Travelling the stars is a lot more fun when you have engineers who can turn rocks into replicators and scientists who come up with some crazy ideas on a whim and bring some brand new tech into creation to solve this weeks problem. But sometimes you have to wonder what happens to the inventions that didn’t last the week….

Borg Again
Once upon a time, Neelix died. Then Seven came along, casually unstuffed some Borg probes in him and suddenly he’s back to life again. Mortal Coil is an episode that focuses on Neelix’s belief and psychological after effects of being dead, even if just briefly, only to experience nothing but his revival. It’s a common story throughout all genre’s of TV. It’s just this time there were nanoprobes to speed up the ‘coming back to life’ part.
Seven’s nanoprobes were a catch all for any solution in Voyager and even if they were just a narrative cheat, you’d think using nanoprobes to raise the dead, it might be a technology worth bringing up again. Alas….

TR-116
Introduced on Deep Space Nine, the TR-116 was a prototype weapon that went back a few generations to include physical rounds instead of nadion particles to strike a target. Designed as a contingency where radiation or dampening fields would nullify a phaser, it was left as a prototype as regenerative phasers were the preferred path of research. It was all but forgotten about until a Vulcan science officer replicated one of his own, modifying it with a micro-transporter so that when fired the bullet could be transported to a target far, far away.
Sure, it’s a modification made by a serial killer and was the perfect weapon for assassination. So maybe the files were locked behind some heavy restrictions. But surely a long-range sniper rifle hidden from the enemy would have came in handy when trying to avoid the slaughter of your officers in ground combat against the Jem’Hadar.

Advanced Cloak
The rules for cloaking devices seem fairly solid, but over various era’s we’ve seen the technology gain a few advances that were dropped or forgotten quickly. In the Undiscovered Country the Klingons developed a ship that could fire when cloaked – a concept through to be impossible due to the immense power requirements. Yet this would never again be replicated, even with the overpowered Defiant and it’s leased Romulan cloak.
Further advances were made in the 24th century with the USS Pegasus using Romulan tech to build an illegal phase cloak in a failed experiment, and the Romulans had their own version in development that could turn people invisible while putting them out of phase with reality enough to pass through objects. Despite the leaps in advancement, none of the variants of upgrades would appear again leaving the cloaking device a simple but limited tool.

Holo Comms
Another advancement on Deep Space Nine came with the holo-communicator. A device that allowed direct projection of another person for face to face interaction instead of through a viewscreen. Conveniently the Defiant had one installed just in time for Sisko to have direct interaction to Starfleet turncoat Michael Eddington and then suddenly, as if it was just an episode specific MCGuffin, it vanished.
Discovery and Picard both dipped back into the idea, the most notable being Admiral Anderson dropping into the Shenzhou before the Battle of the Binary Stars, but the late TNG era never seemed to delve into the idea again with any depth.

The Barclay Drive.
Influenced by an alien probe, Reg Barclay became a genius for a day and built a new type of warp drive that could get a starship 30,000 light years by the time you finished this sentence. It was a huge technological leap and even though they managed to put Reg back to normal in the end, they still had the new warp drive which was never seen again.
It seems to be a recurring theme with the technology. Transwarp has had it’s moments from the original Excelsior engine to Tom Paris’ experiments. We’ve had slipstream, Spoke drives and protostars all pull in higher speeds than traditional warp. But for some reason or another it’t not until the 32nd century that Starfleet opts to abandon Zephram Cochrane’s original design. Even then it looks like it’s still around for Academy.
