Advanced Technology Large-Aperture Space Telescope
The Advanced Technology Large-Aperture Space Telescope (ATLAST) is an 8 to 16.8-meter UV-optical-NIR space telescope proposed by Space Telescope Science Institute, the science operations center for the Hubble Space Telescope (HST). If launched, ATLAST would be a replacement and successor for the HST, with the ability to obtain spectroscopic and imaging observations of astronomical objects in the ultraviolet, optical, and infrared wavelengths, but with substantially better resolution than either HST or the planned James Webb Space Telescope (JWST). Like JWST, ATLAST will be launched to the Sun-Earth L2 Lagrange point.
ATLAST is envisioned as a flagship mission of the 2025–2035 period, designed to determine whether there is life elsewhere in the galaxy. It will attempt to accomplish this by searching for "biosignatures" (such as molecular oxygen, ozone, water, and methane) in the spectra of terrestrial exoplanets.
The backronym that the project currently uses, 'ATLAST', is in fact a pun. It refers to the time taken to decide on a true, visible-light, successor for the Hubble Space Telescope. However, it is expected as the project progresses, a new name will be chosen for the mission.
ATLAST will have a primary mirror diameter in the 8 m to 16.8 m range. Two different telescope architectures have been identified for ATLAST, but with similar optical designs, that span the range in technologies. The architectures are a telescope with a monolithic primary mirror and two variations of a telescope with a large segmented primary mirror. The concepts invoke heritage from the HST and JWST designs, but also take significant departures from these designs to minimize complexity, mass, or both. ATLAST will have an angular resolution that is 5–10 times better than JWST and a sensitivity limit that is up to 2,000 times better than HST.
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