort = 99.500000
density = 0
relief_time = 0
You can even get a death zone for the outside, then it's a case of stick a nebula zone on the inside and add an exclusion to it.
**shuffles of with a new headache**