Graham Kennedy wrote:There's nothing to say that this kind of thing isn't happening. Notice that in Tomorrow is Yesterday the ship's nav deflectors were enough to prevent it being detected on any radar Earth had in the 1960s. In Future's End Voyager could avoid 1990s radar by a simple shield modulation.
It would be perfectly reasonable to suppose that the NX design was very stealthy by the standards of the day, such that a merchant ship would have great trouble spotting or targeting it. Or that the Constitution would likewise be very hard for an NX to see on sensors, whilst the Connie would see an NX from a long ways off.
What they didn't have was the particular "cloak" which functioned by bending light around the ship to make it actually invisible to the naked eye. But hell, nobody in the 22nd century had that until Berman and Braga mucked up the continuity.
Tomorrow is Yesterday - TOS starship (and science) vs 1960s technology.
Future's End - TNG Voyager vs 1990's technology.
I'd argue that the 2-4 centuries of tech advancement did more to protect vs local radar instead of the specific technology. As to NX-01 being stealthy vs civilian ships, that is the inherent difference between civilian and military ships. The NX would use its far better sensors and any passive signature stealthing to track the cargo ship, while the cargo ship would use its basic sensors to avoid hitting anything in their path, and track stuff that is very nearby.
But having a cloak that is worthless vs other races would be a nice idea, unfortunately, I'd expect the Vulcans to point out each cloak ship using their sensors. "Yes, you are trying to develop a cloaked ship. However the sensors we are using to track it are fairly common. You really should focus on building a more reliable ship, rather than trying to go for poor stealth attempts."
Of course, dropping attempts to make cloaking vessels means that Starfleet can focus more of its efforts on science and sensor technology, and its ship hulls don't have to include cloak capability as a compromise. This makes them a bit tougher than a cloak-capable hull, and lets Starfleet handle slightly bigger opponents than others would expect.