![]() Those figures, we can now see, were wildly optimistic.īy 2010, the expected price tag had soared to around $5 billion and the targeted launch had slipped to 2014, even though the observatory had been descoped a bit. Around that time, researchers estimated that the powerful observatory would cost around $1 billion and launch as early as 2007. The basic design of the NGST was pretty much in place by 1996, Smith said. But then-NASA chief Daniel Goldin encouraged the NGST team to think even bigger, and a 26.4-foot-wide (8 m) mirror soon became part of the plan. The original concept called for a primary mirror at least 13.2 feet (4 m) wide. The new observatory would have to be big, too, to collect enough deep-space photons to study. And infrared light travels better than its higher-energy counterparts, more easily penetrating the clouds of dust and gas that pepper the cosmos. After all, the optical and UV emissions from the first stars and galaxies have been stretched so much by the universe's ongoing expansion that we see them now in longer infrared wavelengths. That overarching ambition meant the new scope should be optimized to detect and analyze infrared light, which we feel as heat - a key difference from Hubble, which views mainly in optical and ultraviolet (UV) wavelengths. Related: Building the James Webb Space Telescope (gallery) But the astronomy community wanted to probe even more deeply - ideally, all the way back to the epoch of the very first stars and galaxies, which likely formed within the first few hundred million years of the universe's existence. Hubble had by then provided looks at the cosmos as it was just one billion years after the Big Bang (which occurred 13.8 billion years ago), Gardner said. The fix allowed NGST work to move forward again, Smith said - but more than three years of planning time had been lost, or at least compromised.īy the mid-1990s, a consensus had emerged that the NGST should study the very early universe. Spacewalking astronauts did just that in December 1993, installing corrective optics and replacement instruments that compensated for a flaw in Hubble's 7.9-foot-wide (2.4 meters) primary mirror. "Things really moving very much as a consequence," Smith said during a presentation last week with NASA's Future In-Space Operations working group, referring to the status of the NGST's development at the time. NASA's James Webb Space Telescope is seen during sunshield deployment tests before launch. This unexpected development had a chilling effect on planning for the NGST, said Robert Smith, a history professor at the University of Alberta in Canada who has written extensively about Hubble and other astronomy missions. Hubble launched to Earth orbit successfully in April 1990, but it soon became apparent that something was very wrong: The first images the scope returned were disappointingly blurry. And in this particular case, there was a strong desire to minimize the chance of a long observing gap between Hubble and a "Next Generation Space Telescope" (NGST), as the successor was informally called. Hubble hadn't even launched yet, but big space telescopes take a long time to plan and build, so the astronomy community tends to think a decade or two in advance. The ball first got rolling in September 1989, when a group of astronomers met at the Space Telescope Science Institute in Baltimore to discuss a possible successor to the Hubble Space Telescope. ![]() Webb has been in the works for more than three decades.
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