Hubble Space Telescope

Hubble is a big tool in space.

It stays high above the Earth. This helps it take very clear pictures. The air on Earth can make stars look blurry.

In space, the view is much better. A big mirror helps it see far away. Astronauts even went to space to fix it. Now, it still helps us see the stars.

The Hubble Space Telescope is a big tool in space.

It orbits high above the Earth. This helps it take very clear pictures. On Earth, the air can make stars look blurry. This happens because of air movement. In space, there is no air to get in the way. Hubble can see light that Earth's air blocks. This includes ultraviolet light and near-infrared light.

Hubble is named after a famous astronomer named Edwin Hubble.

The telescope has a large mirror to collect light. When it first launched in 1990, the mirror was not shaped right. This made the images blurry. Luckily, astronauts could visit the telescope to fix it.

This is special because Hubble was made to be repaired in space. Five shuttle missions helped fix and upgrade its parts. These missions replaced its main tools. Hubble has worked for over 30 years. It may work until the year 2040.

The Hubble Space Telescope is a huge tool for studying the stars.

It orbits high above the Earth in a path called low Earth orbit. This special place is very important for science. On the ground, the Earth's atmosphere can make stars look like they are twinkling. This happens because moving air distorts the light. In space, there is no air to get in the way. This allows Hubble to take very sharp, high-resolution images. It also sees light that the air usually blocks.

Hubble works by using a large mirror to collect light from space.

It is a special type called a Cassegrain reflector. This design uses two curved mirrors to focus light. The telescope has five main instruments to help it see. These tools look at ultraviolet, visible, and near-infrared light. Ultraviolet light has very short waves. Near-infrared light has longer waves than what we see. By looking at these different types of light, Hubble can see many secrets of the universe.

Many people worked hard to make Hubble a reality.

Astronomer Lyman Spitzer wrote about the benefits of a space telescope in 1946. Nancy Grace Roman was also very important. She was known as the "Mother of Hubble." She spoke to many people to get support for the project. The telescope is named after Edwin Hubble. He was a famous astronomer who helped prove the universe is expanding.

Building Hubble was a long and difficult job.

NASA and the European Space Agency worked together to build it. The telescope was finally launched in 1990 on the STS-31 mission. At first, the main mirror was ground to the wrong shape. This caused a problem called spherical aberration. This mistake made the images look blurry. Luckily, astronauts fixed the optics during a mission in 1993.

Five shuttle missions helped repair and upgrade the telescope over many years.

Hubble is part of a group called NASA's Great Observatories. Other telescopes in this group look at different kinds of light. For example, the Chandra X-ray Observatory looks at X-rays. The Spitzer Space Telescope looks at infrared light. Hubble has been working for over 30 years now. It reached this milestone in April 2020. Scientists think it might keep working until 2030 or even 2040. A new telescope called the James Webb Space Telescope is now helping to follow in its footsteps.

The Hubble Space Telescope (HST) is a premier space-based observatory located in low Earth orbit.

It serves as a vital research tool for astronomers worldwide. The telescope is one of NASA's Great Observatories. This program includes other specialized telescopes like the Chandra X-ray Observatory and the Spitzer Space Telescope. While Spitzer focuses on infrared bands, Hubble observes the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum.

This wide range of observation allows scientists to study many different cosmic phenomena.

Hubble operates by capturing light that would otherwise be distorted by Earth's atmosphere. On the ground, atmospheric turbulence causes stars to twinkle, a phenomenon known as seeing. This turbulence limits the angular resolution of ground-based telescopes. In space, Hubble is limited only by diffraction. This allows for extremely high-resolution images with very low background light.

The telescope uses a Cassegrain reflector of Ritchey–Chrétien design. This system employs two hyperbolic mirrors to focus light. These mirrors must be incredibly precise to work correctly. The telescope's primary mirror was designed to be polished to an accuracy of 10 nanometers. This is only about 1/65 of the wavelength of red light.

To maintain its mission, Hubble was designed to be serviced by astronauts. This was a unique feature of its construction. Five Space Shuttle missions were sent to repair and upgrade the telescope. These missions replaced all five of the main instruments.

One mission in 1993, STS-61, was especially critical. It corrected a major flaw in the telescope's optics. This flaw was called spherical aberration. It happened because the main mirror had been ground incorrectly. Without this servicing mission, the telescope's scientific capabilities would have been compromised.

The history of the project began decades before its 1990 launch.

In 1946, astronomer Lyman Spitzer published a paper about the advantages of an extraterrestrial observatory. He argued that space would allow for better resolution and the ability to see ultraviolet light. Later, Nancy Grace Roman, known as the "Mother of Hubble," advocated for the project. She served as the program scientist and worked to secure funding from Congress. The telescope was eventually named after Edwin Hubble. He was an astronomer who helped confirm that the universe is expanding.

Building the telescope was a complex and expensive process. NASA and the European Space Agency (ESA) collaborated on the project. ESA provided funding, solar cells, and one of the first instruments.

Funding was often difficult to secure. In 1974, Congress actually deleted all funding for the project. Astronomers had to organize massive lobbying and letter-writing campaigns to win it back. These budget struggles even changed the design of the telescope. The mirror diameter was reduced from 3 meters to 2.4 meters to save money. This change allowed for a more compact configuration of the hardware.

Hubble's scientific impact has been massive and measurable. It has helped determine the rate of expansion of the universe. The telescope has been in operation for over 30 years, reaching that milestone in April 2020. Scientists predict it may continue to function until 2030 or even 2040. It has provided some of the most detailed visible light images ever recorded. These images allow for a deep view into the history of space. Its data is processed by the Space Telescope Science Institute (STScI). Meanwhile, the Goddard Space Flight Center (GSFC) maintains control of the spacecraft.

Today, Hubble is part of a new era of space observation. It is being succeeded by the James Webb Space Telescope (JWST).

The JWST was launched on December 25, 2021, to cover mid-infrared to visible bands. Another successor, the Nancy Grace Roman Space Telescope, is expected to follow in 2027. Hubble remains a cornerstone of astrophysics. It connects our understanding of light, physics, and the history of the cosmos. Even as new telescopes launch, Hubble's legacy of discovery continues to shape how we see the universe.