Laika was the name of the first Soviet dog into space, and it is quite obvious that [Rockman.EXE] Laika was named after it.
However, the kanji for his name is written
and would be romanized as Ra-i-ka. And his English dub name is Raika.
Laika is most appropriate because he is from Sharo (Capcom's version of the Soviet Union), not Japan, and he is definetly not English/ American/Canadian.
And besides, if I called him Raika, all the "Laika" fangirls would be out there to stab me in my sleep. x.x