After 35 years of perusing the universe, the Hubble Space Telescope remains a household name — the most well-recognised and scientifically productive telescope in history. Perched above Earth’s blurry atmosphere, Hubble’s crystal-clear views have been nothing less than transformative for the public’s perception of the cosmos. Through its evocative imagery, Hubble has made astronomy very relevant, engaging, and accessible for people of all ages. Hubble snapshots can portray the universe as awesome, mysterious, and beautiful — and at the same time chaotic, overwhelming, and foreboding.“Hubble opened a new window to the universe when it launched 35 years ago. Its stunning imagery inspired people across the globe, and the data behind those images revealed surprises about everything from early galaxies to planets in our own solar system,” said Shawn Domagal-Goldman, acting director of the Astrophysics Division at Nasa Headquarters in Washington. “The 10,800kg observatory was tucked away inside the space shuttle Discovery’s cargo bay and lofted into low Earth orbit on April 24, 1990. The telescope’s mission got off to a shaky start when an unexpected flaw was found in the observatory’s nearly 8ft diameter primary mirror. Astronauts came to the rescue on the first shuttle servicing mission in December 1993 to improve Hubble’s sharpness with corrective optics. Four more servicing missions followed (with the last one in 2009) when Hubble’s cameras, computers and other support systems were upgraded.More scientific papers than ever are based on Hubble data, thanks to the dedication, perseverance, and skills of engineers, scientists, and mission operators. To date, Hubble has made nearly 1.7mn observations, looking at approximately 55,000 astronomical targets. Hubble discoveries have resulted in over 22,000 papers and over 1.3mn citations as of February 2025. All the data collected by Hubble is archived and currently adds up to over 400 terabytes, representing the biggest dataset for a Nasa astrophysics mission besides the James Webb Space Telescope (JWST).Hubble’s long operational life has allowed astronomers to return to the same cosmic scenes multiple times to observe changes that happened during more than three decades: seasonal variability on the planets in our solar system, black hole jets travelling at nearly the speed of light, stellar convulsions, asteroid collisions, expanding supernova bubbles, and much more. Before 1990, powerful optical telescopes on Earth could see only halfway across the cosmos. Estimates for the age of the universe disagreed by a big margin. Supermassive black holes were only suspected to be the powerhouses behind a rare zoo of energetic phenomena. Not a single planet had been seen around another star.Among its long list of breakthroughs: Hubble’s deep field images unveiled myriad galaxies dating back to the early universe. The telescope also allowed scientists to precisely measure the universe’s expansion, find that supermassive black holes are common among galaxies, and make the first measurement of the atmospheres of exoplanets. Hubble also contributed to the discovery of dark energy, the mysterious phenomenon accelerating the expansion of universe, leading to the 2011 Nobel Prize in Physics.The relentless pace of Hubble’s trailblazing discoveries kick-started a new generation of space telescopes for the 21st century. Hubble provided the first observational evidence that there were myriad distant galaxies for Webb to pursue in infrared wavelengths that reach even farther beyond Hubble’s gaze. Now, Hubble and JWST are often being used in complement to study everything from exoplanets to galaxy evolution.Hubble is a project of international cooperation between Nasa and European Space Agency. Nasa’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for Nasa.