The Hubble Space Telescope (H.S.T.)

By Jason Hunyar

What

The Hubble Space Telescope is a telescope that was launched by NASA in April 24, 1990 aboard the space shuttle Discovery (top left).As soon as the HST was launched, all of the scientists knew they had a problem, the images were slightly blurry.On December 2, 1993 the space shuttle Endeavour (top right) made repairs, including the Corrective Optics Space Telescope Axial Replacement (COSTAR); which fixed the blurriness.

The Beginning (How and When)

In 1923, the idea of a telescope in space, or at least outside Earth’s atmosphere was proposed officially by a man named Hermann Oberth.A man named Lyman Spitzer Jr. (top right) helped encourage NASA to approve the Large Space Telescope project in 1969.In 1974, the group working on the project suggested that the telescope should have interchangeable instruments. The Space Shuttle would be used to get the telescope in orbit and possibly return it to Earth for repairs and replacement instruments, or they would just service it in space.

How (2)

In 1975, the European Space Agency began to work together with NASA on a plan that would eventually become the Hubble Space Telescope. In 1977, Congress approved funding for the telescope.

Diagram of the Hubble Below(1981, Credit: Lockhead Martin Space Systems

company)

Why?

The Hubble Space Telescope is the direct solution to a problem that telescopes have faced since the very earliest days of their invention: the atmosphere. There are two problems with the atmosphere:The first problem that ground telescopes face are shifting air pockets in the Earth's atmosphere. These air pockets make the the view of ground-based telescopes blurry and distorted, no matter how large or scientifically advanced those telescopes are.

Why? (2)

The second problem ground-based telescopes encounter is that the atmosphere also partially blocks or absorbs certain wavelengths of radiation, like ultraviolet, gamma and X-rays, before they can reach Earth. This is a problem for astronomers because scientists can best examine an object like a star by studying it in all the types of wavelengths that it emits, not just visible light. Newer ground-based telescopes are using technological advances to try to correct atmospheric distortion, but there's no way to recreate the missing wavelengths.

Why? (3)

The most effective way to avoid the problems of the atmosphere is to place your telescope beyond it. Or, in Hubble's case, 353 miles (569 km) above the surface of Earth.

*Cool Fact: This "atmospheric distortion" is the reason that

the stars seem to twinkle when you look up at the sky.

On- Board Instruments

The Wide Field Camera 3The Cosmic Origins SpectographThe Advanced Camera for SurveysThe Space Telescope Imaging SpectographThe Near Infrared Camera and Multi-Object SpectrometerThe Fine Guidance Sensors

The WFC3

The Wide Field Camera 3 (WFC3, background) sees three different kinds of light: near-ultraviolet, visible and near-infrared, though not simultaneously. Its resolution and field of view are much greater than that of Hubble's other instruments. WFC3 is one of Hubble's two newest instruments, and will be used to study dark energy and dark matter, the formation of individual stars and the discovery of extremely remote galaxies previously beyond Hubble's vision.

The COS

The Cosmic Origins Spectrograph (COS), Hubble's other new instrument, is a spectrograph that sees only in ultraviolet light. Spectrographs acts something like prisms, separating light from the cosmos into its component colors. This provides a wavelength "fingerprint" of the object being observed, which tells us about its temperature, chemical composition, density, and motion. COS will improve Hubble's ultraviolet sensitivity at least 10 times, and up to 70 times when observing extremely faint objects.

The ACS

The Advanced Camera for Surveys (ACS, top left) sees visible light, and is designed to study some of the earliest activity in the universe. ACS helps map the distribution of dark matter, detects the most distant objects in the universe, searches for massive planets, and studies the evolution of clusters of galaxies. ACS partially stopped working in 2007 due to an electrical short, but was repaired during Servicing Mission 4 in May 2009.

The STIS

The Space Telescope Imaging Spectrograph (STIS, bottom right) is a spectrograph that sees ultraviolet, visible and near-infrared light, and is known for its ability to hunt black holes. While COS works best with small sources of light, such as stars or quasars, STIS can map out larger objects like galaxies. STIS stopped working due to a technical failure on August 3, 2004, but was also repaired during Servicing Mission 4 (top right).

The NICMOS

The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is Hubble's heat sensor. Its sensitivity to infrared light — perceived by humans as heat — lets it observe objects hidden by interstellar dust, like stellar birth sites, and gaze into deepest space.

The FGS

Finally, the Fine Guidance Sensors (FGS) are devices that lock onto "guide stars" and keep Hubble pointed in the right direction. They can be used to precisely measure the distance between stars, and their relative motions.

*Cool Fact: All of Hubble's functions are powered by sunlight. Hubble sports solar arrays that

convert sunlight directly into electricity. Some of that electricity is stored in batteries that

keep the telescope running when it's in Earth's shadow, blocked from the Sun's rays.

WhereMost people think of where the actual

telescope is in space when they think of the HST, but the real

information is on the ground. The Goddard Space Flight Center in

Greenbelt, MD, is the true base of the Hubble Space Telescope. This

is where the images from the telescope itself are relayed down

from multiple satellites to (as shown in the diagram). As soon as the Goddard Space Flight Center receives data from the telescope, they send it to Space Telescope

Science Institute (STScI) where the staff translate the data into

meaningful units. Then the data goes into archives and is enabled to

be downloaded by astronomers anywhere in the world. The HST usually brings in about 18 DVDs worth of information every week.

Non-Visible Light(Why this is important to us)

Using the advanced instrumentation of the Hubble Space Telescope, astronomers have been able to see different types of light, such as ultra violet, that come through space dust, to find out more about the universe. After analyzing these images through the COS, we have been able to find out the composition of stars, galaxies, etc. But while the Hubble Space Telescope looks out through space, it is also looking through time. As the telescopes looks at light that was created x number of light years away, it can see what happened at that place x number of light years ago.For example, if the HST was looking at the light of a star 30,000 light years away, it would be looking at the same light that was created at that star 30,000 light years ago.

Why we should care

As students and citizens, everyone around the world should care about the Hubble Space Telescope. This telescope can unlock

answers about science that today, is beyond our wildest imaginations. This telescope and future telescopes, should be

able to help us find out huge questions in the minds of scientists today; what happened at the beginning of the universe. With all

of these new discoveries, we will definitely by able to make huge advances in science technology and future advances in

the world of astronomy.

As Neil Armstrong once said,

“That’s one small step for man, one giant leap for mankind.”

Source Citations

National Aeronautics and Space Administration (N.A.S.A.).World Book At N.A.S.A.: Hubble Space Telescope.Retrieved October 29, 2009 from:

http://www.nasa.gov/worldbook/hubble_telescope_worldbook.html

HubbleSite. The Telescope: Hubble Essentials. Retrieved November 2, 2009 from:http://hubblesite.org/the_telescope/hubble_essentials/