The James Webb Space Telescope, originally scheduled to be completed in 2007, now might be ready in 2020. If you still believe anything coming from Big Space. 

Meanwhile, Big Space claims it is under-funded. While it's true many worthy small experiments can't get the money they need, the reason is not due to the Bush, Obama or Trump administrations, it is because all three of them have watched JWST, the supposed successor to Hubble, bleed funding dry with its constant misses and overruns.

The appeal for science, though the public never had much enthusiasm, is that JWST will be able to see light from about 250-400 million years after the Big Bang whereas the Hubble Space Telescope sees back to only 800 million years. There is no question it is a fine scientific goal, but at the time it was approved there were concerns that the Clinton administration, which canceled the Superconducting Super Collider that had President Reagan's name attached, was creating its own "too big to fail" black hole for money. 

Originally it was going to take <$1 billion and 9 years to complete. In 2002 it got a new name (Webb), and was pushed back to 2010. It has only gotten worse from there. An outraged  Sen. Barbara Mikulski, D-Md., demanded an outside panel to look into cost controls after she learned the project managers had a 'joint confidence level' of only 50% of ever completing it. Basically, government was counting on the miracle of American free market technology to create a magical solution but then telling contractors who should be hired for jobs because it's a federal contract.

It was only supposed to last for 10 years, which means it is now so far behind schedule it would already need to be replaced. 

NASA has been forced to create an external Independent Review Board, whose findings will complement the Standing Review Board. It is hoped that an outside bolster confidence in NASA’s claims about when they will complete the final integration and test phase of the mission, the launch campaign, commissioning and the deployment sequence. If instead NASA successfully blames its contractors, we'll know they are determined to be a job works program and not get back to being an engineering body