By the numbers: the Gravitas Dock Barge

Engineers love numbers, so here they are for the Gravitas Dock Barge. This Orbital construction barge packs a lot into a 340 m airframe.

Flight deck: 3 seats for pilots, with bunks for a full complement of 26. Payload capacity: 18,000 tonnes.

Propulsion: Xenon ion propellant, with consumption of roughly 8 tonnes per 100 AU. That supports an endurance of 6 AU and a sprint velocity of 45 km/s.

First flight: December 2179. Commissioning fee: from ₡330 million.