Deep Navy Space — 24 museum-grade prints in this palette. Compton GRO was the second of NASA's four Great Observatories — after Hubble and before Chandra, Spitzer, and the multi-wavelength program that transformed 1990s astrophysics. BATSE's burst catalog established that gamma-ray bursts were cosmological, not local solar-system phenomena, setting the stage for Swift and Fermi decades later. The Hubble Space Telescope deployed 25 April 1990 and initially returned blurred images due to a primary mirror polishing error discovered weeks after launch. Servicing Mission 1 in December 1993 installed corrective optics that unlocked the observatory's full potential, producing Deep Field images that revised estimates of galaxy counts and universe age. John Glenn became the first American to orbit Earth on Mercury-Atlas 6, completing three revolutions on 20 February 1962. The mission confirmed capsule attitude control, reentry procedures, and recovery operations for the Mercury program that bridged suborbital hops to Gemini rendezvous.