Hubble Space Telescope (SCRS). , the Trump Administration is considering a proposal by the Sierra Nevada Corporation to use a manned version of its Dream Chaser spacecraft to service "Hubble" some time in the 2020s both as a continuation of its scientific capabilities and as insurance against any malfunctions in the to-be-launched James Webb Space Telescope. There is no direct replacement to Hubble as an ultraviolet and visible light space telescope, because near-term space telescopes do not duplicate Hubble's wavelength coverage (near-ultraviolet to near-infrared wavelengths), instead concentrating on the farther infrared bands. These bands are preferred for studying high redshift and low-temperature objects,
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