Sky trooper is called as is “sky trooper” in Japanese. It’s not translated into Japanese words and is written in Katakana letters as a Japanglish word. Here’s the spelling.
The Japanese language doesn’t have an R sound, and the pronunciation sounds like SU KA I TO LŪ PĀ.
Can’t you write it in Kanji letters?
You can if you want. There’s no Japanese word that is exactly the same as sky trooper, but I think the one for “air cavalry” or “airman” is the closest considering the meanings.
Here’s the Japanese word KŪCHŪKIHEI, meaning air cavalry.
KŪ = air, sky
CHŪ = in the middle of
KIHEI = trooper, cavalry
This one is KŌKŪHEI, meaning an airman.
KŌKŪ = aviation, flying, aerial
HEI = soldier