CAJ 9: The Look into the Future of Space Telescopes/ The James Webb Space Telescope

Now we know about the two famous space telescopes that changed our notion of the Universe and helped many astronomers around the world in analyzing phenomena like the black hole, dark matter, or planets orbiting other stars. But how does the future look for space telescopes. Hubble had already five servicing missions and the Kepler Mission will also only work for maybe this decade and not longer. What will come after that? Considering that the technologies that these telescopes are using are considered to be outdated compared to the  technological advancements already existing, the question occurs what will the future space telescopes be like?

The answer to this question is The James Webb Space Telescope (JWST), or formerly known as The Next Generation Space Telescope (NGST). The Primary funding bodies are the NASA, The European Space Agency (ESA) and the Canadian Space Agency (CSA). Supposedly it will be launched in 2018 (approximately when the Kepler Mission's current mission status is over). It's Mission is to observe the Universe and study its origins and the first galaxies. From the Big Bang to the formation of solar systems and the planets in those solar systems, it will give us insight into the history of our Universe. It will be the successor of Hubble but technologically it will be much more advanced.

The Telescope itself will be enormous in size. Alone the sunshield will approximately be the size of a tennis court. The Mirror of the telescope will be 6.5 meters in diameter. This is nearly three times bigger than that of Hubble (2.4 m). As the size of the sunshield is bigger in width than the rocket used that launches it, the telescope, with its shield will only be unfolded when it has arrived in space.


The observatory itself consists of three main parts. The Integrated Science Instrument Module (ISIM) which is responsible for housing the cameras and the instruments. The Optical Telescope Element (OTE), which is the Eye of the Observatory. It comprises two mirrors one primary and one secondary mirror and a backplane which is the spine of the mirrors. These mirrors collect the sunlight and direct it towards the science instruments. The primary mirror consists of 18 hexagonal parts that are connected to each other and will only unfold when the observatory is in space. The Mirror itself is made of metal beryllium and is coated with gold. The second mirror, similarly like the Hubble Telescope, is reflecting the sunlight collected by the primary mirror and concentrates it towards the science instruments.  The third main part is the spacecraft bus, which is responsible for supporting functions. The six subsystems that keep the telescope functioning are located in the spacecraft bus. The Electrical Power Subsystem, the Attitude Control Subsystem, the Communication Subsystem, the Command and Data Handling Subsystem, the Propulsion Subsystem, and the Thermal Control Subsystem are all essential for the telescope to function properly.

These are only the main parts of the observatory. However, the Telescope consists of many more other elements.

The Telescope observes mainly the infrared light that comes from very distant objects, but by simply functioning, the System itself emits infrared light. For this reason the Spacecraft is also applied with a sunshield that protects it from overheating and from swamping the incoming light with infrared light emitted from the systems of the telescope. 


The already mentioned ISIM will be the heart of the telescope and includes four elements: 

Near-Infrared Camera - primary imager

Near-Infrared Spectrograph - disperses incoming light into a spectrum to analyze

Mid-Infrared Instrument - has both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum

Fine Guidance Sensor - allows the telescope to point precisely All of these systems are the most sophisticated technologies that are currently known. This telescope will help humanity discover things that we do not even know about yet. Maybe even life on another planet. Take care, Harald

PS: Looks like Star Wars is becoming reality huh? :D

CAJ 8: The Hubble Telescope - Optics (part 3)

How is it possible that a telescope can view stars that are more hundred or even thousand light-years away? What optical device is capable of picturing galaxies that are so far away that we cannot even conceive the enormous distances?

It is not only the fact that it does not have to look through our polluted atmosphere, but also the "eyes" of Hubble. The eyes of Hubble have also a real name that is the Optical Telescope Assembly. This system is designed to offer the widest possible field of view. The system consists of two main mirrors, apertures and supporting trusses.

As the light strikes the telescope, it enters the tube, which prevents stray light to enter the telescope. After it entered the tube it passes the first optical glass. Than it strikes the first mirror that is shaped like an upside down bowl. This mirror is called the concave. Because of the shape of the mirror, it diverts the light and reflects it to the centre of the optical glass in which the second convex shaped mirror can be found. This mirror directs the light again to the first mirror. The first mirror has a hole in the Center where the light can enter and can reach its focal point right where the science instruments are placed. This basic model is called the

Ritchey-Chretien Cassegrain. 

