Final answer:
The Hubble Space Telescope and the Compton Gamma-Ray Observatory are both space-based telescopes launched in the early 1990s, focused on different parts of the electromagnetic spectrum but united by their contribution to NASA's great observatories program.
Step-by-step explanation:
The Hubble Space Telescope and the Compton Gamma-Ray Observatory are both space-based observatories launched by NASA in the early 1990s. The Hubble Space Telescope was launched in 1990 and is renowned for capturing images using ultraviolet radiation and visible light, providing a deep insight into the universe at these wavelengths. On the other hand, the Compton Gamma-Ray Observatory, launched in 1991, was dedicated to observing celestial events and objects in gamma rays. Both telescopes played a crucial role in exploring different spectra of the universe and expanded our understanding of cosmic phenomena through observations not possible from Earth. They share the similarity of being part of NASA's great observatories program, designed to cover a broad range of wavelengths: from gamma rays, through X-rays, to ultraviolet and visible light.