Dear Reader,
NASA launched the Nancy Grace Roman Space Telescope into space a couple weeks ago, aboard a SpaceX Heavy Falcon rocket. It will take about three months to reach its destination at the L2 Sun-Earth Lagrange Point. Its namesake is a NASA astronomer who is known as "The Mother of Hubble" for her key support in development of the Hubble Space Telescope.
This telescope has a MUCH bigger field of view (100X) than the Hubble or Webb telescopes, so it can perform large surveys much faster. It also has a MUCH better resolution than Hubble (but not Webb), and a clever method of blanking out a star's light so it can see exoplanets, which is one of the chief goals of this new device.
To get an idea of the improved field of view, the following image shows what the Roman Telescope will be able to see in one view, with the comparable view highlighted in the middle.
The plan is to use the new Roman Telescope to view a wide area, and when astronomers notice something interesting, they'll command the Webb Space Telescope to aim at that place, and get higher resolution images.
This video has an excellent summary of the new features of the Roman and how it will be used:
While we're on the topic of space telescopes, I've always been fascinated by the source of the failure in grinding the mirror for the original Hubble. I read about it long ago in IEEE Spectrum, but was unable to find a digital copy (they don't seem to put issues online before 2000). As I recall, the issue was that they had a rod of ultra-precise length and reflected laser light off a tiny spot on the end of the rod to guide their grinding. There was a black cap on the end of the rod with a hole in it so only that part of the reflective rod was visible to the laser. Unfortunately, the cap's paint chipped, leaving a portion of the cap reflective and throwing off the whole thing. A later test showed the spherical aberration, but they convinced themselves the test was wrong (it wasn't). Fortunately, because they knew precisely how far off the lens was made, they could make a corrective lens to compensate and install that in orbit, saving the much bigger cost of bringing it back to Earth to install a whole new mirror.
