(covers information from several alternate timelines)
The Intrepid-type escape pod was a type of escape pod used aboard Intrepid-class and Defiant-class starships in the late 24th century. In the event of a ship-wide catastrophe, the pods could be launched as a last resort to save the crew. Once deployed, the pods were vulnerable to attack or becoming engulfed in the destruction of the parent ship. As in other types of Starfleet escape craft, the pods were equipped with thrusters, providing some chance of fleeing the field of combat. However, without warp drive, survivors were reliant on larger ships for ultimate rescue.
Aboard Intrepid-class starships, the pods were stowed beneath individual hatches, which were raised in order for the pods to be launched. The pods could then return and be stowed again, if necessary.
In 2377, an escape pod was used by a modified hologram of Lieutenant Reginald Barclay while attempting to capture Seven of Nine for a group of Ferengi who were conspiring to steal her nanoprobes. (VOY: "Inside Man")
Later that year, escape pods were used as weapons. While trying to fend off a Quarren attack, The Doctor as the ECH ejected three escape pods which actually contained photon torpedoes. When the Quarren ships tractored them in, they were detonated, and the Quarren ships were disabled. (VOY: "Workforce, Part II")
In an alternate timeline, the crew of Voyager disbanded in escape pods, hoping to evade the Krenim Imperium in the smaller craft. The timeline ceased to exist with the destruction of the Krenim timeship. (VOY: "Year of Hell, Part II")
In 2374, following a disastrous attack on a Jem'Hadar battleship, the crew of the USS Valiant used these pods to escape the ship. (DS9: "Valiant") A year later, escape pods were used to flee a second Defiant-class starship, the prototype USS Defiant, upon its destruction at the hands of the Breen. (DS9: "The Changing Face of Evil")
Aboard Defiant-class starships, the pods were launched from specialized bays beneath retractable sections of hull plating. These sections were spaced about the ship, providing access for as many crew members as possible.
In the development of DS9: "Valiant", the usage of multiple Intrepid type escape pods was originally to have been a single shuttle, as envisioned by the series' writing staff. The idea of instead using some kind of escape pod then arose. "The Voyager lifepod CGI model already existed, so it became fairly convenient," recalled Visual Effects Supervisor David Stipes. Although the notion was at first only to use one of this type of escape pod, the decision to show a group of them was soon arrived at. "Dan Curry came up with the idea of the having the lifepods shot at [....] Dan went and talked with ['Valiant' writer] Ron Moore, the producer/writer, and everyone thought it [the whole plan] was a great idea," explained Stipes. (Cinefantastique, Vol. 30, No. 9/10, p. 57)
According to the Star Trek: Deep Space Nine Technical Manual, the USS Defiant carried twenty-six of these pods, which were six-person craft capable of sustaining survivors for up to eight months. Eight-person versions were also said to exist, although it is unclear whether these were supposed to have been seen on-screen. Both types were equipped with impulse microthrusters and emergency subspace comm systems.
There appears to be at least one phaser strip on the outer hull of the pod.
In the DS9-based computer game The Fallen, escape pods of this type were used aboard the Miranda-class USS Ulysses. They were also seen used aboard another Miranda-class vessel, USS Leonov, in the 2003 Ships of the Line calendar. Neither of these sources is considered canon.