The James Web telescope was supposed to launch in 2007 (and should be launching in November), and began development in 1996. Hubble was launch in 1990, and hav

The James Web telescope was supposed to launch in 2007 (and should be launching in November), and began development in 1996. Hubble was launch in 1990, and have 5 servicing missions for repairs and upgrades, with the last one being in 2009. An exact clone of Hubble is not nearly as useful as the first one, so it is reasonable to put your resources into a novel telescope. Unfourtuantly that telescope hit some scheduling challanges. Not to mention all the other space telescopes https://en.m.wikipedia.org/wiki/List_of_space_telescopes https://en.m.wikipedia.org/wiki/List_of_space_telescopes Which includes a gravitational telescope prototype.