The main mirror measures 2.4 meters in diameter. The smaller mirror that redirects the light towards the science instruments is only 0.3 meters in diameter. The focal plane where the light gets picked up is roughly the size of a dinner plate. 

The mirrors are developed in a very special way. They are treated with abrasives so that the surface of the mirrors is perfectly smooth. The mirrors are designed so that they do not deviate from a perfect curve by more than 1/800,000th of an inch. To help you understand this I use an example. The mirrors are so smooth that if the mirror were as big as the Earth in Diameter, the biggest bump would be 6 inches tall. 
The mirrors are made of ultra-low expansion glass and are kept constantly at the same temperature. This prevents the glass from cracking or warping. The surfaces are coated with a very thin layer of aluminum and a similarly thin layer of protecting magnesium-fluoride. The magnesium-fluoride allows the mirrors to be even more reflective to ultraviolet light. 

In the first post I already mentioned the first problems of the telescope with the mirrors and blurry images. This was because of the primary mirror. After the telescope was launched and the first images were sent to Earth, it became apparent that something is wrong with the telescope as the images are all very blurry. This was because the primary mirror had a flaw called spherical aberration. The outer edge of the mirror was four microns flatter than intended. Four microns equal approximately one-fiftieth of a single human hair.

During the first servicing mission this problem was solved by putting small corrective mirrors on the primary mirror. After this the images became much sharper and the telescope could start to function properly. During the fourth servicing mission the corrective mirrors were replaced by an instrument called Cosmic Origins Spectrograph. This device breaks down the light reaching the telescope. By analyzing these light waves, scientists can determine the density and chemical components of a planet. This technology was a major development and improved the telescope's sensitivity up to 10 times, especially the sensitivity to ultra-violet light. 

How instant photographs work

Instant photography is remarkable because it encompasses every individual step of photography, from the actual taking of a photograph to the developing process. The instant camera has basically a built in dark room, where traditionally the photographs are developed. The film in the instant camera is a piece of plastic paper with many layers, containing light-sensitive grains. Every layer reacts to another color. While regular film has only the layers with the light-sensitive grains, instant film contains every necessary chemical substance required for developing the photograph. First there are additional layers of developing chemicals between every light-sensitive layer. These layers are all placed on a base layer or also called black layer.  Above these light-sensitive layers is the image layer the timing layer, the acid layer and a clear plastic layer that covers up the whole picture. The arrangement of the layers is crucial for the chemical reaction to be set in motion. The reagent chemical is the essential component that causes the reaction. It  is  collected in a bulb on the side of the paper. When taking a picture, the light-sensitive layers absorb the light energy. When this happened, the film is pushed through two stainless steel rolls that break the bulb and spreads the reagent across the picture. The reagent is pressed in right between the image layer and the light-sensitive layer. This reagent contains opacifiers and alkali, which both react with the light-sensitive layer and the layers above. It starts the chemical reaction in the light-sensitive layers by changing the particles into metallic silver. Then the particles that were struck by the light, travel up into the image layer. After the film was tossed through the rolls, it comes out of the camera but the image is not visible yet. This is because the chemical reaction has not ended yet. The opacifiers in the reagent allows the film to be exposed to light because it blocks the light from reaching the other layers. The acid layer in reaction with alkali will make the opacifiers become clear. The timing layer is responsible for slowing down the reagent, to give the film enough time to develop. This is the reason why it takes some time until the image becomes visible on the film.

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CAJ 7: The Hubble Space Telescope / The Spacecraft (part 2)

In my last post I introduced the Hubble Space Telescope and its importance for planetary science and humanity in general. In this post I would like to introduce the telescope in somewhat more detail. I will take the Spacecraft apart, to introduce every aspect of this significant apparatus individually.

As Hubble is the first telescope in space, it was a forerunner in every sense. The outer-space conditions are often severe and to achieve the best results possible and to maintain the high performance of the telescope several spacecraft support systems are in place to keep the telescope functioning.  Over the operation time of Hubble, it had experienced many major upgrades to ensure that the telescope is always in compliance with the latest advancements of technology. To introduce the technology behind it, I am going to separate the spacecraft systems according to Housing, Communication, Power, Computers.

