Key Take-aways on the Hubble Space Telescope:
The Hubble Space Telescope launched on April 24, 1990 and is celebrating its 35th anniversary in 2025.
The telescope has a 2.4-meter mirror, main types of science instruments, including a suite of spectrographs and cameras that have been upgraded through five astronaut-serviced missions.
From mapping dark matter to refining the Hubble Constant, the rate at which the universe expands, the Hubble Space Telescope has been central to some of the most transformative discoveries of the past half-century.
On April 24, 1990, Space Shuttle Discovery launched from Kennedy Space Center carrying one of the most ambitious science instruments ever built: the Hubble Space Telescope. Suspended in low-Earth orbit at an altitude of some 320 miles, far above the atmospheric distortions that blur ground-based views, Hubble promised to revolutionize astronomy. And though it had a bit of a bumpy start, over the past 35 years, it has done just that.
From capturing the earliest glimpses of galaxy formation to measuring the expansion rate of the universe, Hubble has been at the heart of modern astronomy for decades. Its images are now iconic: pillars of gas birthing stars, spirals of galactic arms stretching into the void, and clusters of galaxies bending light itself with their gravity.
“As we celebrate Hubble’s 35th anniversary,” reads a recent Presidential Message, “we honor the brilliant scientists, engineers, and visionaries who made such a daring feat possible. Their courage and innovation inspire us all to take risks, dream big, and forge new paths into the unknown.”
Hubble Space Telescope Keeps Evolving
Launched before the birth of today’s youngest astronomers, Hubble remains a vital part of modern astrophysics.
Sam Cutler, a Ph.D. student in astronomy at the University of Massachusetts Amherst, has worked with Hubble data throughout his academic career, even contributing to the telescope’s widest near-infrared (NIR) image of the universe. That image was made possible by a clever and innovative technique called Drift And SHift (DASH), which dramatically boosts the telescope’s data collection rate.
“The most surprising thing about being a part of this imaging,” Cutler says, “was how, even 30+ years after launch, we were still learning new ways to utilize Hubble to expand our understanding of the Universe. […] It was a lot of fun to share these results and pitch it as ‘we can teach this old dog new tricks.’”
The DASH method allowed astronomers to collect eight times more NIR data in a single orbit compared to typical observing strategies. This efficiency gives Hubble the power to scan much larger areas of the sky while retaining its signature resolution, which is something ground-based telescopes have long struggled to match.
Read More: How NASA Is Adapting To An Aging Hubble Telescope
JWST and the Hubble Telescope
Pillars of Creation – furnished by NASA. (Image Credit: Mikolaj Niemczewski/Shutterstock)
Even as the James Webb Space Telescope (JWST) captures headlines for its stunning early-universe observations, Hubble still provides critical context and groundwork. That’s especially true for rare or distant galaxies that require both high resolution and wide survey coverage.
“Although [DASH] doesn’t go as deep as something like the Ultra-Deep Field, it covers a lot of on-sky area, which is really important when you’re trying to find very rare things,” says Cutler. “DASH combines the survey area of a ground-based telescope with the depth and spatial resolution of Hubble, which really allows us to find these more distant, massive galaxies that are both rare and faint.”
Hubble, in other words, has become a sort of cosmic scout later in life. It often surveys broad swaths of the universe, flagging intriguing targets for more detailed scrutiny by JWST.
“The two telescopes work really well together,” says Cutler, “with JWST able to go back and answer all the questions we had about these galaxies that were discovered with Hubble.”
This synergy is no accident. In fact, the upcoming Nancy Grace Roman Space Telescope, scheduled for launch in May 2027, is explicitly designed to complement both Hubble and JWST. Roman will offer image quality on par with Hubble but with a field of view 100 times larger, says Cutler, helping accelerate wide-area surveys of the universe.
Read More: 19 Stunning Galaxy Images from the James Webb Space Telescope
Technical Aspects and Hubble’s Missions
(Image Credit: Dima Zel/Shutterstock)
Despite its age, Hubble’s technical specs are still impressive: a 2.4-meter mirror, five main types of science instruments, including a suite of spectrographs and cameras that have been upgraded through five astronaut-serviced missions. But its most enduring contribution may be the culture it created around open data, long-term research, and collaboration.
The Hubble Legacy Archive has amassed more than 160 terabytes of data, freely available to the global scientific community. This treasure trove from over a million Hubble observations has led to the publication of more than 21,000 scientific papers.
“To have been able to work with Hubble data and use this abundance of knowledge that generations of astronomers have passed down, it really makes me appreciate all the work that has gone into that,” says Cutler. “It also makes me hopeful that one day the tips I’ve learned about JWST and the months of head scratching won’t be in vain, and a future grad student will be able to use them in their research someday!”
Hubble’s Lifespan and Beyond
Hubble’s longevity is itself a scientific marvel. Designed for a roughly 15-year mission, the telescope has more than doubled that lifespan, continuing to operate despite aging components and the end of crewed servicing missions in 2009. NASA and ESA engineers have kept it going through remote upgrades, software patches, and careful planning around equipment failures.
From mapping dark matter to refining the Hubble Constant, the rate at which the universe expands, the Hubble Space Telescope has been central to some of the most transformative discoveries of the past half-century. And as it marks 35 years in space, it remains an enduring symbol of both scientific ambition and engineering excellence.
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Jake Parks is a freelance writer and editor who specializes in covering science news. He has previously written for Astronomy magazine, Discover Magazine, The Ohio State University, the University of Wisconson-Madison, and more.
