Huble Telescope

Hubble is a robotic telescope installed at the outer edges of the atmosphere, in a circular orbit around the Earth, 593 km above sea level.

The orbital period of Hubble Space Telescope is between 96 and 97 minutes.

It was launched into orbit on April 24, 1990 as a joint project of NASA and ESA. It moves at a speed of 28,000 km / hour.

Discovery
The Space Shuttle Discovery on it’s way to space with the Hubble Space Telescope (April 24, 1990). Image: ESA/Hubble (SpaceTelescope.org)

Due to the multiple discoveries of it, the Hubble Space Telescope is known throughout the world.

The Hubble Space Telescope, named in honor of the American astronomer Edwin Hubble.

Hubble
Studio Portrait of Edwin Hubble in 1931. Credit: Wikipedia. Photographer: Johan Hagemeyer.

Hubble technical details

The unit is cylindrical in shape, has a length of 13.20 m and a maximum diameter of 4.20 m; it weighs almost 11 tons.

The cost amounted (in 1990) to 2 billion dollars.

The telescope is a reflector system with two mirrors, the largest of which has a diameter of 240 cm.

For the exploration of the sky it incorporates several spectrometers and three cameras:

  • one with a narrow field to photograph small areas of space (with a weak brightness due to its distance);
  • the second, wide field, to obtain images of planets;
  • and the third is an infrared camera.

Two solar panels are used to generate the electricity that powers the cameras, the four motors used to orient and stabilize the telescope and the cooling equipment for the infrared camera and the spectrometer (both work at -180 ° C).

The Hubble computer system contains a database with the detailed position of 15 million stars, allowing it to point its targets with great precision.

Hubble optical system repair

Initially a failure in the polishing of the telescope’s primary mirror produced slightly out of focus images.

The first mission sent into space to provide technical maintenance service to the telescope, was able to install an optical correction system for the primary mirror and, as a result, it was possible to achieve the resolution specifications initially planned.

Repearing Hubble
The first servicing mission to the Hubble Space Telescope saw astronauts install a set of specialized lenses to correct the flawed main mirror in the telescope. Credits: NASA

Hubble’s sophisticated camera has created a mosaic of images of a large section of the sky, including at least 10,000 galaxies.

With it, approximately one million objects have been observed, obtaining about 500,000 photographs.

Hubble orbit corrections

Due to the friction with the atmosphere (very tenuous at that height), the telescope is losing speed very slowly.

At the same time, the Hubble is gaining gravitational attraction.

Therefore, on each visit, it has been pushed to a slightly higher orbit in order to keep it in the initial orbit.

The sixth maintenance mission was carried out in May 2009.

The crew consisted of seven astronauts. With the arrangements made, Hubble is expected to reach the end of its useful life by 2010-2015.

The exact date of the end of Hubble is uncertain, since it depends on the life of the gyroscopes and the batteries.

Main discoveries made thanks to Hubble.

Thanks to images captured by the Hubble Space Telescope, astronomers have made important discoveries:

  • Star birth in the Eagle Nebula.
  • Stunning images of Comet Shoemaker-Levy 9’s collision with Jupiter in 1994.
  • Images of the expanding universe, which have provided evidence for the existence of dark matter in the universe.
  • The theory that most galaxies host a black hole at their core has been partially confirmed by numerous observations.
  • It has made the first galaxies that formed visible.
  • It has made it possible to detect helium in intergalactic space (possibly originating from the Big Bang).
  • First images showing galaxies with quasars inside.
  • It has detected UV laser emission in space for the first time.
  • It has made it possible to invent a new type of cross-shaped gravitational lens that could be used.

    Hubble Telescope
    Hubble in free orbit. Credit: ESA.

Hubble’s great contribution to Astronomy

Hubble Space Telescope has been one of the projects that have contributed the most to space discovery and technological development in the entire History of Humanity, until now.

Much of the scientific knowledge that scholars have of interstellar space is due to the Hubble Telescope.

Astronomers from more than 45 countries have published thousands of scientific papers about the Hubble discoveries.

Hubble’s Deep Field camera photographed in 1995 a region the size of one thirty millionth of the area of ​​the sky, containing several thousand galaxies.

A similar image of the southern hemisphere was taken in 1998 showing remarkable similarities between the two.

This similarity has reinforced the theory that the structure of the Universe is the same everywhere, regardless of the direction in which look.

Astronomers from more than 45 countries have published thousands of scientific papers about the Hubble discoveries.