The European Space Agency says it will delay the launch of a galaxy-mapping spacecraft due to a technical issue with some on-board components.

The launch of the Gaia mission -- intended to survey billions of stars to create a precise 3-D map of our Milky Way galaxy -- was postponed Tuesday after a technical issue was identified in another satellite already in orbit that shares some components with the Gaia spacecraft.

To avoid potential problems, the components on Gaia -- two transponders generating timing signals for down-linking the science telemetry -- will be replaced, the ESA's Paris headquarters announced Wednesday.

The transponders will be removed from Gaia, currently at the ESA Kourou spaceport in French Guiana, and returned to Europe where the potentially faulty components will be replaced and verified, the agency said.

The change means it will not be possible to meet the previously targeted launch date of Nov. 20, ESA scientists said; the next available launch window is Dec. 17 to Jan. 20, 2014.