The Hubble Space Telescope (HST) has dazzled the world with stunning images of celestial bodies throughout the Universe, and made a myriad of valuable scientific discoveries. Now, after more than 25 years in orbit, NASA officials are sitting at the cusp of launching a new generation of space telescopes to continue and expand on the original mission of the space-borne observatory.
The James Webb Space Telescope (JWST), named after one of NASA's earliest leaders, is the most direct descendant of the HST. This massive orbiting observatory will utilize 18 independent mirrors, carefully aligned to simulate a single giant mirror in space, more than 250 inches in diameter, collecting light from distant bodies. This telescope, significantly larger than the 200-inch instrument at Mount Palomar, is scheduled for launch in October 2018, aboard an Ariane 5 rocket.
The Webb Telescope will be utilized by thousands of astronomers around the globe, searching for a wide variety of data. The observatory will search for exoplanets surrounding other stars, uncover secrets of our own solar system, and stare at objects that formed in the earliest days of the visible universe.
"Hubble's science pushed us to look to longer wavelengths to 'go beyond' what Hubble has already done. In particular, more distant objects are more highly redshifted, and their light is pushed from the UV and optical into the near-infrared. Thus observations of these distant objects (like the first galaxies formed in the Universe, for example) requires an infrared telescope," NASA officials report.
The Wide Field Infrared Survey Telescope (Wfirst) will be capable of viewing 100 times more sky in a single view than is currently possible using the HST. Astronomers believe the instrument will be capable of discovering millions of currently-unknown galaxies, as well as thousands of exoplanets. The observatory, scheduled for launch in the middle of the 2020s, could also measure the effects of dark energy, one of the strangest predictions of theoretical physics. The telescope will be constructed from pieces of an unused spy satellite.
The Transiting Exoplanet Survey Satellite (TESS) mission will lift off in 2017, on a quest to search the entire sky for exoplanets similar to Earth that could be home to alien life. The telescope will record data from alien planets that pass between their sun and our world, resulting in a dip in the amount of light received from the star. This method has been used by ground-based observatories to find larger planets, but the TESS observatory should find smaller worlds, such as super-Earths, orbiting other stars.
Astronomers are also looking further ahead, to the Advanced Technology Large-Aperture Telescope (Atlast), proposed for launch around the year 2030. Still in the earliest stages of planning, the observatory could have a diameter of between 300 and 600 inches. Even the smallest of these proposed designs would result in a telescope 2,000 times more sensitive than Hubble, and capable of five to 10 times greater resolution than the Webb observatory. Astronomers would be able to use that behemoth observatory to search for methane, ozone, water vapor and other telltale signs of life on alien worlds.
In the waning days of Hubble, NASA is ready to dazzle the public, as well as scientists, with a new generation of space-borne observatories.
