In 1608, the Dutch lens maker Hans Lippershey tried to bring the distance closer by placing another lens in front of a lens, and this is how the telescope came to be. But Galileo Galilee showed the appropriate way to use it in space research. Over time, telescopes have become not only the main instrument in space research, but also an essential tool. Looking from history to the present, we can see that with the passage of time, its importance has increased with the touch of modernity and sophistication in the telescope. The location of the telescope is not only confined to the space enthusiast's house, laboratory or observatory, but today it also travels in space under different names, shapes and characteristics. Today we will discuss the groundbreaking Hubble Space Telescope, the first telescope to make history and start a new chapter in space exploration.
In
1923, Hungarian scientist Hermann Oberth, American physicist Robert Goddard,
and Russian engineer Konstantino Tsiolkovsky, in their book 'The Rocket in
Planetary Space', expressed first the rocket launch into space with a
telescope. According to them, just as it is difficult to see the outside world
from under water, similarly it is never possible to see the space clearly from
the Earth's atmosphere. In his research paper, published in 1946, the American
physicist Lyman Spitzer talked about the two advantages of a telescope orbiting
in space. The first is the clear visibility of these telescopes and the second
is to more accurately determine the presence of many other types of
electromagnetic waves outside of visible light.
At
the time we are talking about here, the two countries had the most space
research in the world, or it could be said that there was an unwritten rivalry
between them in space exploration due to the Cold War. One was that the United
States and its warring rivals was the then Soviet Union or present day Russia.
A resolution to this effect was adopted by the US Congress in 1962, the
committee was formed in 1965, and in 1968 the US space agency NASA adopted a
preliminary plan for the space telescope. It was decided that NASA and the
European Space Agency would jointly work on this ambitious plan, although the
majority share of the responsibility for this project would remain with NASA.
Different
agencies were then assigned different responsibilities of the telescope. The
Marshall Space Flight Center is tasked with designing the telescope, the
Goddard Space Flight Center is tasked with building the scientific instrument
control of the telescope, Lockheed Martin is assigned with designing the
telescope-friendly spacecraft, the code along with computer of the telescope is
assigned to the Rockwell Autonetics, Perkin-Elmer Corporation is responsible
for making the mirrors of telescope, etc.
Although
the most important part of this telescope is its mirror, but perhaps the
biggest blow of financial inadequacy fell on it. In the initial design, its
diameter was 3 meter, but in the workplace, its diameter was reduced to 2.4
meter. This mirror was the hardest work to make but its initial work started in
1979 and ended in late 1981. The mirror is then covered with a reflective
coating of Aluminum and Magnesium fluoride with a thickness of 65 nanometer and
125 nanometer respectively. (1 nanometer = 10,00,000 millimeter)
Making
the spacecraft for telescope, like this mirror, was also quite a difficult
task. Staying in direct sunlight will cause intense heat in the spacecraft,
while moving in the shadow of the Earth will cause the temperature to drop and
cause severe cold. This reversal will cause the spacecraft to suffer in stress
and as a result, the spacecraft may explode into pieces. So the body of the
spacecraft was covered with several layers of Aluminum coating and some other heat
insulation measures were taken along with it. The spacecraft was built in such
a way that astronauts could go into space, if needed, and periodically replace
and modify different parts of the telescope to keep it in active for a longer
period of time. The telescope has two computers with three additional central
processing units called NASA Standard Spacecraft Computer (NSSC). There are
also two additional same types of computers that can be used to work with other
computers if there is a problem with one.
In
addition to mirrors, computers and sensors, the spacecraft of this telescope
has basically five instruments. Their names are Wide Field and Planetary
Camera, Goddard High Resolution Spectrography, High Speed Photometer, Faint
Object Camera and Faint Object Spectrography. The first device, worked at visible
light, was built by Jet Propulsion Laboratory. The second is made by the
Goddard Space Flight Center and its field is ultraviolet rays, the third
instrument was manufactured by the University of Wisconsin-Madison, this
instrument works in both visible and ultraviolet rays. The European Space
Agency manufactured the fourth instrument and its field of work is ultraviolet
rays. The last device, built by the University of California and Martin
Marriott, is performed on ultraviolet rays. Telescopes also have instruments
that work with infrared rays.
When
the telescope was built as planned and completed, it was found that it has two
mirrors inside; the primary mirror is 2.4 meter in diameter and weighed 828 Kg.
The secondary mirror is 0.3 m in diameter and weighs 12.3 Kg. The spacecraft of
this telescope has 6 nickel-hydrogen batteries. It has two 25-foot-long solar
panels that can generate 5,500 watt of electricity. The electricity consumption
is 2,100 watt. The total length of the telescope is 13.2 meter and its overall
weight is 10,886 Kg.
