Which one of NASA's "great observatories" was the first to be launched and is still gathering information on earth and its location in the galaxy

With the capabilities the Space Shuttle provides, scientist now have the means for deploying these observatories from the Shuttle's cargo bay directly into orbit. NASA's Hubble Space Telescope, the first of the great observatories, was deployed from the Space Shuttle Discovery into Earth orbit in April 1990.

the dark variety, as they are not visible on the dark tree barks

explanation: