When did Hubble start

space
"Hubble" space telescope turns 30

Black holes, distant galaxies, alien planets: the "Hubble" space telescope has turned our view of the cosmos inside out. With its often spectacularly colorful images, the flying observatory has not only provided groundbreaking scientific findings, but has also become part of popular culture. 30 years ago, on April 24, 1990, "Hubble" was lifted into space by the space shuttle "Discovery" of the US space agency NASA. A day later, the omnibus-sized observatory was placed in orbit at an altitude of 540 kilometers.

"Hubble" has made around 1.3 million observations since then, and more than 15,000 scientific publications have emerged from them. "Hubble has dramatically clarified our view of the universe," says Hubble veteran David Leckrone, who has served as the project's senior NASA scientist for many years. Above the earth's atmosphere, "Hubble" always has a clear view and the best observation conditions.

The space telescope can boast numerous successes in almost all fields of astronomy. Among other things, it has confirmed that gigantic black holes dwell in the centers of galaxies and that the cosmos is expanding ever faster. It determined this expansion speed with unmatched accuracy, discovered the so-called proto-planetary gas and dust disks from which new stars and planetary systems are formed, and looked back into early cosmic history, almost to the Big Bang.

Many of Hubble's fields of research were not even foreseeable when the space telescope was brought into orbit. In 1990, for example, no planets were known for other stars. In 2001 "Hubble" detected the first atmosphere of such an exoplanet and has since examined the atmospheres of distant planets around a hundred times. It was able to discover substances such as sodium, potassium and water vapor.

Telescope set new standards, not just in science

"'Hubble' was the first instrument that gave us this very, very unique insight," said exoplanet researcher Nikol Lewis from Cornell University in Ithaca, New York, recently at an anniversary seminar during the annual meeting of the American Astronomical Society AAS. The space telescope "heralded the era of comparative exoplanetology".

But the space telescope has not only impressed scientists. "'Hubble' brought the universe to people's homes," says project scientist Antonella Nota from the European space agency Esa. The Europeans have a 15 percent share in the space telescope. "It has made the beauty of the universe available to everyone around the world, not just as a privilege for a few professional astronomers."

The dazzling, beautiful images of the space telescope have long been found on mugs and bed linen, posters and advertising posters, in movies and even Bible calendars. The telescope itself has become synonymous with space exploration and has become a fixture in our everyday lives. "'Hubble' has been completely absorbed by pop culture," says Leckrone. "Many people living today were not even born when 'Hubble' was launched. They know of no world where 'Hubble' does not exist and does not reliably and regularly produce impressive scientific discoveries."

"We have flooded the world with breathtaking images." Ray Villard

The pictures have a large part in the popularity. "Before 'Hubble', the universe was a bit more boring," said Ray Villard, PR chief of the Space Telescope Science Institute (STScI) in Baltimore, at the AAS conference. "We have flooded the world with breathtaking images, month after month, year after year. The images appeal to the public on a visual and emotional level that goes far beyond understanding science."

All "Hubble" images are usually processed, if only because the space telescope can also receive ultraviolet and infrared light that is not visible to the human eye. So the colors in the pictures do not always correspond to the colors in nature. That is not the goal either, stressed Villard. Together with the scientists, the image experts attached great importance to making the essence of an astronomical object visible.

Success story with a bumpy start

But there's another reason the space telescope is so popular: "Drama," said Villard. "'Hubble's' story reads like a movie script. It has an arc of suspense." Before the start, there was a tense expectation of the unique telescope, which shortly afterwards gave way to disappointment and ridicule when it became apparent that the 2.4 meter main mirror was so defective that it did not provide a significantly better image quality than ground-based telescopes. "The mirror was manufactured very precisely - according to a wrong formula," said Leckrones successor Jennifer Wiseman at the AAS conference.

This was followed by an original and adventurous repair campaign in which NASA astronauts used corrective optics - "Hubble" got glasses and thus, after more than three years, his full eyesight. "The initial story of failure and recovery hit a nerve with the public like no other mission," says Esa researcher Nota. "It is a story of astonishing human ingenuity that has resulted in a collaboration across continents involving diverse groups of astronomers and engineers to find a solution that could restore the original capabilities."

The repair mission was not the only flight to "Hubble". Astronauts flew a total of five times to the 11-tonne observatory to bring it up to date with spectacular maneuvers, most recently in 2009. Since the NASA space shuttles were mothballed in 2011, "Hubble" has been left to its own devices. The flying observatory should meanwhile fall victim to the limited budget, but the mission was then extended - at the moment "open end".

Even if NASA wants to bring the next large observatory into space, the "James Webb Space Telescope" (JWST), "Hubble" should continue to work. The two telescopes complemented each other perfectly, emphasized Wiseman. "'Hubble' is fantastic in shape, technically and scientifically." The observatory is currently at the peak of its scientific output. "Hubble's" mission will be continued in the 2020s - "and if you are optimistic, maybe beyond".

dpa