There's propably not only one thing what makes ping high. What I have in my mind right now are:
1. Your internet/connection etc.
2. STS servers
3. Distance from you to STS servers
4. Amount of people playing at the time (too many players may make servers unstable)

So, if you have a apartment next to STS HQ, have extremely fast wifi with good connection, low amount players playing at the moment and STS servers are running good, you will have propably like 10-50 ping.