Physics does not exclude such an instrument. Budget does. Shipping complicated physical hardware to space requires that it absolutely must work on the first tr

Physics does not exclude such an instrument. Budget does. Shipping complicated physical hardware to space requires that it absolutely must work on the first try, and never require maintenance for the lifetime of the instrument. In contrast, the large earth-based telescopes can be regularly updated, maintained, and debugged. Access for such activities costs as much as a plane ticket to Chile, instead of a dedicated mission to space.