Discover Space Telescopes

Overview of Space Telescopes

• Space telescopes are telescopes used to observe astronomical objects from outer space.
• The first operational space telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971.
• Space telescopes are divided into two types: satellites which map the entire sky (astronomical survey), and satellites which focus on selected astronomical objects or parts of the sky and beyond.
• They avoid the filtering and distortion (scintillation) of electromagnetic radiation which they observe, and avoid light pollution which ground-based observatories encounter.
• Space-based astronomy is more important for frequency ranges that are outside the optical window and the radio window, the only two wavelength ranges of the electromagnetic spectrum that are not severely attenuated by the atmosphere.
• X-ray astronomy is nearly impossible when done from Earth, and has reached its current importance in astronomy only due to orbiting X-ray telescopes such as the Chandra X-ray Observatory and the XMM-Newton observatory.
• Space telescopes are much more expensive to build than ground-based telescopes and are extremely difficult to maintain.
• The future availability of space telescopes and observatories depends on timely and sufficient funding.
• As of 2022, many space observatories have already completed their missions, while others continue operating on extended time.
• NASA, JAXA, and CNSA are planning future space observatories.
• On 16 January 2023, NASA announced preliminary considerations of several future space telescope programs, including the Great Observatory Technology Maturation Program (GOMAP), Habitable Worlds Observatory, and New Great Observatories.
• A list of space telescopes is available for reference.