Immediately after World War II, the
idea of observing from a telescope in space was initiated by a researcher and
professor at Yale University in 1946. Lyman Spitzer explained the benefits of
having such an instrument in space rather than on ground. His argument in
support of this idea is evident in his paper, “Astronomical Advantages of an
Extra-Terrestrial Observatory”. He states the drawbacks of a telescope such as
the inability to accurately see the light being produced by the stars due to
Earth’s atmosphere which causes it to be blurred and distorted. In addition,
the earth’s atmosphere does allow the x-rays of stars and other celestial
objects with high temperature to be identified. However, Spritzer argued that a
space telescope would permit such observations.
It was not until 1990, the space
telescope named Hubble Space Telescope was launched. With the support from the
National Academy of Sciences in America (NASA), the project began in 1969. The
delivery of the Hubble Space Telescope was delayed as a result of lack of funding
from NASA after the lunar landing. The initial plans for the space telescope
was altered by reducing the quantity of instruments, the size of the primary
mirror and amount of spare parts. The design was specified to perform certain
demands such being able to observe x-rays emitted from stars. The Hubble Space
Telescope will enable scientists to observe a variety of wavelengths emitted
from extraterrestrial objects without the diffusion of any wavelengths by Earth’s
atmosphere. There was no clear single objective for the telescope apart from
benefiting astronomers and scientists to observer the universe from another
perspective and enable mankind to explore.
The Hubble Space Telescope would be
launched into Earth’s orbit and remain there, where it will be able to record
data without any interference from Earth’s atmosphere. The Hubble Space
Telescope works by directing any forms of light, for example gamma rays, x-rays,
and infrared through its lenses into sensors on board. After the light enters
the Telescope the light is redirected by the main lens to the secondary lens
that focuses the light source into the sensor. With the use of the extensive
sensors scientists would be able to observe clear images in different wavelengths.
The Hubble Space Telescope faced a
variety of difficulties when attempting to launch the telescope. Apart from the
numerous delays the Hubble was launched on board the Discovery on April 24,
1990. The Hubble’s equipment’s consisted of the High Speed Photometer, Faint
Object Spectograph, Faint Object Camera, Goddard High Resolution Spectograph,
and the Wide Field/Planetary Camera. Following the launch of the telescope
scientists began to notice slight distortions in the images sent back from the
telescope. Even though the images delivered were clear enough for scientist to
still study, they were not meeting their initial expectations. It was later
discovered through investigations that the primary mirror had a spherical
aberration, meaning that the edges of the mirror were flatter than they were
supposed to be. Following the discovery of the flaw scientists were able to conceive
a way to fix the problem by designing the Corrective Optics Space Telescope
Axial Replacement. The COSTAR would fix the aberration by using multiple
optics. A crew of astronauts were sent on a service mission to repair the
Hubble in December 1993. The crew installed the COSTAR and also replaced the
Wide Field/Planetary Camera with a new one that would compensate the problem
caused by the mirror.
The Hubble Space Telescope has
provided astronomers and scientists access to a great deal of images of the
universe never seen before. The current state of the Hubble Space Telescope is
in jeopardy due to the risks involved with servicing and maintaining the
telescope along with the funds required. This risks involved have been
displayed in the tragedy that occurred in 2003 when seven astronauts died
during the reentry into the atmosphere which resulted in the administrative decision
that all future missions will only be to the International Space Station.
Eventually the Hubble Space Telescope will be retired by NASA and will fall off
orbit towards Earth ending its journey.
The Hubble Space Telescope has
contributed to the advancement of space exploration in the past years. One of
these great observations that was provided by the observatory include, enabling
scientists to observe galaxies that existed when the universe was only a
billion years old. This was done by directing the telescope at an empty part of
the sky for approximately 10 days. Although this was considered risky for the astronomers
since they could be using the telescope for other research it ended up paying
off. The image showed scientists over 3000 galaxies all shaped differently and
was named the Hubble Deep Field. This method of observation was later used
several times to continue to observe the initial galaxies in the universe and
provide an insight into the early stages of the universe.
Another observation that the Hubble
provided was images of Jupiter before and after a collision with a comet. The
Hubble Space Telescope would allow scientists to observer the effects the comet
collision has on Jupiter, how it affects the atmosphere and any changes of its
satellites. With the use of the Hubble astronomers will be able study the
impact more in-depth by being able to observer different spectrums and observe
any variations which would have been not seen in the visible light.
Another breakthrough made possible by
the Hubble Space Telescope was the discovery of organic molecules. The Hubble
was able to detect methane molecules in the atmosphere of a planet orbiting
another star. This is a significant breakthrough since it proves to astronomers
that with the use of spectroscopy, space telescopes will be able to observe
organic molecules in planets in different solar systems. This will enable
scientists to search for planets in the habitable zone with prospects of life
using space telescopes. It also provides scientists to be able to examine
conditions such as temperature using spectroscopy.
Reference
http://www.nasa.gov/sites/default/files/images/345535main_hubble1997_hi.jpg
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