Few telescopes can honestly say they've reinvented the concept, yet THE MOST certainly has. It works on a surprisingly old principle, by passing light through two prisms. As Isaac Newton demonstrated, this first splits light into its constituent components, then recombines it back again.

What's the point of that? You might well ask, and the answer is both intriguing and compelling: as the light emerges from the second prism, the focal distance can be controlled to a short distance from it.

With conventional mirror-based telescopes, the light is focussed some distance from the primary mirror, and that distance increases with the size of the mirror. Sending big things into space is both difficult and costly, and there is a reason why the Hubble Space Telescope is limited to the size it is. Additionally, sending a mirror into space is incredibly fraught with potential for disaster - a single crack or pit in the mirror and it can be ruined, and launching is a period filled with heavy vibration.

THE MOST (The High Étendue Multiple Object Spectrographic Telescope) resolves these issues. It uses a material that can be rolled up for launch and unrolled for deployment. It does not have to have the same tolerance for surface errors as a mirror, and is much lighter. Once in space, it is rigged to a framework printed on a 3D printer.

A small mirror catches the starlight as it emerges from the prism and directs it to the secondary prism. A small “grazing” angle allows this to occur very close to the primary prism surface. Further, the telescope can be much bigger and at significantly less cost than a conventional optical or radio telescope. Even better yet, it covers a vast area of the sky in detail without sacrificing angle as other telescope do when they 'zoom-in'.

https://www.nasa.gov/directorates/spacetech/niac/2019_Phase_I_Phase_II/The_Most/