-> It can come close though. Remember that for 100% sunlight, it should not be  
-> polar orbit, but an orbit perpendicular to the ecliptic.... 
  
Or maybe not even that. Yesterday, I calculated that the ISS would see 
the sun when about 1/20 of the orbital circumference beyond the 
terminator on the ground. So that's about 18 degrees. So the orbit 
could be inclined as much as 18 degrees away from the perpendicular to 
the earth-sun line and still have the station in continuous sunlight. 
If, as someone said, the orbit is actually inclined at about 52 degrees 
to the equator, and since the earth's axis is tilted at 23.5 degrees, 
the ISS's orbit might be tilted as much as about 75 degrees from the 
ecliptic, i.e. only 15 degrees from being perpendicular to it. 15 is 
less than 18, so, it seems, it *can* happen when things are aligned 
right that the station can receive continuous sunlight for a while, 
until precession alters the alignment. 
  
                        dow 
--- Platinum Xpress/Win/WINServer v3.0pr5