Space telescope to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all. Space observatories can generally be divided into two classes: missions which map the entire sky (surveys), and observatories which focus on selected astronomical objects or parts of the sky. Satellites have been launched and operated by NASA, ISRO, ESA, Japanese Space Agency and the Soviet space program later succeeded by Roskosmos of Russia. As of 2018, many space observatories have already completed their missions, while others continue operating on extended time. However, the availability of space telescopes and
Space Shuttle Pathfinder pan" to drop from a mounting bracket onto the external tank. The damaged area was part of the fiberglass and plywood added to the mockup before its exhibition in Japan. Space Shuttle Pathfinder The Space Shuttle Orbiter "Pathfinder" (unofficial Orbiter Vehicle Designation: OV-098) is a Space Shuttle test simulator made of steel and wood. Constructed by NASA in 1977 as an unnamed facilities test article, it was purchased in the early 1980s by the America-Japan Society, Inc. which had it refurbished, named it, and placed it on display in the Great Space Shuttle Exhibition in Tokyo. The mockup was later