Phasing cloaking device

In 2358, Starfleet Intelligence developed an interphase cloaking device that, unlike standard cloaking devices (which rendered starships invisible to sensors and direct eyesight of most humanoids), could permit a starship to travel through solid matter and high-energy fields. Though the Treaty of Algeron between the Romulan Star Empire and the Federation forbade the latter from developing cloaking devices, advocates of its development used the USS Pegasus as a testbed for the interphase cloak. Despite initially successful tests, the device malfunctioned, merging Pegasus with an asteroid as a result of the cloak's functional properties, making the ship irretrievable. 

[[USS Baldwin|USS ''Baldwin'']]
In 2374, the USS Baldwin (NCC-2013) was discovered in orbit of Aloran IV, equipped with a cloaking device. Starfleet and the Romulans subsequently agreed that the section of the treaty barring the Federation from using cloaking devices is unenforceable, and the interphase cloak was deployed aboard Baldwin. (: "Meet the Baldwin")

Field testing continued aboard Baldwin. The interphase generator could be switched on or off as needed. An attack by continuous weapons fire can cause the generator to deactivate involuntarily, leaving the affected ship vulnerable but still cloaked. A scan with proper temporal variance can make a phased ship detectable. Similar modifications to the weapons can make a phased ship vulnerable to attack. However, a simple retuning of the cloak can counteract the effects. Scanning for a phased ship without knowing the proper variance is limited to 6000 kilometers.

In 2383, another interphase cloak was installed onto the USS Phoenix-X (NCC-75948) at Regula I. The cloak was found to be sabotaged, thus overloading the ship's external sensors during a phase-test inside the Regula planetoid. To make matters worse, the clusters of ore within the rock was found to be highly reactive to the effects of Genesis' protomatter, a century earlier; placing any phased ship in danger of destabilizing if coming in contact with it. With the help of Erik Pressman, the Phoenix-X was able to reverse the sabotage to the cloak and leave the planetoid.