This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
The Nomad MK-15c (NSSDC ID: 2002-045b) space probe was a Nomad Program spacecraft that was in service in the early 21st century. Dr. Jackson Roykirk designed the probe with two goals in mind: to create a probe that could function as a perfect thinking machine capable of independent logic and that could seek out new lifeforms in interstellar space.
In 2005, Nomad was damaged by a meteoroid and lost contact with Earth, wandering without purpose. It later encountered an alien probe called Tan Ru in deep space. The two units merged, resulting in a powerful new construct with faulty programming, which sought to destroy anything that was perceived as imperfect; a condition that it evidently applied to any organic living being.
Nomad was eventually discovered by the USS Enterprise in 2267, shortly after it wiped out four billion inhabitants of the Malurian system. Originally deeming the Enterprise to be as imperfect as the Malurians, it opened fire on the vessel, nearly destroying it. It halted its attack when Captain James T. Kirk hailed the probe and introduced himself, confusing Captain Kirk for Dr. Roykirk.
Upon coming aboard the Enterprise, Nomad found the crew to be imperfect and wiped out the memory of Lieutenant Uhura as well as killing Montgomery Scott. Fortunately for Scotty, Nomad was able to "repair" him back to life on the orders of Kirk. Using the ship's star charts, Nomad was able to fix coordinates on Earth and planned to return. Kirk was concerned that if Nomad returned to Earth and found it to be populated with imperfect lifeforms, it would sterilize the planet. Captain Kirk managed to convince the probe that it was imperfect because it had mistaken Kirk for Roykirk, its creator. This led Nomad to violently self-destruct, though Kirk was able to beam it out into space before it did so. (TOS: "The Changeling")
Nomad revealed a number of advanced capabilities during the encounter. It could travel at warp speed. It fired energy bolts approximately equivalent to ninety of the era's photon torpedoes, that traveled at approximately warp 15 and could track a starship. Its own defensive screens could entirely absorb the energy of a photon torpedo the Enterprise fired at it, despite its small size. They were also entirely opaque to sensor signals. Its communications equipment could absorb data from the Enterprise computers far faster than their maximum transmission rate, an act that damaged the computer interface. It could drain all knowledge from a living being. It successfully repaired Montgomery Scott after contact with its defensive screens killed him, in essence restoring him from death. To do this, it required only a few moments to study tapes of his "structure." It also effected mechanical changes to the Enterprise propulsion system that improved its efficiency (to the point that the power of the engines threatened the structure of the ship). It was able to both "repair" Scott and "upgrade" the engines without making physical contact. It was also able to fire red beams of energy, which disintegrated anything they hit.
- Primary power system
- Magnetohydodynamic vernier-pulse
- Selective amplifier screen
- Regenerative mode emulsifier
- Data assimilation digital encoder
- Tracking screen and coupler prediction scanner
- Sperographic analysis computer
- Acquisition sensor
- Computer databanks recall and transmition
Nomad was voiced by Vic Perrin.
The Nomad prop was designed by Matt Jefferies and built by Jim Rugg and Irving Feinberg, the former moving and operating it via different methods. In fact, three Nomad props were built, each of them designed for different purposes.
Pieces of Nomad showed up again in the Romulan cloaking device in TOS: "The Enterprise Incident" and Flint's M-4 robot in TOS: "Requiem for Methuselah". The prop for Nomad's head was placed atop Sargon's storage vessel from TOS: "Return to Tomorrow" in order to create the Romulan cloaking device.
Among the in-jokes that appeared on the engineering cutaway of the USS Enterprise-D was an image of Nomad located where the ship's launch probes were supposed to be.
The model prop used for Mayweather's quarters in ENT: "Dead Stop" was created by Paul M. Newitt.  Newitt would later be asked to create the Nomad model prop for PIC: "Two of One", with just a twenty-day construction window.