My entry awhile back on the recent space shuttle mission triggered a comment-section discussion between myself and my friend Robert about, among other things, plans for a new space telescope to replace the aging Hubble. Well, Robert, just for you, I’m linking to this article about that new telescope, which has just reached a big manufacturing milestone related to its primary mirror. Fantabulous factoids about said mirror and the telescope to which it belongs follow:
The [James] Webb [Space] Telescope features a 6.5-meter (20 feet) aperture primary mirror comprised of 18 beryllium segments and will be the largest deployable telescope ever launched. …JWST will peer into the infrared at great distances to search for answers to astronomers’ fundamental questions about the birth and evolution of galaxies, the size and shape of the universe and the mysterious life cycle of matter. The space-based observatory will reside in an orbit 940,000 miles from Earth at the L2 Lagrange point.
The Lagrange points, for the non-geeky among us, are places in space where an object will be stationary relative to both the Earth and the Moon, rather than continuously changing position like ordinary satellites.
This has been another interesting but essentially useless exercise in trivia, courtesy of Simple Tricks and Nonsense. You may now return to your regularly scheduled Web surfing.
Thanks for putting this up, Jason. I think this is really important. And, as you mentioned in our previous exchange, this is exactly the kind of thing that a robust shuttle program enables us to do.
Do you know how the “Langrange point” is measured? “L2” sounds like a coordinate system (like on terrestrial maps), but you would expect such a system to measure three dimensions.
Hi guys,
The Lagrange points are like “geosynchronous” orbit points for 3 bodies (earth, moon, and telescope). The L2 point appears to be just beyond the moon. Check it out on Wikipedia for more info than you would ever want…
Thanks for the tip, Keith. Robert (or anyone else who may be interested), here’s the address for that Wiki entry he was talking about:
http://en.wikipedia.org/wiki/Lagrange_point
Something else I just thought of, in reference to a robust shuttle program: as much as I believe in keeping the space shuttle flying, it won’t be of much use to the Webb telescope. The Lagrange points are well beyond the shuttle’s range. I believe the Webb isn’t supposed to need servicing, but if it did, a manned mission will require some new spacecraft, something more akin to the old Apollos, to actually reach it.
Keith, I am impressed. This is much more complicated than I imagined! Thanks for the info.