What is Hubble Space Telescope?

NASA’s Hubble Space Telescope is the first astronomical observatory placed into orbit around Earth with the ability to record images in wavelengths of light spanning from ultraviolet to near-infrared. Hubble continues to operate high above the blurring effects of Earth’s atmosphere.

  • Hubble was launched on April 24, 1990, in the cargo bay of Space Shuttle Discovery and deployed the following day.
  • Hubble continues to provide images of unprecedented resolution from which many new and exciting discoveries have been made.
  • Hubble is a Cassegrain reflector telescope.
  • Hubble orbits about 350 miles (560 kilometers) above Earth’s surface​.
  • The spacecraft completes 15 orbits per day – approximately one every 95 minutes.

Nation United States of America (USA)
Objective(s) Earth's Orbit
Spacecraft Hubble Space Telescope
Spacecraft Mass 24,500 pounds (11,100 kilograms)
Mission Design and Management NASA
Launch Vehicle Space Shuttle Discovery (STS-31)
Launch Date and Time April 24, 1990 | 11:34 UT
Launch Site Kennedy Space Center, Fla. (USA)
Scientific Instruments Current Instruments:
1. Wide Field Camera 3 (WFC3)
2. Cosmic Origins Spectrograph (COS)
3. Advanced Camera for Surveys (ACS)
4. Space Telescope Imaging Spectrograph (STIS)
5. Near Infrared Camera and Multi-object Spectrometer. (NICMOS-not operational)
6. Fine Guidance Sensors (FGS)

Former Instruments:
1. Faint Object Camera (FOC)
2. Wide Field and Planetary Camera 2 (WFPC2)
3. Corrective Optics Space Telescope Axial Replacement (COSTAR)
4. Wide Field and Planetary Camera 1 (WFPC1)
5. Faint Object Spectrograph (FOS)
6. Goddard High Resolution Spectrograph (GHRS)
7. High Speed Photometer (HSP)


  • First telescope designed to be repaired in space

Key Dates

April 24, 1990: Launch

April 25, 1990: Deployment from Space Shuttle Discovery

May 20, 1990: First image, Star cluster NGC 3532

December 1993: Servicing Mission 1 (STS-61)

February 1997: Servicing Mission 2 (STS-82)

December 1999: Servicing Mission 3A (STS-103)

February 2002: Servicing Mission 3B (STS-109)

May 2009: Servicing Mission 4 (STS-125)

A 3D model of NASA's Hubble Space Telescope Credit: NASA Visualization Technology Applications and Development (VTAD) › Download Options

In Depth: Hubble Space Telescope

The Hubble Space Telescope's launch and deployment in April 1990 marked the most significant advancement in astronomy since Galileo's telescope. ​The first major optical telescope to be placed in space, Hubble operates from the ultimate mountaintop. Far above the distortion of Earth's atmosphere, clouds and light pollution, Hubble has an unobstructed view of the universe.

Hubble can see far more than what we can with our eyes. Its domain extends from the ultraviolet, through the visible, and to the near-infrared.

The telescope has had a major impact on every area of astronomy, from the solar system to objects at the edge of the universe. Scientists have used Hubble to observe the most distant stars and galaxies as well as the planets in our solar system.

Data and from the orbiting telescope are the backbone of more than 15,000 technical papers. It also, of course, continues to dazzle us with stunning pictures of stars, galaxies and planets.

Hubble gave us one of the most memorable and important images in human history: the Hubble Deep Field image which shows thousands of galaxies in just a tiny speck of sky.

Hubble has operated far beyond its planned lifetime, but it has needed some repair work.

Shortly after Hubble Space Telescope was deployed in 1990, the observatory's primary mirror was discovered to have an aberration that affected the clarity of the telescope's early images.

Fortunately, Hubble was the first telescope designed to be visited in space by astronauts to perform repairs, replace parts, and update its technology with new instruments. Astronauts repaired Hubble in December 1993.

Including that trip, there were five astronaut servicing missions to Hubble.

Since its fifth and final repair mission in 2009, the telescope has made over 1.4 million observations, located distant swirling galaxies and plotted pockets of dark matter.

Analysis of Hubble’s images even helped earned scientists the Nobel Prize in 2011 for discovering that the rate that our universe is rapidly accelerating.

In short, when Earth has questions, Hubble answers.

Key Resources

NASA: Hubble
Space Science Telescope Institute: Hubble
National Space Science Data Center Master Catalog: Hubble

Hubble Space Telescope News