The Housing:

The Housing of the telescope is basically the flesh and bones of the Spacecraft. It is the layer that protects it from the severe conditions in space and the skeleton that houses every single instrument. For example, solar winds and  sudden changes in temperature are very frequent conditions that can come very sudden and unexpected. Therefore, the telescope has to be equipped with the appropriate technologies to protect it.

The multi-layered insulation (MSI) on the telescope makes it appear as if it would be covered with Gold. It is a layer that protects the telescope from thermal radiation and dust impacts. The layer consists of many sheets, often with a solid layer, for example beta cloth, which is a fireproof silica fiber cloth.

Another layer of insulation was added during a servicing Mission in 2009. The New Outer Blanket Layers (NOBLs). This layer consists of sixteen thin layers of dimpled aluminized Kapton material that are covered by an outer aluminized Teflon shell. This layer serves to protect the telescope from radiation and prevents the inner systems from overheating by simply reflecting the sun rays.

Under these layers is the Skeleton of the telescope. It is a light-weight aluminum shell that holds the parts together. It houses the optical devices and the supporting instruments.

Power:

The Telescope is powered by sun rays, as it could hardly be connected to Earth. As the telescope has to power radio transmitters, computers and scientific instruments, it requires much electricity. On the side of the tube (optics, main body), two blue solar arrays are installed that are covered in a solar cell blanket. These wing-like arrays convert sunlight into electricity. These arrays are designed to be easily replaced by an astronaut. They can even be folded for shuttle trips.

The telescope has also batteries that ensure that it can operate while it orbits in Earth`s shadow.

Communication:

Hubble receives instructions from the Flight Operations Team at Goddard Space Flight Center in Greenbelt, Md., and it performs the actions according to the instructions. With a very sensitive antenna it can capture the transmitted signs and send the data to Earth. It transmits the collected data to a Tracking and Data Relay System (TDSR) that consists of five satellites. These satellites then transmit the data to Earth. The telescope has to be in line of sight with at least on of the five satellites to transmit and receive information. While it is in line of sight of one satellite, scientist can perform direct changes in the pointing of the telescope and fine tune their observations. 

(As the telescope receives the commands well in advance, this is usually not necessary.)

In case a satellite is not in sight, the telescope has a special data recorder that can store the information until the satellite is in sight again.

Computers and Automation:

In order to run properly, the Hubble Telescope requires many computers and microprocessors.  It is equipped with two main computers that look like the belt that surrounds the main body of the telescope. One of which is responsible for the communication, the receiving and sending of data and forwarding the instructions to the individual instruments. The other main computer runs the gyroscopes, the pointing system, the optical devices (will be explained in another post) and other system-wide functions. There are also additional backup computers that keep Hubble safe in the event of a problem.

There are many more small computers in the individual parts of the telescope that help to collect the data, open and close the exposure shutter,  direct the rotation of the filter wheels and maintain the temperature of the instruments. These smaller computers and microprocessors are all connected to the main computers.

Further posts about the optical devices and how they function will follow.
Take care,
Harald

Zombie Abstract

The purpose of this research paper is to introduce mathematical models that can be applied to any scenario imaginable. The models help to illustrate and calculate any given scenario or possible outcome.  The scope of this paper is to give a detailed equation on how to calculate all the possible results of a disease expanding very fast. In this case the example of a zombie infection is used to demonstrate the dynamic applicability of the models. By incorporating realistic factors and assumptions, the models illustrate the possible outcomes of a zombie apocalypse and also the recommended solutions to avoid the eradication of humanity.  The paper first introduces a basic model, which only works with a limited amount of possibilities. Further models are introduced in which more factors are incorporated and the mathematical possibilities become more and more realistic throughout the paper. It becomes apparent that with these mathematical equations any realistic or even unrealistic scenario can be illustrated and it can be expanded upon unlimited assumptions and factors. These mathematical models are important as they can help to model biological processes or in this case they could help us to develop a strategy for fighting off a zombie infection and prevent a zombie apocalypse from exterminating humanity .This paper reveals the fact that with mathematical analysis anything can be modeled and calculated, therefore dangerous outcomes can be avoided beforehand. 

