The Hubble Space Telescope

The orbiting HST has helped astrologists study and broaden their knowledge of other galaxies and celestial bodies.

Launched into orbit in 1990 by NASA, the Hubble Space Telescope (HST) has been providing us with razor-sharp images of celestial bodies and planets for over 20 years. This $1.5 billion dollar telescope’s purpose was to send us back images from space so we can improve our understanding of galaxies, the birth of stars, and distant objects. These images are mainly for scientific studies but many are available for people to see on the Internet. Although it was not the first telescope to be sent into space, it is one of the largest and most versatile of them all. It contains a mirror with a diameter of 14 feet and has the capability of orbiting around the Earth in 97 minutes (top speed of 28, 000 km/h). The HST has the luxury of being above Earth’s atmosphere and therefore is not affected by dust in the air that would otherwise render photos blurry and unfocused.

Oberth’s orbiting telescope

The idea of sending a telescope into space first came up in 1923 when German scientists and one of the founders of rocketry, Hermann Oberth suggested sending a telescope up to space aboard a rocket. This idea was revisited in 1946 when American astrophysicist Lyman Spitzer Jr. wrote a paper proposing a space observatory be built. He would spend the next half-decade of his life working to make this telescope a reality. The HST uses the Ritchey-Chretien Cassegrain optics system for its telescope which would theoretically eliminate spherical aberration while maintaining a maximum field of view. With NASA, ESA, and numerous professional individuals and companies working on the project, the HST was ready for launch in 1986 but had to wait until 1990 after the explosion of the Space Shuttle Challenger just one minute after taking flight.

Also Check out...  9 NASA Facts Everyone Should Know

Companies that helped develop/ build the HST were: Marshall Space Flight Center (for the design, development and construction), Goddard Space Flight Center ( for the design, development, construction, and ground control), Perkin- Elmer Corporation (for assembly, including mirrors and fine guidance sensors) and Lockheed Missiles (for structure and support systems). The HST was named after astronomer Edwin Hubble.

Hubble’s optics

The Hubble Space Telescope relies on many different kinds of light from the electromagnetic spectrum. It’s equipped with many light-detecting instruments including The Wide Field Camera 3 (WFC3), The Cosmic Origins Spectograph (COS), The Advanced Cameras for Surveys (ACS), The Space Telescope Imaging Spectrograph (STIS) and The Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The HST relies on ultraviolet light, visible light and infrared light although most of these are not seen simultaneously. The HST uses these to detect temperature (infrared), stars and galaxies (ultraviolet, visible and near-infrared) and object wavelengths (very sensitive ultraviolet).

It is widely believed that the reason that the HST can capture such sharp images is its ability to magnify. It reality it’s its ability to collect as much light as it can (hence the need for a large mirror) that allows for these images. The HST operates using a Ritchey-Chretien Cassegrain optics system for its telescope, which comprises two mirrors: the primary mirror (larger, concave mirror) and the secondary mirror (smaller, convex mirror). Incident rays travel down the HST’s large tube (which filters out stray light) and down to the primary which helps in converge as they’re refracted towards the secondary mirror. It refracts off of the secondary mirror and back through a hole in the primary mirror, it’s finally collected by the HST’s instruments (which are located behind the primary mirror).

Also Check out...  Observing Ursa Major - the Big Bear & the Big Dipper

Hubble’s Impact

The Hubble Space Telescope has had a profound impact on society’s understanding of what goes on in space. It has impacted the scientific community’s understanding of otherwise unknown/ overlooked occurrences. The HST has made extraordinary discoveries that have changed the way we look at our galaxy and at the universe itself. It was used to prove that the universe is actually expanding at a very quick pace compared to what we had previously thought. It has also offered us visual proof as to how planets are made. It has also discovered many galaxies that were overlooked by astrologists because they were so far away.

Sources:

  • “Cassegrain Reflector.” Wikipedia, the Free Encyclopedia. 2 Sept. 2010. Web. 13 Feb. 2011.
  • “Hubble Space Telescope.” Wikipedia, the Free Encyclopedia. Wikipedia, 24 Nov. 2010. Web. 13 Feb. 2011.
  • “HubbleSite – The Telescope – Nuts & Bolts – Optics.” HubbleSite – Out of the Ordinary…out of This World. Web. 13 Feb. 2011.
  • “James Webb vs Hubble.” NASA – Home. NASA. Web. 13 Feb. 2011.
  • NASA. “HubbleSite – Hubble Essentials – Light Path through Hubble.” HubbleSite – Out of the Ordinary…out of This World. NASA. Web. 13 Feb. 2011.
  • NASA. “HubbleSite – The Telescope – Hubble Essentials – Quick Facts.” HubbleSite – Out of the Ordinary…out of This World. NASA. Web. 13 Feb. 2011.
Categories Space

Leave a Comment