Space Shuttle Discovery March 9, having spent a cumulative total of almost a full year in space. "Discovery" performed both research and International Space Station (ISS) assembly missions. It also carried the Hubble Space Telescope into orbit. "Discovery" was the first operational shuttle to be retired, followed by "Endeavour" and then "Atlantis". The name "Discovery" was chosen to carry on a tradition based on ships of exploration, primarily , one of the ships commanded by Captain James Cook during his third and final major voyage from 1776 to 1779, and Henry Hudson's , which was used in 1610–1611 to explore Hudson Bay and
Hubble Space Telescope shroud of multi-layer insulation keeps the temperature within the telescope stable and surrounds a light aluminum shell in which the telescope and instruments sit. Within the shell, a graphite-epoxy frame keeps the working parts of the telescope firmly aligned. Because graphite composites are hygroscopic, there was a risk that water vapor absorbed by the truss while in Lockheed's clean room would later be expressed in the vacuum of space; resulting in the telescope's instruments being covered by ice. To reduce that risk, a nitrogen gas purge was performed before launching the telescope into space. While construction of the spacecraft in