Pre-Warp Impersonations: Starfleet Preserves the Prime Directive

' "" found , , and on a mission to investigate the presence of a Starfleet power signature on Dilmer III, a pre-warp planet with a startling time differential. Dr. T'Ana altered the three officers' features to resemble the local Dilmerians, which came in handy when they became trapped on Dilmer III for much longer than they had anticipated.

Whether superficially, chemically, or surgically, the time-honored tactic of modifying an away team's looks to blend in with a less-advanced society and avoid violating the has endured for over a millennium, from the days of Captain Jonathan Archer's NX-01 to Captain Michael Burnham's adventures aboard the U.S.S. Discovery-A.

Encountering the Akaali in 's ""

During Starfleet's initial foray into deep space, Captain Archer's Enterprise NX-01 came across the homeworld of the pre-industrial Akaali. T'Pol advised Archer that the Vulcans waited until a society developed warp travel to make first contact, but the captain opted to go to the surface rather than allow the opportunity for exploration to pass him by.

Dr. Phlox modified Archer, T'Pol, and Hoshi Sato's faces with Akaali characteristics, though Sato noted that the alterations felt somewhat itchy. The captain's curiosity paid off, as he soon uncovered a Malurian who had also been posing as an Akaali. The Malurian's covert antimatter reactor was poisoning the local population, prompting Archer to intervene and force the interloper to remove his equipment from the planet.

An Undercover Recovery in Star Trek: Enterprise's ""

Donning removable prosthetics to resemble another pre-warp population, Captain Archer led Hoshi Sato and Malcom Reed on a mission to study the politically volatile planet. Upon realizing that the security officer had accidentally left his communicator below, Archer and Reed returned to the surface to recover the device, only to be captured by one of the world's two main factions. Their captors initially believed them to be spies, though the humans' physiology indicated otherwise.

In order to prevent any cultural contamination, Archer claimed that they were genetically-enhanced soldiers being produced by the planet's other faction. The military intended to execute the Enterprise officers, but Charles "Trip" Tucker and Travis Mayweather swept in aboard a Suliban cell ship to rescue their comrades and retrieve all evidence of their imprisonment.

Caught by the Kiley in ' ""

Tasked with determining what happened to Commander Una Chin-Riley's first contact team at Kiley 279, Captain Christopher Pike and the U.S.S. Enterprise crew were surprised that sensors did not detect any interplanetary traffic or subspace communications when they arrived at the planet. With Kiley 279 lacking any signs of local space colonization, Spock deduced that the Kiley had not constructed a warp drive, but a warp bomb.

Concerned about how a pre-warp society, particularly one with two warring factions, could build such a bomb, Pike joined Spock and La'An Noonien-Singh to rendezvous with Nurse Christine Chapel, who administered injections which induced short-term physiological changes that allowed them to look like the Kiley. The Enterprise officers liberated their colleagues from the surface, where they encountered a stunning revelation. Kiley 279 was less than a light-year from the coordinates where the Federation had engaged Control's fleet! The Kiley observed the vessels' warp signatures via telescope and reverse engineered a matter/anti-matter reactor. Sadly, Starfleet had contaminated the world after all.

The Legend of Landru in 's ""

While investigating the loss of the starship Archon at Beta III, Hikaru Sulu beamed back to the U.S.S. Enterprise in a severely altered mental state. The Betans appeared similar to humans, but Captain James T. Kirk's landing party wore antiquated clothes in a bid to go unnoticed.

The Betans demonstrated strange behavior, and upon further research, Kirk discovered they had previously crafted advanced technology prior to regressing approximately 6,000 years before the Enterprise's arrival. A leader named Landru had emerged, rescuing the planet from a devastating war and convincing the Betans to embrace simpler times. Landru programmed a computer to carry on his peaceful work, but the machine had inadvertently stifled the society's creativity and progress. Fortunately, Kirk outwitted the computer and broke its hold over the community.

Meeting the Mintakans in 's ""

Although an anthropological team studied the Bronze Age-level Mintakans from the camouflage confines of a holographic duck blind, the outpost's malfunctioning reactor exposed a father-daughter duo to the Federation's presence on their world.

