Presentation #151.03 in the session “Space-based Instrumentation”.
Hybrid instruments combining ground and space assets can open at least three new doors in space and Earth science. Orbiting guide stars can enable high-performance visible-band adaptive optics for the largest ground-based telescopes, with almost the sensitivity and angular resolution that they would have in space. Beginning with one and building to a fleet of orbiting beacons would bring this revolution to all large telescopes. Orbiting calibrators can connect both astrophysical observations and Earth science to NIST-traceable standards, with benefits to fundamental physics, measurements of the dark energy, and long-term trends in Earth climate. The coming Extremely Large Telescopes (GMT, TMT, and TMT) can observe reflected light images and spectra of oxygen and water from exo-Earths around Sun-like stars, if an orbiting starshade 100 m across in the right orbit can match the observatory velocity.