NASA’s Great Observatories (Hubble, Chandra, Spitzer, Webb, etc.)

Exploration of the universe accelerates innovations on Earth. To grasp the wonder of the cosmos, and understand the infinite variety and splendor, we must collect and analyze radiation emitted by phenomena throughout the entire electromagnetic (EM) spectrum. Towards that end, NASA proposed the concept of great observatories, a series of four space- based observatories designed to conduct astronomical studies over many different wavelengths ( visible, gamma rays, x- rays and infra red). NASA's four great observatory satellites are designed to examine a specific region of the EM using very different technologies. An important aspect of the great observatory program was to overlap the operations phases of the missions to enable astronomers to make contemporaneous observations of the object at different wavelengths. Each observatory was designed to push the state of technology in its intended wavelength region. Since the Earth's atmosphere prevents x-rays, gamma-rays, and far-infrared radiation reaching the ground, space missions were essential for the Compton, Chandra, and Spitzer observatories.

All four telescopes have had substantial impact on astronomy and provided vast knowledge of our universe to astronomers all over the world. The opening up of new wavebands to high resolution, high sensitivity observations by the Compton, Chandra, and Spitzer has revolutionized our understanding of a wide range of astronomical objects, and has led to the detection of thousands of new, interesting objects. Hubble has had much larger public and media impact than other telescopes. The James Webb telescope will provide even greater step forward, providing visible images of even more distant galaxies which can be directly compared with the images of nearby galaxies at visible light wavelengths.

This lecture will provide a brief overview of the four major telescopes namely, Hubble, Compton, Chandra, and Spitzer telescopes. After a brief discussion of the EM spectrum, an overview of the four great observatories will be reviewed from the standpoint of when they were launched, statement on the science objectives, and outline of science instrument on-board will be provided. Lastly, an overview of the James Webb telescope will wrap the discussion on the great observatories program. The lecture will conclude with a video tribute to Atlantis, honoring the Space Shuttle's role in launching the 3 out of 4 great observatories into space and building the greatest orbiting Earth observation platform in space for the benefit of mankind, the International Space Station (ISS).