Hubble Space Telescope Hubble Observatory in Space This photograph of the Hubble Space Telescope was taken by the space shuttle Atlantis’ robotic arm during Servicing Mission 4. Credits: NASA Named in honor of the trailblazing astronomer Edwin Hubble, the Hubble Space Telescope is a large, space-based observatory, which has revolutionized astronomy since its launch and deployment by the space shuttle Discovery in 1990. Far above rain clouds, light pollution, and atmospheric distortions, Hubble has a crystal-clear view of the universe. Scientists have used Hubble to observe some of the most distant stars and galaxies yet seen, as well as the planets in our solar system. Edwin Hubble These images of the Eagle Nebula demonstrate Hubble’s ability to capture stunning images in both visible (left) and infrared (right) light. Credits: NASA Hubble’s capabilities have grown immensely in its over 30 years of operation. This is because new, cutting-edge scientific instruments have been added to the telescope over the course of five astronaut servicing missions. By replacing and upgrading aging parts, these servicing missions have greatly extended the telescope’s lifetime. Telescopes have a particular range of light that they can detect. Hubble’s domain extends from the ultraviolet through the visible (which our eyes see) and into the near-infrared. This range has allowed Hubble to deliver stunning images of stars, galaxies, and other astronomical objects that have inspired people around the world and changed our understanding of the universe. Hubble has made more than 1.5 million observations over the course of its lifetime. Over 19,000 peer-reviewed science papers have been published on its discoveries, and every current astronomy textbook includes contributions from the observatory. The telescope has tracked interstellar objects as they soared through our solar system, watched a comet collide with Jupiter, and discovered moons around Pluto. It has found dusty disks and stellar nurseries throughout the Milky Way that may one day become fully fledged planetary systems and studied the atmospheres of planets that orbit other stars. Hubble has peered back into our universe’s distant past, to locations more than 13.4 billion light-years from Earth, capturing galaxies merging, probing the supermassive black holes that lurk in their depths, and helping us better understand the history of the expanding universe. In its over 30 years of operation, Hubble has made observations that have captured humanity’s imaginations and deepened our knowledge of the cosmos. It will continue to do so for years to come. This documentary celebrates Hubble's scientific and technological achievements, as well as the human spirit that has kept it in orbit and operational for multiple decades. The Hubble Story In the Beginning Since the dawn of civilization, humans have been limited in their understanding of the universe by their vision and imagination. The telescope enhanced our vision and tempered our pride, as observations by Copernicus, Galileo and Kepler in the 16th and 17th centuries rebuffed the millennia-old conceit that Earth is the center of the universe, spearheading the Scientific Revolution. By the 18th century, the telescope had become the indispensable instrument for investigating the cosmos. Bigger and better telescopes were being built all over the world. Planets, stars and nebulas that could not be seen by the naked eye were being routinely noted and logged. Advances in photography, spectroscopy (splitting light into its component colors) and photometry (measuring the brightnesses of celestial objects) increased telescope versatility, sensitivity and discovery power. Enter Edwin Hubble By the turn of the 20th century, most astronomers believed that the observable universe consisted of one galaxy, our Milky Way, an oasis of stars, dust and gas in the vastness of space. However, in 1924, American astronomer Edwin Hubble used the 100-inch Hooker Telescope on Mount Wilson near Los Angeles, California, to study many other galaxies besides our own Milky Way, finding almost all of them moving away from each other. This suggested that the universe is expanding, unleashing a Pandora's box of seminal inquiries about the possible beginning and end of the universe — issues that are still being debated to this day. Photograph of NASA’s Hubble Space Telescope was taken on the fourth servicing mission to the observatory in 2009 Edwin Hubble stands by the 48-inch telescope at Palomar Observatory. Credits: Carnegie Institution of Washington Astronomers both before and after Edwin Hubble have toiled over long, frigid nights inside enormous dome-shaped observatories, pointing their telescopes skyward, yearning for the best possible glimpse of the heavens. However they faced a major obstacle that stood between them