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Lockheed Hubble Space Telescope

Lockheed · Space Telescope / Earth Orbit Observatory / Optical / UV / Near-IR Astronomy · USA · Modern (1992–2009)

Lockheed Hubble Space Telescope — Space Telescope / Earth Orbit Observatory / Optical / UV / Near-IR Astronomy
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The Hubble Space Telescope is one of the most-productive scientific instruments in history. Built by Lockheed Missiles & Space Company (now Lockheed Martin) for NASA, with optics by Perkin-Elmer (now Raytheon), Hubble was deployed by Space Shuttle Discovery on 25 April 1990 into a 547 km low Earth orbit. As of 2026 the telescope has completed 36 years of continuous science operations, generating over 1.6 million scientific observations and forming the data backbone for more than 18,000 peer-reviewed papers — more than any other single instrument in scientific history.

Hubble is a 2.4-m Cassegrain reflecting telescope optimised for ultraviolet, visible, and near-infrared light. The 11.6-tonne airframe carries six scientific instruments (currently the Wide Field Camera 3, Advanced Camera for Surveys, Cosmic Origins Spectrograph, Space Telescope Imaging Spectrograph, plus two Fine Guidance Sensors). Power comes from twin solar arrays generating 5,500 W; pointing is controlled by reaction wheels and gyroscopes to a precision of 7 milliarcseconds — equivalent to holding a laser pointer steady on a coin from 200 miles away.

Hubble was launched with a mirror flaw — a 2.2-micrometre spherical aberration introduced during grinding by Perkin-Elmer that produced soft, smeared images for the first three years. NASA's Servicing Mission 1 in December 1993 (Space Shuttle Endeavour, STS-61) installed the COSTAR corrective-optics package and replaced the Wide Field/Planetary Camera with WFPC2 — completely fixing the aberration in flight. Four subsequent servicing missions (1997, 1999, 2002, 2009) replaced instruments, gyroscopes, batteries, and computers. The 2009 mission (STS-125) was the final servicing visit; no future repair flights are scheduled.

Hubble's most-famous discoveries include direct imaging of the Hubble Deep Field (a 10-day exposure of "empty" sky that revealed thousands of new galaxies), measurement of the Hubble constant to ~3% precision, the discovery that supermassive black holes sit at the centre of most galaxies, and direct imaging of exoplanet HR 8799 b. As of 2026 Hubble continues to operate with three working gyros and a gradually-degrading reaction-wheel set; NASA expects 5-10 more years of useful life. The telescope will eventually re-enter the atmosphere and burn up, sometime in the 2030s.

For Kids — a shorter, friendlier version

The Hubble Space Telescope is the most famous telescope in the world. It orbits 340 miles above Earth — above all the clouds, dust, and air that blurs the view of telescopes on the ground. From its perfect position, Hubble has taken some of the most-amazing photographs ever of stars, planets, and far-away galaxies.

NASA launched Hubble into space aboard the Space Shuttle Discovery in April 1990. The telescope is about 43 feet long — bigger than a school bus — and weighs 24,500 pounds. At its heart is a giant mirror almost 8 feet across. The mirror reflects starlight onto cameras and instruments inside the telescope.

When Hubble was first turned on, the pictures came back blurry. NASA scientists were shocked — there was something wrong with the mirror. A space shuttle mission in 1993 sent astronauts to install special corrective optics, like "glasses for Hubble." After the fix, the photographs were crystal clear. Without it, Hubble might have been one of the biggest disasters in NASA history.

Since 1990, Hubble has taken more than 1.5 million photographs of the universe. It discovered that the universe is expanding faster than expected. It showed that stars die in beautiful supernova explosions. It captured the famous Pillars of Creation — towers of cosmic gas where new stars are being born.

Hubble is still working in 2026, 36 years after launch. The newer James Webb Space Telescope (launched 2021) sees even more — but the two telescopes work together, looking at the universe in different colors of light.

