By / par Patrick Côté (NRC Herzberg Astronomy & Astrophysics Research Centre)
(Cassiopeia – Summer / été 2018)
The Cosmological Advanced Survey Telescope for Optical and ultraviolet Research (CASTOR) is a proposed Canadian-led space telescope that has been in detailed study by the Canadian Space Agency (CSA) since 2011. The mission concept was developed in response to LRP2010, which identified Canada’s top priorities in space astronomy as “…significant involvement in the next generation of dark energy missions — ESA`s Euclid, or the NASA WFIRST mission, or a Canadian-led mission, the Canadian Space Telescope.” A detailed concept study for CASTOR was completed in 2012. Subsequent CSA-sponsored technical studies, undertaken between 2013 and 2017, further developed the mission concept by retiring sources of technical risk. In 2015, the mid-term review of LRP2010 recommended that the CSA immediately launch a Phase 0 study for CASTOR.
CASTOR is a 1-m telescope that uses a three-mirror-anastigmat design to deliver Hubble-like image quality (FWHM ~ 0.15”) over a wide field of view (0.5 deg x 0.5 deg) — nearly a hundred times larger than that of Hubble’s cameras. Complementing the Euclid and WFIRST missions, CASTOR would operate at UV/blue-optical wavelengths using dichroics to image simultaneously in three pass-bands that span the 0.15-0.55 micron region. CASTOR would also offer strong synergies with LSST by providing superior resolution and point-source sensitivity at blue-optical wavelengths, as well as direct access to the UV region. The latter will become a critical capability in the coming decade when HST will likely cease operations. In short, CASTOR would be a powerful vehicle for both surveys and Guest Observer programs, and would provide Canadian astronomers with a unique and strategic capability in the coming decade.
In the fall of 2017, CSA commissioned an extended Science Maturation Study (SMS) for the CASTOR mission that began in January 2018. The 14-month study, which will conclude in March 2019, will revise and update the CASTOR concept with an emphasis on the science case. Eight science working groups have been formed to explore scientific opportunities across a broad range of fields, from the cosmology to the solar system, with an eye towards updating the scientific requirements and optimizing the observing plan. Technical work is addressing all aspects of the mission design, including mission architecture, opto-mechanical design (including a possible spectrographic capability), satellite bus and launch options, ground segment requirements, and mission implementation plan.
The study — which will lead to an improved understanding of mission cost, schedule and risk, and involve an exploration of possible international partnerships and collaborations — is being led by Honeywell Aerospace (Ottawa), in collaboration with ABB Engineering (Quebec) and Magellan Aerospace (Winnipeg). The science team that consists of nearly 60 researchers at 17 Canadian universities and institutes. The study also involves major international partners — currently the Jet Propulsion Laboratory (JPL) and the Indian Institute of Astrophysics, who have been our partners in Astrosat, and are responding to an ISRO call for Astrosat2 proposals.
For more information on the CASTOR mission, see the project website.