The James Webb Space Telescope (JWST) comes up a lot when we talk about the very boundaries of our understanding of the cosmos. For more than a quarter century, the Hubble Space Telescope has been our best window to the wider universe, but it can only do so much. The JWST is the next step, and NASA has announced that is has completed construction of the telescope and it’s on track to launch in just under two years.
The journey to this point was almost derailed a few times. The JWST was an expensive project at its inception, with an estimated budget of $5 billion. A series of delays and technical issues nearly resulted in the cancellation of the JWST in the 2012 US federal budget. Luckily, the project survived and is now back on track. However, the cost did end up ballooning to about $8.5 billion. By comparison, Hubble cost $2.5 billion.
This new telescope was designed the far surpass Hubble’s capabilities. If you’ve seen even a few of the stunning images from Hubble or seen how often its data is cited in scientific studies, that should excite you. For starters, the JWST has much larger reflecting mirrors — a total area of 270 square feet composed of 18 hexagonal beryllium coated mirrors. Hubble’s mirror has an area of just 48 square feet. This means the Webb Telescope will be able to see much fainter objects than Hubble.