Here we go! Gaia DR4 now has an official release date: 2 December 2026.

If you have been following the Gaia Mission closely, you will know that DR4 has had a sliding release date, from the end of 2025, to mid 2026 to "end of 2026". But now the date is locked.

https://www.cosmos.esa.int/web/gaia/data-release-4

Data Release 4 - Gaia - Cosmos

Gaia

DR4 is a big deal. The brighter stars will have half the parallax errors of DR3, astrometric parameters such as temperature, mass and radius, will be much improved, binary star data will be more reliable and for the first time ever, the release will include a catalog of Gaia-detected exoplanets.

Will Gaia DR4 distance and temperature estimates be reliable enough to detect spiral structure and provide the first detailed hints of what the Milky Way really looks like from the outside? MAYBE!