A mother ship, mothership or mother-ship is a large vehicle that leads, serves, or carries other smaller vehicles. A mother ship may be a maritime ship, aircraft, or spacecraft.
Examples include bombers converted to carry experimental aircraft to altitudes where they can conduct their research (such as the B-52 carrying the X-15), or ships that carry small submarines to an area of ocean to be explored (such as the Atlantis II carrying the Alvin).
A mother ship may also be used to recover smaller craft, or go its own way after releasing them.
A smaller vessel serving or caring for larger craft is usually called a tender.
In many Asian languages, such as Chinese, Japanese, Korean and Indonesian, the word mothership (, 母艦, 모함, Kapal induk, literally "mother" + "(war)ship") typically refers to an aircraft carrier, which is translated as "aircraft/aviation mothership" (, 航空母艦, 항공모함, Kapal induk pesawat udara).
During World War II, the German Type XIV submarine or Milchkuh (Milk cow) was a type of large submarine used to resupply the U-boats.
Mother ships can carry small submersibles and submarines to an area of ocean to be explored (such as the Atlantis II carrying the Alvin).
Somali pirates use mother ships to extend their reach in the Indian Ocean.
In aviation, motherships have been used in the airborne aircraft carrier, air launch and captive carry roles. Some large long-range aircraft act as motherships to parasite aircraft. A mothership may also form the larger component of a composite aircraft.
Airborne aircraft carrier
During the age of the great airships, the United States built two rigid airships, and , with onboard hangars able to house a number of Curtiss F9C Sparrowhawk biplane fighters. These airborne aircraft carriers operated successfully for several years. These airships utilized an internal hangar bay using a "trapeze" to hold the aircraft.
Air launch
In the air launch role, a large carrier aircraft or mother ship carries a smaller payload aircraft to a launch point and then releases it.