Tag Archives: HST

25 April 1990

Space Flight, , , , , , ,
Hubble Space Telescope after release from Discovery, STS-31, 25 April 1990. (NASA)
Hubble Space Telescope after release from Discovery, STS-31, 25 April 1990. (NASA)

25 April 1990: In orbit 380 miles (612 kilometers) above Earth, the crew of Discovery (STS-31) released the Hubble Space Telescope from the cargo bay.

This satellite was designed to study the universe in ultraviolet, visible and infrared light, with a clarity never before seen.

“The Mystic Mountain,” a dust cloud in the Carina Nebula, NGC 3372, approximately 7,500 light years from Earth. (NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)
A recent Hubble image of the Bubble Nebula, NGC 7635 (NASA)
A recent Hubble image of the Bubble Nebula, NGC 7635, an emission nebula at a distance of 11,000 light years. (NASA)
Dust shells illuminated by the star V838 Monocerotis, a red star approximately 20,000 light years away. (NASA, ESA and H.E. Bond (STScI)

© 2019 Bryan R. Swopes

24 April 1990, 12:33:51 UTC, T minus Zero

Space Flight, , , , , , , , , , , , , ,
Discovery (STS-31) lifts off Pad 39B with the Hubble Space Telescope. Sister ship Columbia waits on Pad 39A. (NASA)
Discovery (STS-31) lifts off Pad 39B with the Hubble Space Telescope. Sister ship Columbia waits on Pad 39A. (NASA)

24 April 1990, 12:33:51 UTC: Space Shuttle Discovery (STS-31) lifted off from Launch Complex 39B at the Kennedy Space Center, Cape Canaveral Florida, on a mission to place the Hubble Space Telescope in Earth Orbit.

The STS-31 flight crew were Loren J. Shriver, Commander; Charles F. Bolden, Jr., Pilot; Steven A. Hawley, Mission Specialist; Kathryn D. Sullivan, Mission Specialist; Bruce McCandless II, Mission Specialist.

Discovery (STS-31) flight crew: Seated, left to right: Colonel Charles F. Bolden, Jr., U.S. Marine Corps; Colonel Loren J. Shriver, U.S. Air Force; Lieutenant Commander Kathryn D. Sullivan, U.S. Navy. Standing, left to right: Captain Bruce McCandless II, U.S. Navy; Mr. Steven A. Hawley. (NASA)
Discovery (STS-31) flight crew: Seated, left to right: Colonel Charles F. Bolden, Jr., U.S. Marine Corps¹; Colonel Loren J. Shriver, U.S. Air Force; Lieutenant Commander Kathryn D. Sullivan, U.S. Navy.² Standing, left to right: Captain Bruce McCandless II, U.S. Navy; Mr. Steven A. Hawley. (NASA)

The Hubble Space Telescope is named after Edwin Hubble, an early 20th century astronomer who discovered galaxies beyond our own Milky Way galaxy. It is an optical Ritchey–Chrétien telescope (an improved Cassegrain reflector). Star light enters the telescope and is collected by a large 7 foot, 10.5 inch (2.400 meter) diameter hyperbolic mirror at the back end. The light is reflected forward to a smaller hyperbolic mirror, which focuses the light and projects it back through an opening in the main reflector. The light is then gathered by the electronic sensors of the space telescope. These mirrors are among the most precise objects ever made, having been polished to an accuracy of 10 nanometers.

The Hubble Space Telescope being deployed from Disovery's cargo bay. (NASA)
The Hubble Space Telescope being deployed from Discovery’s cargo bay, 25 April 1990. (NASA)

The Hubble Space Telescope is 43.5 feet (13.259 meters long. The light tube has a diameter of 10 feet (3.048 meters) and the aft equipment section is 14 feet (4.267 meters) in diameter. The spacecraft weighs 27,000 pounds (12,247 kilograms).

The HST orbits the Earth every 97 minutes at an altitude of 320 nautical miles (593 kilometers). The telescope was last serviced in 2009. Originally designed to operate for 15 years, the HST is now in its 26th.

The Hubble Space Telescope in Earth orbit. (NASA)
The Hubble Space Telescope in Earth orbit. (NASA)

¹ Colonel Bolden reached the rank of Major General, United States Marine Corps, before retiring in 2003. He was served as Administrator, National Aeronautics and Space Adminstration, 17 July 2009–20 January 2017.

² Lieutenant Commander Sullivan left NASA in 1993, and retired from the U.S. Navy with the rank of Captain, in 2006. She served as Under Secretary of Commerce for Oceans and Atmosphere/Administrator, National Oceanic and Atmospheric Administration (NOAA), 28 February 2013–20 January 2017.

© 2017,  Bryan R. Swopes