and a clear view of the universe: Earth's atmosphere. The atmosphere is a fluid, chaotic soup of gas and dust. It blurs visible light, causing stars to twinkle and making it difficult to see faint stars. It hinders or even totally absorbs other wavelengths of light, making observations of such wavelength ranges as infrared, ultraviolet, gamma rays and X-rays difficult or virtually impossible. (It is also these properties that protect us from the harmful effect of these rays.) Observatories with the largest of telescopes in various continents have been perched upon mountain tops and away from distracting city lights, with varying levels of success. Adaptive optics (using deformable mirrors to refocus blurred light from the cosmos) and other image-processing techniques have minimized — but not totally eliminated — the effects of the atmosphere. A Telescope in Space? A Telescope in Space This concept drawing from 1980 shows the original design features of Hubble and its Support Systems Module, which includes the communication equipment, pointing and control systems, and computer. Credits: NASA In 1923, German scientist Hermann Oberth, one of the three fathers of modern rocketry (along with Robert Goddard and Konstantin Tsiolkovsky), published "Die Rakete zu den Planetenraumen" ("The Rocket into Planetary Space"), which mentioned how a telescope could be propelled into Earth orbit by a rocket. In 1946, Princeton astrophysicist Lyman Spitzer wrote about the scientific benefits of a telescope in space, above Earth's turbulent atmosphere. Following the launch of the Soviet satellite Sputnik in 1957, the fledgling National Aeronautics and Space Administration (NASA) successfully launched two Orbital Astronomical Observatories (OAOs) into orbit. They made a number of ultraviolet observations and provided learning experiences for the manufacture and launch of future space observatories. The Large Space Telescope Hubble Scientific Instruments Hubble’s scientific instruments analyze different types of light ranging from ultraviolet (UV) to infrared (IR). This graphic shows which wavelengths each instrument studies. Credits: NASA Meanwhile, scientific, governmental and industrial groups planned the next step beyond the OAO program. Spitzer gathered the support of other astronomers for a "large orbital telescope" and addressed the concerns of its critics. In 1969, the National Academy of Sciences gave its approval for the Large Space Telescope (LST) project, and the hearings and feasibility studies continued. After Armstrong's "giant leap for mankind" on the Moon in 1969, funding for NASA space programs began to dwindle, putting the LST program in jeopardy. LST planners had to design the telescope under budget constraints. A number of downsizing measures were considered, such as decreasing the size of the primary mirror, the number of scientific instruments, or the number of spare parts created and tests performed. Ultimately, the size of the main mirror was reduced from 120 inches to 94. In 1974, the LST Science Working Group recommended the space telescope carry a large complement of interchangeable instruments. The requirements for these instruments were to resolve at least one-tenth of an arcsecond (or 1/36,000 of a degree of arc across the sky), and have a wavelength range from ultraviolet through visible to infrared light. The Space Shuttle diagram of space shuttle This drawing shows an overview of the Space Shuttle. Credits: NASA NASA and its industrial partners — called contractors — brought up the option of developing a vehicle that could achieve orbit, return to Earth intact and be reused repeatedly; the concept of the space shuttle was born. The space shuttle could deploy the LST into space and reel it back for return to Earth. In turn, the telescope’s designers created the telescope to fit snugly inside the shuttle’s cargo bay. NASA suggested that the lifetime of the space telescope be 15 years, which implied that the instruments needed to be replaced periodically on the ground or even serviced in orbit — an ability not afforded to any satellite before or since. Scientists also had to balance the size and quantity of scientific instruments versus their cost. Too many instruments meant financial support was less likely; conversely, instruments of minimal capability would result in the loss of scientific support for the telescope. The European Space Agency (ESA) joined the project in 1975 and provided fifteen percent of the funding of the LST via contribution of the Faint Object Camera (FOC) and the solar arrays. In return, NASA guaranteed at least fifteen percent of telescope time — the amount of time astronomers use the telescope for space observations — to European astronomers. In 1977, Congress approved funding to build one of the most sophisticated satellites ever