With the Hubble Space Telescope aging and a newly revived Kepler Mission, many of the world's leading astronomers are championing the construction of The Advanced Technologies Large Aperture Space Telescope (ATLAST) is a concept for a space telescope with a mirror as large as 20 meters across — nearly ten times that of Hubble’s primary mirror — that NASA, the Space Telescope Science Institute and others have been developing for several years now. It's a telescope so huge that it may need to be constructed by astronauts in space rather than being launched aboard a single rocket.
The greatest leaps in our understanding of the universe typically follow the introduction of radically new observational capabilities that bring previously unobserved phenomena into view. Some, such as the unambiguous detection of life on an Earth-like planet orbiting another star, will be profound yet conceivable. Others are entirely beyond our imagination. All forever change our view of our place in the universe. ATLAST is envisioned as a flagship mission of the 2025 - 2035 period, designed to address one of the most compelling questions of our time. Is there life else where in our Galaxy? It will accomplish this by detecting"biosignatures" (such as molecular oxygen, ozone, water, and methane) in the spectra of terrestrial exoplanets.
ATLAST is a NASA strategic mission concept study for the next generation of UVOIR space observatory. ATLAST will have a primary mirror diameter in the 8m to 16m range that will allow us to perform some of the most challenging observations to answer some of our most compelling astrophysical questions. The pre;lininary team has identified two different telescope architectures, but with similar optical designs, that span the range in viable 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 HST and JWST design, 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 the James Webb Space Telescope (JWST) and a sensitivity limit that is up to 2000 times better than the Hubble Space Telescope (HST).
But ATLAST is more than just a "life-finder". ATLAST will have the performance required to reveal the underlying physics that drives star formation and to trace the complex interactions between dark matter, galaxies, and the intergalactic medium. Because of the large leap in observing capabilities that ATLAST will provide, we cannot fully anticipate the diversity or direction of the investigations that will dominate its use - just as the creators of HST did not foresee its pioneering roles in characterizing the atmospheres of Jupiter-mass exoplanets or measuring the acceleration of cosmic expansion using distant supernovae. ATLAST will have the versatility to far outlast the scientific vision of current-day astronomers.
The Daily Galaxy via http://www.stsci.edu/atlast and RAS