Disguised as Mintakans, William Riker and Deanna Troi traveled to the settlement to search for a missing scientist and gauge the extent of the cultural contamination. The Mintakans became increasingly convinced that a supernatural being known as "the Picard" was their overseer, so the captain elected to beam the Mintakan leader to the U.S.S. Enterprise-D and explain that he was a mere mortal. In the end, the other Mintakans only accepted the fact that the captain was not a god after he was wounded in a near-fatal incident.

A Malcorian Story in Star Trek: The Next Generation's ""

With the Malcorians on the cusp of achieving warp travel, Starfleet dispatched William T. Riker to the planet in an effort to coordinate the final details of first contact. Wounded as he tried to avoid a riot, Riker awoke in a Malcorian hospital.

Though his external features mirrored their own, the Malcorians did not take long to ascertain that Riker belonged to a different species. Fears and rumors ran rampant, and despite positive contact between Captain Picard and senior Malcorian officials, the planet's chancellor believed his citizens would not be prepared to greet visitors from other worlds with the warm reception they deserved. With this in mind, the Malcorians delayed their warp program indefinitely.

The Boraalan Breakout in Star Trek: The Next Generation's ""

When Boraal II was rendered uninhabitable, Federation observer Nikolai Rozhenko took it upon himself to save a small group of Boraalans from extinction. The foster brother of Worf, Nikolai violated the Prime Directive and concealed the survivors in a holodeck simulation as a way to prevent the Boraalans from finding out they had departed their world.

Left with no other option but to go along with Nikolai's plan, Captain Picard ordered Worf to pose as a Boraalan and help his brother shepherd them through the holoprogram as the U.S.S. Enterprise-D located a suitable home for the colony. The strategy prevailed, but one Boraalan learned the reality of the situation and decided to commit ritual suicide when faced with the decision to keep the truth from his people or leave them behind.

Homing in on the Barkonians in Star Trek: The Next Generation's ""

Assigned to track down an errant Federation probe before its radioactive fragments contaminated the biosphere on Barkon IV, Data experienced a power surge that overloaded his positronic matrix. Unable to recall his name or origin, Data was taken in by a Barkonian family and began to put together the pieces as a mysterious illness made its way through the community.

Data, or Jayden as he was known to the pre-industrial Barkonians, concocted a medicinal compound to neutralize the radioactive particles which had made the townspeople sick. Unfortunately, angry villagers struck him down as he released the treatment into the town well. Going undercover as Barkonians, Commander Riker and Dr. Crusher arrived to transport Data back to the ship and reactivate him.

A Photonic Family Man in 's ""

Much like the U.S.S. Cerritos' experience at Dilmer III, U.S.S. Voyager had its own brush with a planet enveloped by a powerful space-time differential. With Voyager ensnared by an eddy, centuries passed by on the world below as Captain Janeway's crew struggled to free their vessel. The starship became a fixture in local lore, and The Doctor embarked on an away mission to gather intelligence that might help Voyager break orbit.

B'Elanna Torres even gave the Emergency Medical Hologram access to his facial and epidermal parameters so he could instantly mimic the populace's appearance. A slight delay resulted in The Doctor getting stranded on the planet for over three years, a lengthy tenure during which he embedded himself in the pre-warp society, enjoyed romantic companionship, and — somehow — had a son!

The Rites of the Halem'nites in 's ""

On course for the next clue in the quest for the Progenitors' advanced technology, , where a Denobulan scientist had disguised a weather tower as a mountain in order to hide it from the planet's pre-warp inhabitants.

Posing as Halem'nites, Captain Burnham and Sylvia Tilly participated in the Journey of the Mother Compeer, a ritual race which was believed to please the gods. As Burnham diverted from the path to repair a camouflaged control panel that regulated the weather tower, Tilly endured a harrowing trial which brought her close to death. Saving Tilly required Burnham to reveal her true identity to the Halem'nite leader, and she promised to teach him how to maintain the Denobulan technology that safeguarded his society. Luckily, the ordeal also led Burnham and Tilly to the next Progenitor-centric clue!