The
Space Telescope Science Institute is responsible for the scientific work and
data collection of this telescope. The organization is run by the Association
of Universities for Research in Astronomy which is made up of 47 universities
in the United States and 3 international organizations around the world. The
research institutional centre of this second institute is located at Johns
Hopkins University in Baltimore, Maryland, USA. The European Space Astronomy
Centre is its affiliate in Europe.
The
telescope is named after honor of Edwin Hubble. Edwin Hubble was one of the
best astronomers of the twentieth century. At first, the telescope was
scheduled to be launched in 1983 but due to financial crisis and some technical
hurdles, it was postponed to 1986. Just as the launch of the Hubble Telescope
was about to take place in October of that particular year, the Challenger
spacecraft exploded just 73 second after the launch on 24th January of that
year, like a thunderbolt without clouds. A total of seven astronauts, including
two women, were killed and the launch of the Hubble Telescope was postponed
indefinitely.
On
the one hand NASA benefited from the postponement of the launch of the Hubble
Telescope, as a result of which NASA became more aware of the launch, took some
urgent steps, and the software used to communicate with the Hubble Telescope
from Earth was perfected. On the other hand, it is also true that it had cost
NASA 3,00,000 dollar everyday to maintain the Hubble Telescope with the utmost
care.
When
all seemed normal, it was decided that the task of completing this ambitious
mission would be given to the Discovery spacecraft. This was the 31st mission
of the Space Transport System (STS-31). On 24th April 1990, the Discovery
spacecraft, led by Commander Lauren J. Shriver, placed the telescope at the
average of 547 km above the earth with the angle of 28.5 degree with the
equator of the earth. Since then, the Hubble Telescope has been orbiting the
Earth once every 95 minutes at a speed of 27,300 km per hour. The Hubble
Telescope is currently located 120 km above the International Space Station.
The
Hubble Telescope began its work on 25th April 1990, a day after it reached
space, and sent its first image to Earth on 20th May 1990, the
subject was the NGC-3532 constellation, 1,321 light-years away from Earth. But
the picture was not as clear as it should have been. Scientists tried different
ways to solve this problem, but the problem remained. Although much better than
the Earth's telescope, the image could not avoid the error of blur. Eventually,
scientists realized that despite hundreds of precautions, the problem persisted
because of errors in polishing mirrors during its construction.
That
time became very uncomfortable for scientists because the Hubble Telescope
became a ridiculous and annoying thing in public. Many thought that this
mission had to be abandoned because it was virtually impossible to take a
mirror from Earth and replace it with a defective mirror, just as bringing a
telescope to Earth and repairing it and sending it back into space is a time
consuming and expensive plan. After much deliberation, the scientists
discovered the error of the mirror in an innovative way. Scientists knew that
this was due to the amount of error in the mirror. They decided that the
problem would be solved if a special instrument with the same amount of
opposite defects could be fitted to the telescope. (If the error of the mirror
is +0.01 degree then the error will be kept in that special device -0.01
degree)
It
took more than three years for the Hubble Telescope to rectify this defect of
mirror, but during this time many important pieces of information were
transmitted to Earth by it. In addition to the Hubble Telescope mirrors, a
total of five service missions have been launched so far to solve various
problems at different times. This work lasted for 4 to 10 days and the
astronauts walked in space (Spacewalk) and performed this task with the help of
the robotic arm of the spacecraft.
The
first service mission of the Hubble Telescope was carried out in December 1993,
led by Story Musgrave. Through the Endeavour spacecraft, astronauts went to the
Hubble Telescope and spent 10 days, fixing mirrors and installing processors on
computers. This mission was one of the toughest missions in space. This was
followed by a second service mission in February 1997 through Discovery
spacecraft, which replaced some of the telescopic components and changed the
way it collected information. The third service mission was launched in
December 1999 with this Discovery spacecraft. During this time many changes
were made to the batteries, heat shields, gyroscopes and data storage systems.
The fourth service mission was launched in March 2002 through Columbia
spacecraft.
Then
again there was a serious problem. According to the plan, the fifth service
mission was to be launched in February 2005. But the Colombia spacecraft which
participated in 4th service mission of Hubble telescope service mission in
2002, returned to earth after completing another mission, destroyed by a
horrific explosion when it entered into the Earth's atmosphere, In this
incident seven astronauts including two women were killed. Among the dead was
Kalpana Chawla, an astronaut of Indian descent. This caused the Hubble
Telescope's service mission to be suspended indefinitely.