Fun Facts

  • Hubble orbits 340 miles above Earth — about 11 times higher than a passenger jet flies.
  • Hubble's main mirror is almost 8 feet across — bigger than a doorway.
  • Hubble was launched in 1990 and is still working in 2026 — 36 years in space.
  • Hubble's first photos were blurry — astronauts had to install "glasses" in 1993 to fix the mirror.
  • Hubble has taken more than 1.5 million photographs of stars, planets, and galaxies.
  • Hubble photos have led to more than 18,000 published science papers.
  • Hubble's famous "Pillars of Creation" photo shows giant clouds of gas where new stars are being born — it became one of the most-recognized space pictures ever.

Kids’ Questions

Why is Hubble in space?

Telescopes on the ground have to look up through the Earth's atmosphere — and the atmosphere blurs and dims the starlight. From the ground, even the biggest telescopes see stars as fuzzy points. From space (above the atmosphere), Hubble sees crystal clear. Hubble can also see ultraviolet and infrared light that Earth's atmosphere blocks completely — kinds of light no ground telescope can see at all. Plus, Hubble can observe the same patch of sky for many hours without clouds or weather problems.

Is the James Webb telescope replacing Hubble?

Not exactly — they're partners. The James Webb Space Telescope (launched 2021) is the next-generation telescope, but it sees infrared light (heat). Hubble sees visible light (what our eyes see) plus ultraviolet. Together, they cover much more of the universe than either could alone. NASA hopes to keep Hubble working for as long as possible — maybe through 2035 or longer. The Webb telescope is 1 million miles from Earth, while Hubble is just 340 miles above us. No more astronaut visits are planned, so Hubble will eventually wear out — but for now both keep taking spectacular photos.

Variants

Hubble Space Telescope (sole airframe)
Single instrument deployed by STS-31 (Discovery) on 25 April 1990. 2.4 m primary mirror, 11.6 tonnes. Five servicing missions (1993, 1997, 1999, 2002, 2009) replaced instruments and components.

Notable Operators

NASA
Mission sponsor and lead operator. Mission control at Goddard Space Flight Center, Greenbelt, Maryland. Science operations at the Space Telescope Science Institute (STScI) in Baltimore.
European Space Agency (15% partner)
Co-sponsor at 15% mission share. Provided original solar arrays, the Faint Object Camera (1990-2002 instrument), and continues to receive 15% of observation time for European astronomers.

Frequently Asked Questions

Is Hubble still working?

Yes — as of 2026 the Hubble Space Telescope continues science operations after 36 years in orbit. Three of its six original gyroscopes are still functional; the reaction wheels are degrading slowly. NASA expects 5-10 more years of useful life before atmospheric re-entry sometime in the 2030s.

Why did Hubble's first images look blurry?

The primary mirror was ground with a 2.2-micrometre spherical aberration error — Perkin-Elmer used a slightly mis-calibrated null corrector during grinding. The flaw made all images smeared and soft for the first three years (1990-1993). NASA's Servicing Mission 1 (December 1993) installed the COSTAR corrective-optics package and the WFPC2 camera, completely correcting the aberration in flight.

How many servicing missions did Hubble have?

Five Space Shuttle servicing missions: SM1 (December 1993, STS-61), SM2 (February 1997, STS-82), SM3A (December 1999, STS-103), SM3B (March 2002, STS-109), and SM4 (May 2009, STS-125). SM4 was the final mission; no future servicing flights are planned because the Space Shuttle programme retired in 2011.

Is Hubble being replaced?

The James Webb Space Telescope (JWST, launched December 2021) is Hubble's infrared successor — but Webb works at infrared wavelengths and cannot see ultraviolet or visible light. Hubble remains the only space telescope able to image at UV/optical wavelengths. The proposed Habitable Worlds Observatory (early 2040s) is the eventual UV/optical follow-on.

What did Hubble discover?

Major contributions: measurement of the Hubble constant (universe expansion rate) to ~3% precision; direct evidence that supermassive black holes are at the centre of most galaxies; the Hubble Deep Field and Ultra Deep Field (revealing thousands of distant galaxies in supposedly empty sky); direct imaging of exoplanets; Pluto's surface mapping; Mars dust-storm monitoring; and innumerable measurements of dark matter and dark energy distribution.

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