How to spell SSTO correctly?

The correct spelling for "ssto" could actually be "STO" which stands for "Single-Stage-to-Orbit". Another suggestion could be "SSTO" which stands for "Single-Stage-to-Orbit" as well but with an additional "S" indicating "Spacecraft". It's important to clarify the context to determine the correct spelling.

• Sato

Putrefication

• nitrification
• petrifaction
• purification
• putrefaction
• putrification
• vitrification