James Webb Space Telescope
The successor to Hubble, the James Webb will feature a 6.4 meter mirror, dwarfing the 2 meter mirror on Hubble. It will focus on the infrared spectrum and will see further into the past than ever before. It’s currently scheduled to launch in 2021, but has been delayed multiple times.

WFIRST
The Wide Field Infra Red Survey Telescope will have the same resolution as Hubble, but will be able to image 100x more of the sky at once. The plan was to use it in conjunction with the James Webb to find interesting targets. It is in danger of being cancelled later this year.

LUVOIR
The Large UV/Optical/Infrared Telescope would have a mirror between 8 and 16 meters wide and will collect light in all wavelengths. This is a massive space telescope that is too big for any current rockets, though could be carried up on the SLS, New Glenn, or SpaceX Starship.

Thirty Meter Telescope
This massive ground-based telescope has faced numerous delays due to native Hawaiians protesting it being built on Mauna Kea, which they consider sacred land. This telescope would have 20x the power of Hubble.

Extremely Large Telescope
Currently being built in the Atacama desert of Chile, this 39-meter wide mirror will focus on the infrared spectrum and should answer some of the biggest questions about universal expansion.

Large Magellan Telescope
Constructed out of 7 8-meter wide mirrors – the largest in the entire world – this telescope is the simplest of the telescopes, which should allow for optimal optics.

FAST
This Chinese radio telescope took the prize from Arecibo in Puerto Rico as the largest telescope in the world, and even though they’re still calibrating it, it has already discovered dozens of pulsars.

Large Synoptic Survey Telescope
While not impressively huge, the LSST is exciting because of how it will be used – to scan the entire sky every 3 days. Over 10 years, the amount of data this telescope will produce will equal 50 petabytes and could help find new planetary objects in our own solar system.