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Launch Countdown James Webb Telescope - NASA
- chasil 5y agoThe JWST might very well perish before the Huble. Reviewing the wiki: Infrared telescopes have a disadvantage: the telescope must be kept very cold in order to observe in the infrared without interference... below 50 K. The telescope's sunshield ripped during a practice deployment. JWST will operate... 1,500,000 km beyond Earth's orbit. Hubble orbits [at] 550 km. The Webb telescope will use 126 small motors to occasionally adjust the optics. ...most infrared telescopes have a lifespan limited by their coolant, as short as a few months, maybe a few years at most. [The JWST] is designed to cool itself without a dewar, using a combination of sunshields and radiators, with the mid-infrared instrument using an additional cryocooler. The review also found JWST had 344 potential single-point failures, any of which could doom the project. 2010 Nature article: "The telescope that ate astronomy." Its nominal mission time is five years, with a goal of ten years. JWST needs to use propellant to maintain its halo orbit around L2, which provides an upper limit to its designed lifetime, and it is being designed to carry enough for ten years. Do not expect 30 years of service from this device.
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