The Cosmological Advanced Survey Telescope for Optical and UV Research

In November 2006, more than a hundred astronomers from across Canada gathered at CSA headquarters in St. Hubert, QC, to participate in the Canadian Space Astronomy Workshop (CSAW). During the two-day workshop, astronomers were asked to identify opportunities and set priorities for space astronomy in Canada.

A top priority identified during the CSAW workshop was Canadian involvement in the design and development of a wide-field imaging space telescope. From 2007 to 2009, a number of Discipline Working Groups (DWGs) were established by CSA to further explore this, and other, options for space astronomy within Canada. A DWG (composed of about three dozens scientists from academia, industry and government) was formed to explore options in the field of wide-field imaging. The DWG concluded that

  1. “There is an overwhelming scientific need for a high-resolution, wide-field imaging  space telescope with an aperture of roughly ∼ 1m. Some of the key science drivers for such a facility include characterizing the nature of dark energy and measuring the equation of state of the universe; mapping the growth of dark matter structures as a function of cosmic time; observing directly the “gastrophysical” evolution of galaxies from “first light” to the present day; decoding the fossil record of the assembly of  baryons within merging dark matter halos in nearby galaxies; and characterizing the evolution  of star formation over cosmic time.”

and recommended that CSA explore the possibility of leading a smallSAT-sized mission dedicated to wide-field imaging at UV/optical wavelengths: i.e., “... a comprehensive feasibility study for a dedicated 1m-class facility, including a detailed cost and risk analysis, should be undertaken immediately.”

CSA sponsored a concept study for such a mission that was carried out between October 2011 and April 2012. This study led by COM DEV (Ottawa) and involving Magellan Aerospace, ABB Bomem, as well as about a dozen scientists from six Canadian universities and NRC/HIA — developed a concept for the CASTOR mission (The Cosmological Advanced Survey Telescope for Optical and UV Research). This proposed mission would make a unique, powerful, and lasting contribution to astrophysics by providing panoramic, high-resolution imaging in the UV/optical (0.15–0.55 μm) spectral region. A versatile ‘smallSAT’-class mission that would far surpass any ground-based optical telescope in terms of angular resolution, CASTOR would provide ultra-deep imaging in three broad filters to supplement longer-wavelength data from planned international dark energy missions (Euclid, WFIRST) as well as from the ground-based Large Synoptic Survey Telescope (LSST). Combining the largest focal plane ever flown in space, with an innovative optical design that delivers HST-quality images over a field two orders of magnitude larger than Hubble Space Telescope (HST), CASTOR would image about 1/8th of the sky to a (u-band) depth ~1 magnitude fainter than will be possible with LSST even after a decade of operations. No planned or proposed astronomical facility would exceed CASTOR in its potential for discovery at these wavelengths.

It is hoped that the CASTOR concept will proceed to a Phase A study in late 2012 or early 2013. For more information on the proposed mission, see the links below, or contact:

  1. Patrick Cote (NRC, Principal Investigator)

  2. Alan Scott (COM DEV, Project Manager)

  3. John Hutchings (NRC, Science team member)

Further Reading:

  1. Côté, P., et al. 2009, CSA Discipline Working Group Report on Wide-field UV/Optical/IR imaging from Space.

  2. Côté, P., et al. 2012, A Proposed, High-Resolution, Wide-Field Imaging Space Telescope: Summary of the CSA-Sponsored Canadian Space Telescope Mission Concept Study