R.O.V.E.R.S.
Robotic
Observation
Virtual-enhanced
Extra-vehicular
Recording
System
In the early years of spaceflight, UESPA's Starfleet forces quickly learned that captains and their crews had trouble assimilating data from external feeds during stressful combat situations due to the lack of audio-visual data. Ships and their weapons were silent, energy beams were invisible without a medium to travel through, explosions lacked the necessary large flames that conveyed an immediate threat without oxygen to act as a combustion source.
Computerized data provided the answers but it lacked the swiftness of simply observing the situation with your own eyes and ears and instantly responding: Visually tracking an energy beam to its source, responding to the severity of an explosion by avoiding the blast wave or scrambling emergency personnel to the area, knowing an enemy is firing at you by the sound of their torpedoes, outmaneuvering a ship because you can hear their engines straining in a turn.
Thus, the R.O.V.E.R.S. program was born. Using the very best in special effects wizardry of the fledgling holographic digital film industry of the day, ROVERS were small independently operating spherical robotic probes about the size of a softball launched from a vessel in anticipation of a coming battle or an encounter with a vessel or an anomaly of some type. The ship's main computer launches them automatically without any human interaction needed and does it on the instant of detecting a threat level incident or something of exploratory value.
They remain linked with the ship's main computer at all times and it acts as their central brain. Their one and only task is to provide data in the full EM spectrum on their home vessel and any nearby vessels / anomalies / objects, etc. They have limited thruster capability but are cheap and easy to produce and are simply left behind if the ship moves out of the area and are replaced by new ones. They can only be accessed by Starfleet fractal encryption sequences and are equipped with simple self-destruct mechanisms if tampered with to prevent the enemy from acquiring their data. (Though some crazy rumors that have Starfleet Command deeply worried have recently surfaced that the data can be accessed through late 20th and early 21st century television sets for unknown reasons likely related to a temporal anomaly of some sort. j/k)
The devices serve many purposes:
- Convey pseudo-auditory data to the crew of a starship - revving and turning engines, explosions, beam weapons, screams of a dying spaceborne lifeform, crashing asteroids, etc. None of these are real of course, they are simply extrapolated from subspace EM sensors and using intuitive programming the computer guesses what they should sound like if they happened in an M-Class atmosphere similar to that aboard the ship.
- Illuminate enemy energy beams so they can be tracked back to their source. Though at short ranges the beam has already invisibly hit your vessel before the projection is overlayed in most cases (except at longer ranges where the subspace FTL sensors can overlay the data before the sublight particle beam or light speed laser beam arrives at its target), in terms of human observation and response times it appears instantaneous.
- Overlay the impression of visible blast waves and blazing fires from large explosions calculated to appear more threatening based on the computers intuitive threat level estimates. These serve to visibly indicate weak points on your own and enemy vessels to you by showing burning flames. In case of a large blast wave like that of the Klingon moon Praxis where there is no time to escape, the computer will display the wavefront along the ship's axis of flight even though it is actually a spherical wave.
- Act as a "Black Box" flight data recorder for a destroyed vessel. This happened in the case of the NCC-1701 Enterprise when it was destroyed above the Genesis Planet via self-destruct. External ROVERS recorded the whole incident so it could be replayed before the Federation Council once they were recovered. Unfortunately since the ROVERS have no more than a very short range thruster system they can't seek out Starfleet vessels, but their onboard encrypted transponders do make them easy to find in most cases.
ROVERS were even modified for use inside the ships themselves. They float about casually filming every aspect of onboard life - never attracting attention as they hover up in the shadows - specifically designed to remain out of sight so as not to bother the crew. Every important room on a ship became equipped with at least one to film what was going on in-concert with pre-existing fixed position 360 degree view cameras in the walls installed during the "Wall-Eye" Program of 2250 for the new NX-01 Enterprise. They were put to good use by Admiral Kirk and Sarek while investigating whom Spock left his Katra with after the Khan Incident of 2285.
Future endeavors in the field seek to create "Virtual Viewers" using downscaled technology borrowed from the MIDAS and ARGUS Arrays which use targeted micro-wormholes which allow sensor data to flow both ways between them. Soon it will be possible to dial-up a location and view it without any actual need for hardware on-site. This will bring a revolution in espionage, flight data recording, and communications ability.
As always, Starfleet heeds the advice of its personnel about the dangers of such technology creating a "Big Brother" mentality. A favorite Latin phrase employed by those opposed to the overuse of the internal ROVERS devices is
"Sed quis custodiet ipsos custodes?" or "Who watches the watchmen?" They are often reminded of the fact that Starfleet is not a democracy, it simply protects democracy, and that they are serving on a military vessel that could quite easily wipe out entire planets or even stars with modern weapons and that extra security measures are justified as long as they are not abused.
The typical response by Starfleet is to invoke Section 31 - Paragraph 1 of the Federation Charter:
"Starfleet personnel must consider it their most sacred duty to take any and all action deemed necessary to defend the Federation first and foremost against all enemies, foreign and domestic, regardless of physical or ethical cost or personal and professional risk."
The purpose of this article was to find an explanation for certain strange occurrences in Trek such as:
- The NCC-1701 being filmed from the outside as it exploded in "The Search for Spock" - a recording which was later shown to the Federation Council. This is after the Bird of Prey flew away to avoid the explosion mind you, so that camera angle couldn't have come from it.
- Epsilon 9 station still sending telemetry and video data to Earth after it had been "digitized" by V'ger and disappeared completely in "The Motion Picture".
- The video feed from the Neutral Zone asteroid base in TOS: "Balance of Terror" still showing up after it had been destroyed.
- The computer having a shot of Spock removing Scotty's gloves in "The Wrath of Khan" from a perspective about one foot off the floor in an open walkway section of engineering. Granted, and internal camera might have been able to capture that feed, but it was an odd angle for an internal security monitor.
http://canonfodder.ex-astris-scientia.org/index.php?Science_&_Technology:R.O.V.E.R.S.
Although, I suspect that nothing like that was on the minds of the writers of the time, or it would have been at least explained in a short line of dialogue 
