Maintenance pod

A maintenance pod was a type of small-craft used by the Federation Starfleet in the late-24th century. The pods were roughly spherical in design, featuring a large window around the front of the vessel through which the two man crew could observe their surroundings. The fore of the vehicle also featured a mechanical arm, called the servograsp for interaction with objects outside of the ship. 

History
In 2368 Commander William T. Riker and Lieutenant Commander Data of the USS Enterprise (NCC-1701-D) used one of Daystrom One's maintenance pod's to explore the facility's holographic tesseract archive and try and diagnose why the archive's A.I. systems had become unresponsive. While travelling to the central A.I. hub they found their route blocked by an unusual diamond structure not native to the archive; Using their pod's servograsp they attempted to probe the alien structure, which reacted explosively, severing the armature. Once Riker and Data had recovered they continued into the archive, and quickly encountered more of the explosive devices and soon found themselves under attack by two alien vechiles (who would later be found to be Romulans) which attempted to lock the pod in a tractor beam. Riker had Data bring the craft close into the Romulan vehicles and channel power from the pod's electrical systems into damaged servograsp which they in turn rammed into the Romulan's tractor emitters causing a violent feedback. With one of the Romulans disabled Riker and Data headed for the exit at the pod's best speed, but were pursued by the other vehicle which attempted to shoot them down with a disruptor. With the exit still minutes away Riker and Data decided to use the pod as a bumper car and rammed the other Romulan vehicle into the archive's transmission beams, damaging its propulsion system and allowing the pod to get away and call for backup. 

By 2387 the USS Enterprise (NCC-1701-E) had a compliment of maintenance pods. That year three of the Enterprise's pods were used to assist in repairs to the Romulan mining vessel Narada following an attack by Reman vessels.