constructed. Who Does What? NASA chose Marshall Space Flight Center in Huntsville, Alabama, as the lead NASA field center for the design, development and construction of the space telescope. Marshall delegated Perkin-Elmer Corporation (now Hughes Danbury Optical Systems) the task of developing the Optical Telescope Assembly and the Fine Guidance Sensors. Lockheed Missiles and Space Company (now Lockheed Martin) was selected by Marshall to build the spacecraft’s outer structure and the Support Systems Module (the internal support systems, which include the computer, power, communications, pointing and control systems) and then assemble the telescope together. NASA chose Goddard Space Flight Center in Greenbelt, Maryland, to be the lead in scientific instrument design and ground control for the space observatory. Scientists were organized into "Instrument Definition Teams," which would translate scientific aims into scientific devices and incorporate them into the space telescope housing. After an announcement was made to the astronomy community, proposals were received and judged, and five devices were selected as the initial instruments that would be aboard the space telescope: the Faint Object Camera, the Wide Field/Planetary Camera, the Faint Object Spectrograph, the High Resolution Spectrograph and the High Speed Photometer. The Johnson Space Center in Houston, Texas, and the Kennedy Space Center in Florida supplied space shuttle support. In all, dozens of contractors, a handful of universities and several NASA centers, spanning 21 states and 12 other countries worldwide, made the dream of a telescope above the clouds and in space a reality. In 1983, the Space Telescope Science Institute (STScI) was established at The Johns Hopkins University in Baltimore, Maryland. The staff of STScI would evaluate proposals for telescope time and manage the resulting telescope observations. A number of delays stemming from underestimating the costs and engineering requirements of the state-of-the-art telescope caused the launch date to be moved from December 1983 to the second half of 1986. NASA re-examined interfaces, instruments and assemblies. The building of the Optical Telescope Assembly encountered engineering challenges. Scientific instruments, such as the Wide Field/Planetary Camera (WF/PC), underwent redesign, removing weight and redundancy. Image of Hubble over Earth Astronauts Steven L. Smith and John M. Grunsfeld replace gyroscopes during Servicing Mission 3A in December 1999. Credits: NASA Hubble Is Born To maintain and upgrade the space telescope, plans were made to conduct servicing missions in orbit versus returning the telescope to Earth and refurbishing it on the ground. It was an innovative concept that would be even easier on a budget. In the midst of this spirit of renovation, the space telescope was renamed the Hubble Space Telescope (HST). By 1985, the telescope was assembled and ready for launch. However, in 1986 disaster struck. The Challenger accident forced NASA to ground the space shuttle fleet for two years. The HST Project used that time to perform further work on the telescope. Solar panels were improved with new solar cell technology. The aft shroud (the end of the telescope that houses the science instruments) was modified to make instrument replacement during servicing easier. Computers and communication systems were upgraded. The space telescope was subjected to further stress tests to prepare for the harsh conditions of liftoff and space. Finally, on April 24, 1990, the space shuttle Discovery lifted off from Earth with the Hubble Space Telescope nestled securely in its bay. The following day, Hubble was released into orbit, ready to peer into the vast unknown of space, offering a glimpse at distant, exotic cosmic shores yet to be described. Hubble’s Mirror Flaw Hubble Mirror Flaw Prior to installation, technicians inspect the primary mirror of the Hubble Space Telescope (HST). Credits: NASA When Hubble began returning science data to Earth, astronomers did not see crisp, point-like images of stars. Instead, they saw stars surrounded by large, fuzzy halos of light. They soon realized that this issue was created because the edges of the telescope’s primary mirror were ground too flat by just a fraction of the width of a human hair. Although perfectly smooth, the mirror could not focus light to a single point. It had been ground to the wrong shape because of a flaw introduced into the test equipment used to evaluate the mirror’s curvature prior to launch. Although engineers designed Hubble with many replaceable components, the primary mirror was not one of them. However, the ability for astronauts to upgrade the observatory in orbit ultimately led to a solution for this seemingly unconquerable problem. Before NASA even launched Hubble, engineers were