Optics in Space

The Hubble Space Telescope

Alex M.

About the Hubble Space Telescope

The Hubble Space Telescope was launched in 1990. It's a telescope that orbits the Earth and takes pictures of the many parts of space that are 5 times better than any ground telescope.[1] It's positioned above the atmosphere; this distorts and blocks the light that reaches our planet. According to the ESA (European Space Agency) (2010) it is one of the most successful telescopes and long-lasting science missions ever. It also was noted the first major optical telescope to be placed in space (Robert Garner, 2010).[2] Some things that it has helped discover is the age of the universe, the identity of quasars, and the existence of dark energy. It also helped discover many other galaxies and how they grow. This has helped many scientists learn more about the universe outside our own world. It's mission is to orbit Earth and look into space capturing many pictures that are then sent back to the Hubble's main laboratory to develop the photos. The Hubble Space Telescope was named after Edwin Powell Hubble, a great pioneer of modern astronomy. This telescope took $400 to $500 million dollars from the federal government.[3] But it has paid off with all of its discoveries. With the help of the the Hubble telescope's discoveries society will change their look on space. The images captured will show people what space looks like beyond their normal telescopes. It will help people learn more about the universe and what it holds in store.

Design of Hubble

Hubble is a large machine that is built for capturing pictures in space. First there is a primary mirror (2.4m) and a group of science instruments (5) that work across the optical spectrum, which allows them to work in space. It is equipped with cameras, spectrographs, and guidance sensors. According to the Space Telescope Science Institute, the “Light hits the primary mirror, is reflected onto the secondary mirror and from there passes through a small opening in the primary mirror to the focal plane. The focal plane is the size and shape of a dinner plate and is shared by the scientific instruments which sample light and record the information”.[4] This is very helpful in the scientific society with what needs to be known about space.

External Hubble Telescope
Pinwheel Galaxy

How Hubble Captures Images

Light rays from the sun and nearby stars reflects off many different areas in space and then go into Hubble in two separate rays of light. From there the rays go towards the concave primary mirror and then reflect off mirror and then the reflected rays reflect onto the convex secondary mirror. The rays then reflect and narrow off the secondary mirror into a hole in the middle of the primary mirror, that then moves into the part of Hubble where all the camera instruments are. This is where the images are captured and produced. The pictures after being captured are then sent back to the headquarters of Hubble, where they are developed and then shared to the public and researched by scientists.

Simple Ray Diagram of The Hubble Space Telescope BY: Alex Molyneaux

Why the Hubble Telescope is in Space

The telescope is in space because of two main reasons: urban light pollution and refraction in the Earth's atmosphere. The first reason is, urban light pollution is caused by the human population on Earth. We litter the atmosphere with light which then takes away our ability to see stars and other astronomy.[5] The light form buildings, spotlights, arenas and much more fills the sky with all this light, blocking out the stars in the night sky. If the Hubble telescope was on Earth trying to take photos of space there would be too much light pollution reflecting into the sky. The other reason is, refraction in the Earth's atmosphere. This is a reason because when light passes through the Earth's atmosphere some light refracts back into space so that the Earth does not get the full power of the sun. This would affect the the telescope if it were on Earth instead of in space because the telescope would not get the right amount of light reflecting off the planets and stars to capture a clear image of them.


Dark Energy: a force that causes the expansion of the universe to accelerate
Quasar: one of over a thousand known extra galactic objects, starlike inappearance and having spectra with characteristically largeredshifts, that are thought to be the most distant and mostluminous objects in the universe.
Spectrograph: a spectroscope for photographing or producing are presentation of a spectrum.


  1. ^ European Space Agency. (2010). About Hubble. Retrieved May 23, 2012 from: http://spacetelescope.org/about/
  2. ^ Garner, Robert. (2010). Hubble Space Telescope. Retrieved May 23, 2012 from http://www.nasa.gov/mission_pages/hubble/story/index.html
  3. ^ Okolski, Gabriel. (2008). A Brief History of the Hubble Telescope. Retrieved May 23, 2012 from http://history.nasa.gov/hubble/index.html
  4. ^ Space Telescope Science Institute. (2010). The Telescope: Hubble Essentials. Retrieved May 23, 2012 from: http://hubblesite.org/
  5. ^ Journal of Geophysical Research. (2011). Urban light pollution and its impact on nocturnal activity. Retrieved May 26, 2012 from: http://cordis.europa.eu/fetch?CALLER=EN_NEWS&ACTION=D&RCN=33978