MSE will use an 11.25 meter aperture telescope and dedicated multiobject fibre spectroscopy instrumentation to perform survey science observations, collecting spectra from more than 4,000 astronomical targets simultaneously.

[3] The project schedule anticipates receiving permission in 2021 to proceed to final design and construction phases, leading to a start of science commissioning in 2029.

[1] The MSE participants in 2018 consists of national-level or state-level organizations in Canada, France, Hawai‘i, Australia, China and India, with CFHT Corp as the executive agency for the project.

The General Lease confers upon UH the rights and obligations to operate in and to manage the Mauna Kea Science Reserve until 31 December 2033.

This will allow for highly complete statistical studies of the prevalence of stellar multiplicity into the regime of hot Jupiters for this and other samples, and also directly measure binary fractions away from the Solar Neighbourhood.

Chemistry has the potential to be used in addition to, or instead of, phase space to reveal the stellar associations that represent the remnants of the building blocks of the Galaxy.

MSE will provide a breakthrough in extragalactic astronomy by linking the formation and evolution of galaxies to the surrounding large-scale structure, across the full range of relevant spatial scales (from kiloparsecs to megaparsecs).

MSE will undertake an extragalactic time domain program to measure directly the accretion rates and masses of a large sample of supermassive black holes through reverberation mapping.

MSE will greatly extend the few 10s of relatively low-luminosity AGN that currently have measurements of their black hole masses based on this technique.

The mount concept is executed as a yoke-type structure and open space-frame telescope tube providing very good mechanical performance.

A calotte style enclosure[11] has been chosen as one that meets performance requirements, including good control of ventilation, while staying within the allowed mass and fiscal budgets.

Located in the outer chords between the hexagonal array of fibre positioners and the circular field of view are three imaging cameras used for telescope pointing acquisition, guidance, and focus measurement.

Software tools are being defined to automate steps in the operations sequence, going from survey definition to the delivery of science data.

MSE is designed to achieve its science objectives with the least impact possible on the Maunakea summit both during construction and when operating the resultant observatory.

The building internal structure will be improved to provide better performance during seismic events, and to accommodate the new enclosure and larger telescope.

Other changes involve relocating equipment and labs to better exhaust heat away from the observing environment, and providing space for segmented mirror routine cleaning and coating operations.