A Window to the Stars: The Hubble Telescope
As November nights grow longer, we look skyward in the same spirit of wonder that once guided astronomer Edwin Hubble, born 136 years ago this week. His work revealed that our galaxy is but one of billions, forever expanding humanity’s sense of place in the cosmos. Nearly a century later, that same curiosity brought one of the greatest man-made feats to orbit: the Hubble Space Telescope. The National Archives holds records of the telescope's launch, various servicing missions, and the images themselves.
In the decades before Hubble, space imaging technology was limited by the distortions caused by Earth’s atmosphere, which blurred and obscured our views of the cosmos. Ground-based telescopes could only capture so much detail, leaving astronomers with incomplete or fuzzy images of distant stars and nebulae. At the time, the most advanced instrument was the Hale Telescope, completed in 1948 and located at the Palomar Observatory in California.
Then came the idea for a space-based telescope, championed by astronomers such as Lyman Spitzer, who envisioned an observatory free from the interference of Earth’s atmosphere. After years of study, design, and international collaboration, NASA and the European Space Agency partnered to make that vision a reality. Construction of the Hubble Space Telescope began in the 1970s, and after delays caused by technical and funding challenges, it was finally launched aboard the Space Shuttle Discovery on April 24, 1990.
Although Hubble’s early years were marked by challenges, including a flaw in its primary mirror that initially blurred its images, a series of repairs and upgrades soon transformed it into one of the most productive scientific instruments ever built. From its perch above Earth, the 43.5-foot-long telescope has captured more than 1.5 million observations, revealing galaxies billions of light-years away, tracing the birth and death of stars, and offering glimpses of planets beyond our solar system.
Images taken by Hubble, 1991
The space shuttle played a central role in Hubble’s success. Designed to carry large payloads into low Earth orbit and return them safely to Earth, the shuttle made it possible for astronauts to directly service and upgrade the telescope—something no previous spacecraft could do. Between 1993 and 2009, five shuttle crews conducted complex spacewalks, or extravehicular activities (EVAs), to replace instruments, repair components, and install advanced technology that extended Hubble’s lifespan and sharpened its vision. The shuttle’s Canadian-built robotic arm, the “Canadarm,” was essential to these missions, gently retrieving Hubble from orbit and holding it steady as astronauts worked in the vacuum of space.
Hubble’s mission has been as much about perseverance as discovery. From its early optical challenges to multiple astronaut-led servicing missions, the telescope’s story is about teamwork, innovation, and vision. Even after more than three decades in orbit, Hubble continues to deliver new science, revealing planets beyond our solar system and galaxies formed in the earliest epochs of the universe. You can continue to explore more out-of-this-world records from NASA in Record Group 255.
