----- Original Message -----
From: "Robert Seeberger" <[EMAIL PROTECTED]>
To: "Killer Bs Discussion" <[EMAIL PROTECTED]>
Sent: Friday, January 23, 2004 10:18 PM
Subject: Re: Suddenly Everyone Has an Opinion about Space
>
> ----- Original Message -----
> From: "Doug Pensinger" <[EMAIL PROTECTED]>
> To: "Killer Bs Discussion" <[EMAIL PROTECTED]>
> Sent: Friday, January 23, 2004 8:36 PM
> Subject: Re: Suddenly Everyone Has an Opinion about Space
>
>
> > John wrote:
> >
> > > I'm curious what others on the List think about the abandonment
of
> > > Hubble.
> > >
> > > In my mind, it seems like the kind of hard, but necessary
decision
> that
> > > our
> > > space program so desperately needs. As I understand, Hubble's
> life
> > > couldn't be extended forever. Moreover, the survival of
Hubble
> is
> > > inextricably linked to the space shuttle/deathtrap. Since we
> > > absolutely,
> > > positively, have to dump the space shuttle - the loss of Hubble
is
> an
> > > unfortunate side effect.
> > >
> >
> > I'm not sure that the abandonment of the Shuttle means we can't
> maintain
> > HST. Are we going to abandon maneuverable spacecraft altogether
and
> with
> > them the ability to repair and maintain expensive satellites?
> >
> > I would want to look at the cost/benefit before abandoning Hubble
> > including the cost of putting a replacement up there. If
> maintaining HST
> > impacts funding a new generation telescope, I'd be for letting it
> go, but
> > if it means giving up the telescopes capability altogether I'd
> consider
> > the decision incredibly myopic (yuk yuk).
> >
> > We already have other stuff up there but I don't know how it
> compares with
> > Hubble. Ronn?
> >
>
> There is the Webb telescope which is supposed to be Hubbell's
> successor.
> It comes online right after Hubble was originally slated to be
> decommished.
> I have heard it is mostly an infrared telescope, but that it also
does
> some visible light. (I'll have to look that up)
>
I just did:
The James Webb Space Telescope (JWST) is an orbiting infrared
observatory that will take the place of the Hubble Space Telescope at
the end of this decade. It will study the Universe at the important
but previously unobserved epoch of galaxy formation. It will peer
through dust to witness the birth of stars and planetary systems
similar to our own. And using JWST, scientists hope to get a better
understanding of the intriguing dark matter problem. The JWST is also
a key element in NASA's Origins Program.
Proposed Launch Date: August 2011
Proposed Launch Vehicle: Ariane 5
Mission Duration: 5 - 10 years
Total payload mass: Approx 6200 kg, including observatory,
on-orbit consumables and launch vehicle adaptor.
Diameter of primary Mirror: ~6.5 m (21.3 ft)
Clear aperture of primary Mirror: 25 m2
Primary mirror material: beryllium
Mass of primary mirror: about one-third as much as Hubble's
Focal length: TBD
Number of primary mirror segments: 18
Optical resolution: ~0.1 arc-seconds
Wavelength coverage: 0.6 - 28 microns
Size of sun shield: ~22 m x 10 m (72 ft x 33 ft)
Orbit: 1.5 million km from Earth at L2 Point
Operating Temperature: <50 K (-370 �F)
Cost: $824.8 million
Mission Goals
a.. Determine the shape of the Universe.
b.. Explain galaxy evolution
c.. Understand the birth and formation of stars
d.. Determine how planetary systems form and interact.
e.. Determine how the Universe built up its present
chemical/elemental composition.
f.. Probe the nature and abundance of Dark Matter.
JWST Instruments
a.. Near Infrared Camera (NIRCam)
b.. Near Infrared Spectrograph (NIRSpec)
c.. Mid Infrared Instrument (MIRI)
d.. Fine Guidance Sensors (FGS)
Major Innovations
a.. Lightweight optics
b.. Deployable sunshield
c.. Folding segmented mirror
d.. Improved Detectors
e.. Cryogenic actuators & mirror control
f.. Micro-shutters
xponent
Aw Crap, No Visible Light Capability Maru
rob
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