Apollo's hand exerting pressure on the hull of the Enterprise
GSC (or grams per square centimeter) was a unit of measure for pressure, equal to 0.001 KSC or roughly 1 millibar.
- Apollo's hand was capable of creating over 1,000 GSC of external pressure on the hull of the USS Enterprise. Above 1,000 GSC, and the systems aboard a Constitution-class start to become critical. (TOS: "Who Mourns for Adonais?")
Klingon Raptor-class being crushed by external pressure exceeding 15,000 GSC
- A Klingon Raptor-class warship was capable of withstanding atmospheric pressure of 15,000 GSC, or that found in a Class 9 gas giant approximately 2 kilometers in its atmosphere. That pressure was also well within the tolerance of a 22nd century Earth Starfleet shuttlepod. (ENT: "Sleeping Dogs")
- Defiant-class starships were capable of withstanding a hull pressure exceeding 9,000,000 GSC. (DS9: "Starship Down")