Lighting Up The Universe with the James Webb Space Telescope
We've all seen images from the Hubble Space Telescope. The billowing galaxies and distant stars that Hubble relays back to Earth have a special allure for the human imagination. Unfortunately, even Hubble, a remarkable success and invaluable to space research, has its limits. The universe expands much farther than even the Hubble telescope can reach – and to close the distance, the James Webb Space Telescope was developed.
In 1996, a small committee pitched the idea of a new infrared observatory to NASA. The telescope would orbit well beyond Hubble and the Earth's Moon, and with a mirror more than 4 meters in diameter, the new telescope would be able to see farther into space and time than ever before. The idea was approved, and from 1997 to 2013, the James Webb Space Telescope – named in honor of the second administrator of NASA – was gradually pieced together, utilizing research and parts from many different organizations like the European Space Agency, the Canadian Space Agency, and Northrop Grumman Space Technology.
The JWST's mission is to uncover the history of the universe, such as how it grew and how stars and planets developed. There are four distinctive goals that the JWST project will be focused on. The first of these is the determination of the First Galaxies. First Galaxies are those galaxies which likely formed just after the Big Bang. The second goal is to study the assembly of the galaxy, and to hopefully create a complete picture of our universe. Because JWST is equipped with an infrared camera, it will be capable of looking through clouds of dust and can identify the birthplaces of stars and the conditions necessary for star formation. The last goal is to observe nearby planets in hopes of identifying ones which might support life.
The main component of the JWST is a massive 18-segment beryllium mirror. Beryllium can withstand the freezing temperatures of space (-220°C ) while remaining lightweight and flexible. A secondary mirror, stationed just in front of the first, will reflect the images into the Science Instrument Module (ISIM), where the JWST's cameras and equipment are stored. A five-layer sunshield will protect the telescope from light and heat, and an array of solar panels will provide solar power for the observatory. The observatory is designed to be self-operational, and due to the distance of its orbit, any maintenance must be done while the JWST is still on Earth.
Once the JWST is in orbit, it will be 1 million miles away from earth, and will be unreachable by space flight for at least the next ten years. To counter this, scientists have taken precautions to make sure that the JWST is as safe and self-sustaining as possible. All systems on the JWST have been designed and developed to survive minor meteor impacts. The solar panels will provide an endless source of power, and the five solar shields will protect it from solar light and heat. For the first six months of its flight, scientists on Earth will gently guide the JWST into its orbit. After that, the JWST has an expected lifespan of between 5.5 to 10 years.
Importance and What We'll Learn
At the very least, JWST could help us understand the birth of our own universe, which is a question that mankind has puzzled over since the beginning of our history. JWST has the potential to not only advance our understanding of space, and therefore our understanding of how to travel and navigate in space, but also may help locate planets with the potential for life. This could range from identifying planets that might be suitable for human life to locating any existing life in the universe. Even the development of the JWST could have an impact. Many of the electronic sensors designed for the Hubble telescope have found their way into electronics like smartphones and tablets, and the JWST technology has advanced well beyond that. It's very possible that the next wave of technology will feature components developed during the construction of the JWST.
Hubble vs. Webb
The JWST is, by definition, a successor to the Hubble telescope. The Hubble, placed into orbit around Earth in 1990, was designed to observe within the visible light spectrum. By contrast, the JWST, orbiting the second Lagrange (L2) point well away from Earth, will work mainly in the infrared range, enabling it to see farther. The size of the two telescopes is greatly different as well. Whereas the Hubble is no larger than a school bus, the JWST is almost as large as a commercial airplane. The Hubble is still in orbit, though it is no longer undergoing regular maintenance and will continue to orbit until its telescope fails. When the JWST is launched in 2018, it may well work alongside the Hubble for a few more years, sending images of the universe back to Earth for current and future scientists to explore.