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CAJ 6 - The Importance of The Hubble Telescope (post 1)

From Greek philosophers to scientists of the Renaissance, all looked up at the sky to find answers for questions yet undiscovered. The Universe and its undiscovered mysteries were always a major source of inspiration and one of the biggest question of humankind.

When in 1990 the NASA launched its first space telescope named Hubble, we came one step closer to the answer of our questions. The launch of the telescope marked the most significant advance in astronomy and planetary science since Galileo directed his telescope to the sky.

Everything began in 1962, when the National Academies of Science put forward a request for developing a space telescope. Only in the 70's did the NASA devote attention to this idea. Bob O'Dell was the first project scientist of the Hubble project, which at time was not even funded. Many years O'Dell worked tirelessly on promoting the idea to the NASA but they did not believe in the feasibility and the advantage of observing our Galaxy outside of our atmosphere. Finally in 1983 the Space Telescope Science Institute was established and seven years later they launched Hubble, the first telescope in space.

As the mirror of the telescope had the wrong shape on the edges, the first pictures appeared blurry. Another problem, which the scientists did not consider, was the shaking of the telescope due to the strong blow of solar winds. Luckily the telescope was designed to be serviceable constantly. Therefore, three years later in 1993 the mirror of the telescope was upgraded and the image appeared sharp. Since then the telescope has been upgraded numerous times and is always kept up-to-date with recent inventions.

The contribution of the Hubble telescope is unquestionable. Many discoveries and  theories emerging from those discoveries can be attributed to it. Hubble provided evidence that the Universe's expansion was accelerating. This was a milestone for physics, as till then scientists believed that it was slowing. This was achieved by observing a dying star. By observing this supernova, scientists could calculate its distance that was much farther away than predicted.
For physics this meant a discovery as important as General Relativity.

Connected to the observation of supernovas, the Hubble telescope also contributed to another big discovery. Dark matter is one of the biggest clues of science. The Hubble Telescope was constantly observing the violent death of stars. The light of these dying stars was spotted and their distance could be calculated. These distances are bigger than expected and without the added force of dark matter, the Universe could not expand so fast.

The Hubble Telescope revealed us how unbelievably complex and beautiful our Universe is. It captured images of Galaxies and dying Stars and phenomenoms that are still unexplained.

More about the importance, discoveries and achievements of the Hubble Telescope will follow.

How to prevent a time-traveling assassinator from killing Hitler

Instructional text

How to prevent a time-traveling assassinator from killing Hitler

what you will need:

- a time-machine

- good negotiation skills

- a gun

- a mega-doses of methamphetamine

Step one:

Acquire a time-machine as the one in the picture below and read the instruction manual carefully.

Step two:

Do some test travels to make sure you know how it works.

Step three:
If you are willing to kill a person that wants to kill another person: buy a gun at the local gun shop and  travel to the time the assassinator was planning his attempt. If the time is right, shoot him in the head with the gun. Mission accomplished.

If you want to prevent the assassinator from killing Hitler without the cost of a human life than you need a more elaborate plan.

Step four:  

Travel to the time when the assassinator was planning his attempt against Hitler and spy on him until you know all the details of his plan.

Step five:

Make up a fake identity and try to convince the assassinator that he should not attempt to kill Hitler. Tell him that you are from the alternative future in which he succeeded in killing Hitler and that the consequences that his early death brought about are very severe.

Step six:

If the assassinator believes you than the mission is accomplished and you can travel back to your time.

If he does not believe you, then set your time machine for the date when Hitler was still alive,  three days before the planned assassination.

Step seven:

Tell Hitler everything about the planned assassination and advise him to go into hide.

In case he does not believe you, you might want to reconsider simply killing the assassinator as suggested in step two.

Step eight:

Escort Hitler to the Eagle’s Nest and make sure no one knows about it. This is necessary because later there will be no historic records about his whereabouts at that time.

Step eight:

Put a mega-doses of methamphetamine in Hitler’s orange juice and travel back to your own time. Hitler will go insane because of the mega-doses of methamphetamine and he will make decisions that will later cause his fall.

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