hard at work building an improved, second-generation camera for the space telescope. This instrument, called the Wide Field and Planetary Camera 2 (WFPC2), was meant for installation by astronauts at a future date. Optics experts realized they could build corrective optics into this camera to counteract the flaw in the primary mirror. Meanwhile, Hubble scientists and engineers devised a set of nickel- and quarter-sized mirrors to remedy the effects of the primary mirror on Hubble’s other instruments. Labeled the Corrective Optics Space Telescope Axial Replacement (COSTAR), this refrigerator-sized device could deploy the corrective mirrors into the light paths of the telescope’s other science instruments to focus their images properly. > Learn more about Hubble’s mirror flaw. Servicing Missions Hubble was designed to be serviced periodically by astronauts in space, and was therefore built with modular components that are astronaut-friendly to handle and replace. This allowed the telescope to be equipped with new, state-of-the-art science instruments and other equipment during five servicing missions from 1993 to 2009. In December 1993 the first servicing mission (SM1) launched. New instruments were installed such as the WFPC2 and COSTAR, which countered the effects of the primary mirror’s flawed shape. Hubble Servicing Missions Astronaut Kathryn Thornton works on Hubble during Servicing Mission 1. Credits: NASA In February 1997 the second servicing mission (SM2) took place, resulting in the replacement of degrading spacecraft components, and the installation of new instruments such as the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). STIS separated the light the telescope took in, and “dissected” it so that the composition, temperature, motion and other properties could be analyzed. With NICMOS astronomers could see the first clear views of the universe at near-infrared wavelengths. On November 13, 1999, the fourth of six gyroscopes (gyros) failed on Hubble, and the telescope temporarily closed its eyes on the universe. Gyros measure the spacecraft’s rate of motion and help point Hubble toward its observation target. Unable to conduct science without three working gyros, Hubble entered a state of dormancy called safe mode. Essentially, Hubble “went to sleep” while it waited for help. Hubble’s third servicing mission was originally conceived as one of maintenance, but when the fourth gyro failed NASA split the mission into two parts: Servicing Mission 3A (SM3A) flew in December 1999 and Servicing Mission 3B (SM3B) in March 2002. SM3A astronauts replaced all six gyroscopes with new ones, and installed a faster, more powerful main computer, a next-generation solid-state data recorder, a new transmitter, new insulation and other equipment. During SM3B, astronauts installed a new science instrument called the Advanced Camera for Surveys (ACS). ACS sees in wavelengths ranging from visible to far-ultraviolet, and can produce 10 times the science results in the same amount of time than the camera it replaced, the Faint Object Camera (FOC). Servicing Mission 4 (SM4), the fifth visit to Hubble, occurred in May 2009. Astronauts installed two new scientific instruments: the Cosmic Origins Spectrograph (COS) and Wide Field Camera 3 (WFC3). Two failed instruments, the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS), were brought back to life by the first-ever on-orbit instrument repairs. In order to prolong Hubble’s life, other components were replaced including new batteries, new gyroscopes and a new science computer. In addition, a device was attached to the base of the telescope to facilitate de-orbiting when the telescope is eventually decommissioned. Each of the servicing missions has been crucial to Hubble’s success and longevity. The servicing missions have enhanced the telescope’s science capabilities, leading to fascinating new discoveries about the universe. > Learn more about Hubble’s servicing missions. Hubble Today Hubble’s mission was to spend at least 15 years probing the farthest and faintest reaches of the cosmos. Hubble has far exceeded this goal, operating and observing the universe for over 30 years. During its time in orbit, the telescope has taken more than 1.5 million observations, and astronomers have used that data to publish more than 19,000 peer-reviewed scientific publications on a broad range of topics. With any piece of machinery that’s 30 years old comes some aging parts. No more servicing missions are scheduled to repair or replace equipment on Hubble. However, a dedicated team of engineers and scientists are continuously working to keep Hubble operating for as long as possible. For example, Hubble’s engineers have figured out a way the telescope could continue observing the universe on only one gyro, using other types of sensors on the