Following
this incident, it was decided that the spacecraft would be modified and sent to
the International Space Station first, and then to the Hubble Telescope. After
much deliberation, the Hubble Telescope's service mission was finally approved
in October 2006. The mission will be launched in October 2006 through Atlantis
spacecraft. But due to some technical reasons this mission was suspended at
that time. The mission was finally completed in May 2009, more than seven years
after the fourth service mission. This mission involved changing the battery
and the gyroscope. This is the last service mission sent for the Hubble
Telescope so far. Through these service missions various instruments of the
Hubble Telescope have been replaced at various times such as the Advanced
Camera for Survey, Cosmic Origin Spectrograph, Fine Guidance Sensor, Wide Field
Camera, Space Telescope Imaging Spectrograph, etc. Some of the old instruments
that have been replaced are preserved in museums today.
The
Hubble Telescope has participated in a number of projects over the past three
decades, most notably the Frontier Fields Program which has observed the
Abel-1869 galaxy, 230 crore light-years from Earth. The Deep Fields Initiative
project seeks to understand the basics of galaxy formation. The Cosmic
Evolution Survey project is an attempt to find out the formation and evolution
of galaxies. Probably the Hubble Telescope's largest project, the CANDELS, is
trying to understand the evolution of space, as well as the state of the
universe 100 crore years after the Big Bang. In other words, the important
functions of the Hubble Telescope are to determine the age of the universe, to
determine the extent of the universe, to gather information from the black
hole, to try to determine the initial state of the universe, to determine the
exact size and mass of the Milky Way galaxy, collecting information in our
solar family, finding nearby exoplanets, searching for life in space, and so
on. Some of this work has been done by the Hubble Telescope alone and the rest
has been done by space telescopes and other ground telescopes on Earth. In
addition, Hubble Telescope has given us a lot of information about how the
composite graphite coating of a spacecraft is effective in space, the effects
of radiation on electronic sensors, the behavior of multi-layer thermal
insulation as a result of long-term use in space, and information about
aerospace engineering in low orbit of Earth. (Aerospace Engineering: Engineering
related to design of aircraft, spacecraft, and satellites, missile along with
development, testing and production of them)
Twice
a day, a total of 20 terabytes of data is received by radio antenna of New
Mexico from Hubble Space Telescope and this information is dent to the Space
Telescope Operations Control Center from where it goes to the Goddard Space
Flight Center, and finally stores in the archives of the Space Telescope
Science Institute. Anyone on Earth can use the information of Hubble Telescope.
However, interested person has to apply for it in a specific way. It is true
that only about twenty percent of the people get the opportunity to use that
information due to lack of time as many applications are submitted every day.
Currently, equipments of Hubble Telescope are becoming old; only three out of six gyroscopes are working. The Hubble Telescope was once kept in safe mode for two days after the electronic set, the main camera malfunctioned. On 21st June 2021, the computer of the telescope malfunctioned and it was fixed again about a month later. In addition, the Hubble Telescope is slowly descending towards the Earth. If this trend continues, the Hubble Telescope will land on Earth between 2028 to 2040. However, the date of entry of the telescope in the dense atmosphere of the Earth depends on the influence of the Sun in the upper atmosphere of the Earth. When the telescope lands at high velocity, it can cause a lot of damage, so scientists will try to land the telescope in such a way that it does not cause any loss of life to humans or any other animal. Although the telescope would suffer considerable damage at high temperatures if it landed on Earth, scientists hope that some of the original structure and parts of the original mirror may survive. Scientists have considered two options to avoid this catastrophe. According to the first plan, the telescope would be brought down to the ground by a spacecraft and preserved in a museum. If that is not possible, the second way is to bring it down to earth with a controlled speed. For this, in the last service mission of 2009, necessary equipments were installed in the telescope. However, the Hubble Telescope still has some work to do. So another service mission aimed at it may be launched in this decade.
We do not yet have an alternative to the Hubble Space Telescope. The new James Webb Space Telescope that is being talked about will not work at different electromagnetic waves as the Hubble telescope does. This new telescope will work on infrared rays that are impossible to detect from the Earth. The real alternative to the Hubble Telescope could be the Large Ultra Violet Optical Infrared Survey Telescope (LOVOIR Telescope). The work of making it will start from 2025 and will end in 2035. This telescope can perform in three types of rays (visible rays, ultraviolet rays and infrared rays). This telescope is needed because the Hubble Telescope answers many unsolved questions in astronomy but gives rise to many more. The clues that the Hubble Space Telescope has given us to answer these questions are just a fragment of the history of the vast cosmic structure. Now this time around, we have to sharpen the appropriate weapon to know the true nature of space across all those pieces.
DECLARATION: All The Images Have Been Sourced From Google.
