An outstanding, multidisciplinary goal of modern science is the study of the diversity of potentially Earth-like planets and the search for life in them. This goal requires a bold new generation of space telescopes, but even the most ambitious designs yet can only hope to characterize several dozen potentially habitable planets. Such a sample may be too small to truly understand the complexity of exo-earths, which will likely need to be studied and interpreted as a network of coupled complex systems. We describe here a notional concept for a novel space observatory designed to characterize 1,000 transiting exo-earth candidates. The Nautilus Space Observatory concept is based on an array of identical spacecraft carrying very large diameter (8.5 m), very low weight, multi-order diffractive optical elements (MODE lenses) as light-collecting elements. The mirrors typical to current space telescopes are replaced by these MODE lenses, that have a 10 times lighter areal density and that are 100 times less sensitive to misalignments, enabling lightweight structures. MODE lenses can be cost-effectively replicated through molding. The Nautilus Space Observatory concept has a potential to greatly reduce fabrication and launch costs and mission risks compared to the current space telescope paradigm through replicated components and identical, lightweight unit telescopes. The Nautilus Space Observatory is designed to survey transiting exo-earths for biosignatures up to a distance of 300 pc, enabling a rigorous statistical exploration of the frequency and properties of life-bearing planets and the diversity of exo-earths. As the key step toward the full Nautilus Space Observatory, we also proposed the single-unit Nautilus Probe, a NASA Probe-class mission for exoplanet exploration, faint objects, and time-domain astrophysics. We present here an update on the Nautilus Space Observatory and Nautilus Probe concepts, as well as an update on the ongoing technology development work that advances the technology readiness level and the diameter of the ultralight MODE lenses, the key technolog that underpins these revolutionary space observatories.