¶The Nancy Grace Roman Space Telescope. Now that the JWST is deployed and could have a lifespan of 20 years 🎉 🥳, let’s talk about NASA’s next, next telescope. The wide-field infrared Nancy Grace Roman Space Telescope (née WFIRST) is scheduled to launch in 2025. Like JWST, it will also orbit at the Sun-Earth L2 point. The NGRST has two instruments: the Wide Field Instrument, a 300-megapixel camera with a Hubble-class 2.4 m aperture, but 100x the field of view, and the Coronagraph Instrument, for imaging and spectroscopy of nearby exoplanets. It is predicted to find 100,000 transiting exoplanets via both transit detection and microlensing. Microlensing occurs when, from our perspective, a star passes in front of a more distant star, and light from the further star is distorted by the gravity of the closer star and any exoplanets—the spatial and temporal difference in distortion due to the additional mass of one or more exoplanets is a telltale sign of their presence. Of the 4,884 exoplanets discovered so far, only 120 were found through microlensing. Through this technique, NGRST should be able to detect planets smaller than Earth—possibly approaching the size of moons like Ganymede—as well as stellar-mass black holes and rogue planets that are wandering the galaxy after having been ejected from their host stars. There is a proposal for a follow-on mission called the Starshade Rendezvous Probe (paper) which would add a 26 m starshade that would precisely position itself far in front of the telescope and allow direct imaging of nearby Earth-like exoplanets. The petal-shaped starshade would fly 20,000 to 40,000 km ahead of the telescope while maintaining a positional accuracy of only 1 meter, precisely blocking a star’s light but not the glow of its exoplanets. No big deal. This add-on mission would serve as a test ahead of even larger starshade companions to future observatories such as those called for by last year’s decadal survey. | 
