Space Station's Robotic Cargo Ship Fleet (A Photo Guide)

Space Station Destination

The International Space Station is the largest structure ever built in space. The outpost, the product of 15 countries and five different space agencies, carries a an international crew of six people when fully staffed. But to support that crew, NASA and its partners rely on robotic cargo ships to ferry food, supplies and other vital gear to asttronauts. Here's a look at the robot delivery ships that make those important supply runs:

Russia's Progress

Russia's Progress ships are the workhorses of the cargo freighter fleet. More than 30 of these expendable vehicles have supplied the ISS.

Russia's Progress Cargo Spacecraft

This infographic profile of the Progress cargo ship used to service the International Space Station.

Russia's Progress

Here, the unmanned Russian Progress 42 cargo ship is seen by a video camera on the exterior of the International Space Station just before docking on April 29, 2011.

Europe's ATV

The European Space Agency's "Edoardo Amaldi" Automated Transfer Vehicle-3 (ATV-3) is one of a suite of robotic spacecraft that deliver goods to the International Space Station. Europe's ATV vehicles are huge, large enough to fit a London double-decker bus inside.

Europe's ATV

In this photo, the Automated Transfer Vehicle-3 (ATV-3) approaches the International Space Station on March 28, 2012.

Japan's HTV

Japan's HTV vehicle is another robotic cargo ship that ferries supplies to the space station. Here, it is shown just before astronauts grapple it on Jan. 27, 2011. Japan's HTV vehicles have the unique ability to carry cargo inside a pressurized section (for astronaut use) and in a exterior compartment for external use.

Japan's HTV

Backdropped by Earth's horizon and the blackness of space, the first unpiloted Japanese H-2 Transfer Vehicle (HTV) approaches the International Space Station on Sept. 17, 2009.

SpaceX's Dragon

Dragon is the only reusable member of the cargo freighter fleet. This capsule is built by private company SpaceX (Space Exploration Technologies), and began making delivery runs to the station for NASA in 2012.

SpaceX's Dragon

This graphic illustrates the design of SpaceX's Dragon, which is meant to carry people eventually.

Orbital Sciences' Cygnus

Orbital Sciences Corp. is another private company flying uncrewed supply ships for NASA. The spacecraft is built by Northrop Grumman Innovation Systems (formerly Orbital Sciences and Orbital ATK) and made its first trip to the space station in October 2013.