spacecraft to make up for gyros that have failed. This and other innovations designed to extend the lifetime of Hubble’s equipment will keep the telescope exploring for years to come. While nearly impossible to provide a comprehensive list of all the scientific contributions Hubble has made so far during its career, the telescope’s observations have contributed to the understanding of the development and growth of galaxies, the presence of black holes in most galaxies, the birth of stars, and the atmospheric composition of planets outside our solar system. Hubble’s explorations have fundamentally changed our perception of the universe and will continue to reveal new insights for many more years. > Learn more about some of Hubble’s scientific discoveries. Hubble Facts The Hubble Space Telescope is an optical telescope that orbits Earth. This vantage point allows it to obtain a view of cosmic objects unobstructed by Earth's atmosphere, which can distort light and block certain wavelengths. NASA named Hubble after American astronomer Edwin P. Hubble (1889–1953). Hubble confirmed an "expanding" universe, which provided the foundation for the Big Bang theory. Mission Launch: April 24, 1990, from space shuttle Discovery (STS-31) Deployment: April 25, 1990 First Image: May 20, 1990: Star cluster NGC 3532 Servicing Mission 1 (STS-61): December 1993 Servicing Mission 2 (STS-82): February 1997 Servicing Mission 3A (STS-103): December 1999 Servicing Mission 3B (STS-109): February 2002 Servicing Mission 4 (STS-125): May 2009 Size Length: 43.5 feet (13.2 m) Weight: At Launch: about 24,000 pounds (10,886 kg) Post SM4: about 27,000 pounds (12,247 kg) Maximum Diameter: 14 feet (4.2 m) Spaceflight Statistics ​Low Earth Orbit: Altitude of 340 miles (295 nautical miles, or 547 km), inclined 28.5 degrees to the equator Time to Complete One Orbit: about 95 minutes Speed: about 17,000 mph (27,300 kph) Optical Capabilities Sensitivity to Light: Ultraviolet through Infrared (115–2500 nanometers) Hubble's Mirrors Primary Mirror Diameter: 94.5 inches (2.4 m) Primary Mirror Weight: 1,825 pounds (828 kg) Secondary Mirror Diameter: 12 inches (0.3 m) Secondary Mirror Weight: 27.4 pounds (12.3 kg) Pointing Accuracy In order to take images of distant, faint objects, Hubble must be extremely steady and accurate. The telescope is able to lock onto a target without deviating more than 7/1000th of an arcsecond, or about the width of a human hair seen at a distance of one mile. Data Statistics Hubble transmits about 150 gigabits of raw science data every week. Power Needs Energy Source: The Sun Mechanism: Two 25-foot solar panels Power Generation (in sunlight): about 5,500 watts Power Storage Batteries: 6 nickel-hydrogen (NiH) Storage Capacity: Equal to about 22 average car batteries Did you know? Hubble has made more than 1.5 million observations since its mission began in 1990. Astronomers using Hubble data have published more than 19,000 scientific papers, making it one of the most productive scientific instruments ever built. Those papers have been cited in other papers over 900,000 times. Hubble does not travel to stars, planets, or galaxies. It takes pictures of them as it whirls around Earth at about 17,000 mph (27,000 kph). Hubble has circled Earth and gone more than 4 billion miles (6 billion km) along a circular Earth orbit currently about 340 miles (547 km) in altitude. Hubble has no thrusters. To change angles, it uses Newton’s third law by spinning its wheels in the opposite direction. It turns at about the speed of a minute hand on a clock, taking 15 minutes to turn 90 degrees. Hubble has the pointing accuracy of 0.007 arcsecond, which is like being able to shine a laser beam on President Roosevelt’s head on a dime about 200 miles (320 km) away. Outside the haze of our atmosphere, it can see astronomical objects with an angular size of 0.05 arcsecond, which is like seeing a pair of fireflies in Tokyo that are less than 10 feet (3 m) apart from Washington, D.C. Due to the combination of optics and sensitive detectors and with no atmosphere to interfere with the light reaching it, Hubble can spot a night light on the surface of the Moon from Earth. Hubble has peered back into the very distant past, to locations more than 13.4 billion light-years from Earth. Hubble generates about 10 terabytes of new data per year. The total archive is currently over 150 TB in size. Hubble weighed about 24,000 pounds (10,800 kg) at launch but if returned to Earth today would weigh about 27,000 pounds (12,200 kg) — on the order of two full-grown African elephants. Hubble's mirror is about 7.9 feet (2.4 m) across. It was so finely polished that if you scaled it to be the diameter of the Earth, you would not find a bump more than 6 inches (15 cm) tall. Hubble is 43.5 feet (13.2 m) long — the length of a large school bus.