It looks like the Space 220 Restaurant has changed how it operates its lounge. When the restaurant opened, the lounge was filled with walk-up first come, first served guests. The lounge was essentially an overflow option for guests who were looking for same-day availability.
Now, Disney is offering Space 220 Lounge advance dining reservations in addition to traditional restaurant reservations. You can book reservations via the My Disney Experience app or on the Walt Disney World website: https://disneyworld.disney.go.com/dining/epcot/space-220-lounge

The ability to make advance dining reservations for the lounge will likely cut down on walk-up, day-of availability as more guests become aware of the reservation system.
Note that the lounge menu is different than the regular restaurant menu, and you may not be able to order off of the prix-fixe menu at the lounge.
For our complete review of Space 220, including the lunge offerings, check our article below!

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I checked nearly everyday in December and no reservation times are available for lunch or dinner for three people. So yes, reservations may be live but nothing is available on the website.