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  1. #1
    Rich's Avatar
    Rich Guest

    Default Will this thing match (or exceed) Hubble?



    We all know the original Hubble (thanks to incompetence at Hughes) had
    a flawed primary. But that was fixed. However, Hubble's pointing
    accuracy is staggering. It will be very lucky if when launched this
    scope can achieve the same kind of accuracy. If it can't, despite
    it's aperture, it could end up not operating at a much higher level
    than the current telescope.

    Top german technology for Hubble's successor

    [PIC=:left]Carl Zeiss Optronics, in Oberkochen, Germany, and the Max
    Planck Institute for Astronomy in Heidelberg (MPIA), are developing
    the main fine mechanical optical technology for two instruments to be
    part of the James Webb Space Telescope (JWST).

    Image: The "James Webb Space Telescope" is a European-American
    project. Its capacities will go way beyond those of its predecessor,
    the legendary Hubble Space Telescope. (NASA)

    Over the next eight years, under administration of the European Space
    Agency and NASA in the USA, the JWST (with a mirror of 6.5 metres)
    will shape up to be the successor to the legendary HUBBLE Space
    Telescope. Carl Zeiss and the Max Planck Institute signed a contract
    on November 29 to co-operate in their work on the MIRI and NIRSpec
    instrumentation of the JWST.

    The JAMES WEBB Space Telescope is going to replace the Hubble Space
    Telescope in the next few decades as the most important tool for
    astronomical observation. The most important scientific goal of the
    mission is to discover the "first light" of the early universe - the
    formation of the first stars out of the slowly cooling Big Bang. The
    light from these first stars and galaxies has shifted into the
    infrared spectrum because its wavelength has stretched out some twenty
    times, as the universe has been expanding. The infrared (warm)
    radiation of the telescope and its instruments could disturb these
    weak cosmic signals. In order to prevent this, the telescope has to be
    essentially deep frozen.

    For this reason, the JWST will be stationed at the "Lagrangian point
    L2", 1.5 million kilometres outside the Earth's orbit. The
    gravitational forces of the Sun and the Earth balance each other at
    L2, so the JWST can maintain a position synchronous with the sun and
    the Earth, permanently on the far side of the Earth from the sun.
    Here, the telescope and its instruments will cool down to -230 degrees
    Celsius. The extremely high sensitivity and resolution of the huge
    telescope will lead to entirely new insights about the formation of
    stars and planets in the Milky Way Galaxy. These investigations are
    only possible in the infrared spectrum. Unlike visible light, infrared
    light can pass through the thick gas and dust clouds, in which planets
    and stars form, without being appreciably weakened.

    The telescope and its instruments make immense demands. They will be
    subject to initial stress at an acceleration much higher than the
    Earth's, and then cooled down to a temperature almost reaching
    absolute zero (-273 degrees Celsius). After the telescope is put into
    operation at its final location, its astronomical instruments will be
    adjusted to a high level of accuracy and have to be kept there -
    roughly equivalent to targeting the point of a needle from a
    one-kilometre distance.

    The Space Telescope has three instruments on board for data recording:
    MIRI, NIRSpec, and NIRCam. MIRI and NIRSpec are being developed and
    built in Europe. Carl Zeiss and the MPIA will be making a major
    contribution, as the only European representatives, to both
    instruments.

    For the MIRI and NIRSpec, Carl Zeiss will deliver the filter and
    grating changing mechanisms which allow the instruments to be
    precisely configured for various types of observation. The MPIA will
    also be participating in their development and testing. Futhermore,
    Carl Zeiss will be delivering two filter and grating mechanisms for
    the NIRSpec instrument to EADS Astrium. The contract that Carl Zeiss
    and the MPIA signed specifies that they will co-operate in producing
    both instruments.

    The MIRI and NIRSpec mechanisms are similar, related projects. Their
    development and testing will take place in the next two-and-a-half
    years; after that, Carl Zeiss and the MIPA will install them. It is
    planned that in the year 2013, a European Ariane 5 rocket will bring
    the JWST to the Lagrangian point L2. The entire operation with MIRI
    and NIRSpec is being organised by the European Space Agency, the
    German Aerospace Center, and the Max Planck Society.

    Carl Zeiss and the Max Planck Institute for Astronomy have already
    worked together successfully on challenging projects developing space
    instruments. One example is ISOPHOT, a major contribution to the
    success of the European Infrared Space Observatory, ISO. Recently,
    they began co-operating on the PACS instrument of the HERSCHEL
    European space observatory, set to start operations in 2008.

    Carl Zeiss and the MPIA have won a great deal of trust from
    international partners through their co-operation. Now, the two
    organisations are setting foot on terra nova: astronomers from
    Heidelberg hope to observe the borders of the cosmic "dark ages",
    before stars started to form. Together, they are looking forward to
    developing optomechanical systems of unprecedented quality. They will
    guarantee both success for the astronomical "flagship" mission JWST,
    and a competitive edge for all kinds of imaginable future
    applications.

