Friday, April 24, 2015

Hubble Space Telescope Turns 25

Hubble Space Telescope orbiting Earth. Credit: NASA/ESA

On 24 April 1990 the NASA/ESA Hubble Space Telescope was sent into orbit aboard the space shuttle Discovery as the first space telescope of its kind. It offered a new view of the Universe and has, for 25 years, reached and surpassed all expectations, beaming back data and images that have changed scientists’ understanding of the Universe and the public’s perception of it. "Even the most optimistic person to whom you could have spoken back in 1990 couldn’t have predicted the degree to which Hubble would re-write our astrophysics and planetary science textbooks," said Charlie Bolden, NASA administrator and pilot of the mission that brought Hubble into orbit. "A quarter century later, Hubble has fundamentally changed human understanding of the universe and our place in it."

Shortly after Hubble was deployed in 1990, the observatory's primary mirror was discovered to have a flaw that affected the clarity of the telescope's early images. Astronauts repaired Hubble in December 1993. Including that trip, there have been five astronaut servicing missions to Hubble. The first servicing mission occurred Dec. 2-13, 1993. Subsequent servicing missions occurred on Feb. 11-21, 1997; Dec.19-27, 1999; March 1-12, 2002; and May 11-24, 2009.

In this April 25, 1990, photograph taken by the crew of the STS-31 space shuttle mission, the Hubble Space Telescope is suspended above shuttle Discovery's cargo bay some 332 nautical miles above Earth. The Canadian-built Remote Manipulator System (RMS) arm, controlled from in-cabin by the astronaut crew members, held the huge telescope in this position during pre-deployment procedures, which included extension of solar array panels and antennae. Credit: NASA
In this April 25, 1990, photograph taken by the crew of the STS-31 space shuttle mission, the Hubble Space Telescope is suspended above shuttle Discovery's cargo bay some 332 nautical miles above Earth. The Canadian-built Remote Manipulator System (RMS) arm, controlled from in-cabin by the astronaut crew members, held the huge telescope in this position during pre-deployment procedures, which included extension of solar array panels and antennae. Credit: NASA

Hubble’s scientific payoff has been immeasurable; it has shown us the universe as we never imagined.

“Hubble has changed the course of science with its discoveries and shown us the depth and beauty of the universe,” said John Grunsfeld, Hubble astronaut and associate administrator of NASA’s Science Mission Directorate at NASA Headquarters, Washington. “With both new observations and treasures hidden in the existing archive of data Hubble will continue to unravel the mysteries of the cosmos in the years ahead.”

Above the hazy blur of Earth’s atmosphere, Hubble provides a larger-than-life, “super-rainbow” view of the universe: from ultraviolet, visible, and into near-infrared wavelengths of light. Hubble’s fantastic images unveil both beauty and cataclysmic disturbances across an unimaginably deep cosmic tapestry. Combined with the powers of NASA’s Great Observatories, Chandra, Spitzer, and the deorbited Compton Gamma Ray Observatory, Hubble painted a picture of the solar system and beyond that has changed astronomy forever.

Initially tasked to measure the expansion rate of the universe, find very distant galaxies, and investigate black holes, Hubble’s research has now covered nearly every frontier in deep-space astronomy: the expansion and acceleration rate of the universe, the apparent link between galaxy mass and central black hole mass; early galaxy formation shortly after the Big Bang; strange transient events in space; and the chemistry and potential habitability of planets orbiting other stars.

From its vantage point roughly 350 miles above Earth, Hubble has become "the most fertile scientific instrument there ever was," said astrophysicist Neil deGrasse Tyson, director of New York's Hayden Planetarium. "Hubble turned the galaxy into our backyard."

