Transcript The Hubble Space Telescope (HST)

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 telescopes on
the ground blurry and distorted, no matter how large
or scientifically advanced those telescopes are.
Why? (2)
The second problem ground 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.
The On-Board Tools
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.
Where
Most 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_wo
rldbook.html
HubbleSite. The Telescope: Hubble Essentials.
Retrieved November 2, 2009 from:
http://hubblesite.org/the_telescope/hubble_essentials
/