    Source: Max-Planck-Gesellschaft




    This news is brought to you by PhysOrg.com


  2. #2
    Phil Wheeler's Avatar
    Phil Wheeler Guest

    Default Will this thing match (or exceed) Hubble?

    Rich wrote:


    JWST should outperform Hubble. But it is a tough design challenge (I've
    done a bit of consulting on it).

    One thing is certain: No one is likely to go fix it after it gets on
    station

    Phil

  3. #3
    Tim Killian's Avatar
    Tim Killian Guest

    Default Will this thing match (or exceed) Hubble?

    Rich wrote:

    HST was designed 25 years ago. Considering the billions of dollars spent
    to keep its flawed, aging carcass working, IMO it was not a good
    investment for American taxpayers. We need many different scopes on
    orbit for redundancy and to allow for the introduction of new
    technology. I hope ESA will not put all its eggs in one basket - a
    lesson NASA never really learned.


  4. #4
    George's Avatar
    George Guest

    Default Will this thing match (or exceed) Hubble?


    "Tim Killian" <TJK@notmyrealemail.com> wrote in message
    news:8dGdnVoRiOIp6wvenZ2dnUVZ_sidnZ2d@bresnan.com. ..

    Your opinion is noted. My opinion is that no other satellite put into
    orbit has made more discoveries nor advanced astronomy and astrophysics
    like Hubble has. Not a good investment? It paid for itself with all the
    discoveries it has made, many of which would not have been possible with
    any other craft or technology currently available on the ground or in the
    air. If I'm wrong in this opinion, then I'm wrong. I think that the huge
    outcry of people wanting Hubble to be saved demonstrates clearly that I'm
    not wrong.



  5. #5
    Chris.B's Avatar
    Chris.B Guest

    Default Will this thing match (or exceed) Hubble?

    One tends to forget the constantly improving technology surrounding
    such projects. Just as there are elderly ground-based instruments now
    using new technology the orbiting telescopes no doubt gain from the
    steady improvements in software, computer, optical and sensor
    technology.

    It would be a mistake to place the telescope where the odd visit
    couldn't easily and safely add new generations of technology. Perhaps
    such visits will drive to improve our space travel techniques? Or
    remote repairs, computer and sensor replacements could be achieved via
    robots much like remote surgery? But only if the telesope is designed
    for such updating.

    If it follows typical modern road vehicle technology it will become
    just more orbiting space debris the moment it needs a new headlamp
    bulb. Probably requiring the removal of the primary just to get at the
    one-off fasteners that only an emaciated child can reach . :-)


  6. #6
    Davoud's Avatar
    Davoud Guest

    Default Will this thing match (or exceed) Hubble?

    Chris.B:


    The JWST is not designed for such updating; it has been designed from
    day 1 to reside in an L2 Lissajous orbit, about 1.5 million km from the
    Earth. See <http://www.jwst.nasa.gov/project/text/orbits.html> for a
    good layman's explanation. One of the more compelling reasons for
    putting the JWST at L2 is stated thusly: "The use of a libration point
    orbit on the anti-sun side of Earth affords continuous viewing, easy
    (direct) access and stable thermal conditions." "Easy (direct) access"
    does not mean service access; rather, it means access of the launch
    vehicle to L2.


    That isn't the burning issue just now. This is:
    <http://www.jwst.nasa.gov/tradestatus.html>.

    Davoud

    --
    usenet *at* davidillig dawt com

  7. #7
    Phil Wheeler's Avatar
    Phil Wheeler Guest

    Default Will this thing match (or exceed) Hubble?

    Tim Killian wrote:

    There have been worse investments, and some better. But Hubble has been
    one of the best, in terms of science and knowledge return, that we have
    made. It was initially flawed, but other programs have been more
    fatally flawed. In the end the flaws were overcome and the returns have
    been unparalleled.

    Re "eggs in one basket" comment: Hubble has been highly publicized, and
    rightly so given its productive life. But it is far from the only "egg"
    put up there. Among the more notable are Chandra (x-rays) and Compton
    GRO (gamma rays) .. and the list would be into the 20s or so if we went
    back three decades.

    Phil

  8. #8
    g626700-groups@yahoo.com's Avatar
    g626700-groups@yahoo.com Guest

    Default Will this thing match (or exceed) Hubble?

    Good point Davoud, the issue isn't it's capabilities. It will greatly
    surpass Hubble. The issue is whether it gets built as presently
    designed.

    Webb's funding has been diverted to the Moon/Mars missions.

    Greg


  9. #9
    George's Avatar
    George Guest

    Default Will this thing match (or exceed) Hubble?


    "Phil Wheeler" <w6tuh-ng7@yahoo.com> wrote in message
    news:IoBlf.429$ka.333@tornado.socal.rr.com...

    Don't forget Spitzer.

    http://www.spitzer.caltech.edu/

    George



  10. #10
    Phil Wheeler's Avatar
    Phil Wheeler Guest

    Default Will this thing match (or exceed) Hubble?

    Davoud wrote:

    Several odd things in that web page. The oddest is that it appears to
    read the same as when I first saw it in June or so .. and much has
    happened since then.

 

 
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