From planets to planetary nebula, and from star formation to supernova explosions, the NASA/ESA Hubble Space Telescope has captured a wealth of astronomical objects in its 25-year career. This montage presents 25 images that sample the space telescope’s rich contribution to our understanding of the Universe around us. Credit: ESA
From planets to planetary nebula, and from star formation to supernova explosions, the NASA/ESA Hubble Space Telescope has captured a wealth of astronomical objects in its 25-year career. This montage presents 25 images that sample the space telescope’s rich contribution to our understanding of the Universe around us. Credit: ESA

Hubble’s long exposures of the far universe have unveiled an “undiscovered country” of discordant objects, violent explosions, and tumultuous galaxy collisions. They tell the story of the dynamic evolution of the universe from the Big Bang.

Hubble has also provided a fascinating view of our own dynamic solar system, revealing colliding asteroids, changing aurorae and weather on planets and moons, and even enabling the detection of previously unknown moons.

More than being just a tool for astronomers, Hubble is the people’s telescope. It is one of the most influential scientific instruments ever built, reinvigorating and reshaping what the world perceives as outer space. Its images and discoveries have captured the imagination of people around the world, touching everything from pop culture to science fiction, from academia to art. Hubble has also substantially improved science, technology, engineering and mathematics (STEM) education nationwide. Its education materials are used by half a million teachers and six million students annually in all 50 states.

Thanks to five space shuttle servicing missions, totaling 32 astronaut space walks, and the multitude of scientists, engineers, and staff that worked on Hubble, the observatory has long out-lasted its planned end-of-mission in 2005. The observatory’s science capabilities are more powerful than at its launch, with upgraded instruments, computers, and control systems operating at top performance until at least the end of the decade.

NASA's Jet Propulsion Laboratory in Pasadena, California, is also celebrating its role in the historic mission this week. JPL designed and built the camera that saved Hubble after a flaw in the telescope's primary mirror was discovered shortly after its launch in 1990. The Wide Field and Planetary Camera 2, or WFPC2, was carefully designed to be out of focus to the same degree as Hubble's primary mirror, only in the opposite direction. In 1993, astronauts aboard the space shuttle Endeavour installed the camera, restoring the mission's ability to take sharp images.

Another instrument was also installed during this servicing mission, called the Corrective Optics Space Telescope Axial Replacement (COSTAR), which acted like a prescription lens to fix the remaining instruments on Hubble.

Former University of Colorado Boulder Senior Research Associate Jack Brandt, now retired, led the science team for the Goddard High Resolution Spectrograph, one of eight instruments aboard Hubble when it launched April 24, 1990. In 2009, during the final Hubble servicing mission, astronauts installed the $70 million Cosmic Origins Spectrograph (COS), designed by a team led by Professor James Green of CU-Boulder’s Center for Astrophysics and Space Astronomy and which included 14 CU-Boulder astronomers.

“It’s hard to believe it’s been 25 years,” said CU-Boulder Professor Michael Shull, a co-investigator on COS and faculty member at CASA. “CU-Boulder not only had a huge role in building Hubble, but also in using it.” The COS science team received 552 orbits of observing time with the observatory, which included use by both graduate and undergraduate students.

With support from ESA (European Space Agency), Hubble has served as a trailblazer for planning humanity's next big step into the cosmos. The James Webb Space Telescope (JWST), a partnership with ESA and the Canadian Space Agency, is scheduled for launch in 2018 and will see farther back in time than Hubble with its extended infrared capabilities. JWST will reveal fledgling galaxies from the first 200 million years after the Big Bang. It will also peer deeply into the dusty planet-forming disks around young stars that Hubble often sees in silhouette, and push the boundaries of learning about planets orbiting other stars.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

Edwin Hubble (1889 - 1953) discovered the expanding nature of the universe. He also was the first to comprehend the nature of how fast galaxies move and his work became a major basis for the big-bang theory of how the universe began. Hubble’s discoveries fundamentally changed the scientific view of the universe. Among his most significant came in 1929 when he determined that the farther a galaxy is from Earth, the faster it appears to move away. This notion of an “expanding” universe formed the basis of the big-bang theory, which states that the universe began with an intense burst of energy at a single moment and has been expanding since

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