THE HUBBLE SPACE TELESCOPE
Telescopes have only been around for about 400 years. Since then, they have evolved quickly and helped astronomers make remarkable discoveries. Ground based telescopes were the first, but we needed a way to observe the cosmos in the vacuum of space, without the light pollution and atmosphere of earth. The Hubble Space Telescope (HST) was the tool that helped propel astronomy to the next level. It has helped us understand the universe in new ways, but Hubble's journey has been difficult and it has required many service missions to remain operational. Without those repairs and replacements, Hubble would not have helped make the discoveries it has, from confirming black holes to helping determine the age of the universe, Hubble has been instrumental to our current understanding of the universe. With this said, is Hubble the most important telescope to have ever been built and used? Yes it is, and Hubble will continue to make progress in the field of astronomy throughout its remaining years. To help understand why it is the most important telescope in history, we must first look at why and how it was developed. Ground based telescopes posed many problems for astronomers. Earth's cloud cover, atmosphere, and light pollution all create obstacles for ground-based telescopes. There are some techniques astronomers can use to compensate for these things, but there are still many problems with ground-based telescopes. The turbulence of the air in the atmosphere distorts distant objects and the light pollution makes it difficult to see faint objects. Also, the inability of some forms of radiation to penetrate the atmosphere makes it so some objects in space cannot reach earth's surface, particularly infrared and ultraviolet. X rays and gamma rays are also distorted when they reach earth’s surface.1 The need for a long-term space-based observatory was evident as early as the 1920's when Herman Oberth, the German pioneer of space flight, put forth the idea.2 A telescope that could capture images from above earth's atmosphere where there was less light and distortion would give us valuable research data which could lead to scientific breakthroughs.1 As Lyman Spitzer, an American astronomer who proposed a large space based telescope in 1946 said, Hubble “would not be to augment our current ideas about the universe we live in, but to discover new questions which nobody can yet imagine.”2 Astronomers wanted a large space telescope to see deeper into the cosmos than ever before. In 1972, the Marshall Space Flight Center, under the direction of NASA, led the project for a large space telescope.2 Hubble was designed to make a large range of observations, from comets and asteroids in our own solar system, to distant galaxies light years away. The vision for Hubble was ambitious and it ran into many budget constraints, which slowed the project down considerably. NASA decided to team up with the European Space Agency (ESA) to help fund and develop the project. The HST is 13.1 meters long and weighs 25,500 pounds.3 At the time of its launch, it contained the most technically advanced instruments ever. The Wide Field Planetary Camera, the Faint Object Camera, the Faint Object Spectrograph, the Fine Guidance Sensors, the Goddard High Resolution Spectrograph, and the High Speed Photometer are the main instruments of the HST. These instruments are responsible for the pictures Hubble produce, keeping the telescope pointed in the right direction, intensifying faint objects, detecting a wide range of frequencies, and determining how light from a source changes with time.3
Hubble was scheduled to launch in 1986, but then, the Space Shuttle Challenger exploded. Everything was suspended, but within a few years everything went back to normal and the launch was scheduled for sometime in 1990. Finally, on April 24 1990, 18 years after it had been approved, the Hubble Space...
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