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Main
Date: 11 May 2007 09:30:35
From: Rich
Subject: James Webb telescope
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1.5M miles. God help them if it needs a service mission.
http://news.bbc.co.uk/2/hi/americas/6645179.stm
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Date: 12 May 2007 14:50:37
From: Rich
Subject: Re: James Webb telescope
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On May 11, 12:52 pm, Sam Wormley <sworml...@mchsi.com > wrote:
> Rich wrote:
> > 1.5M miles. God help them if it needs a service mission.
>
> >http://news.bbc.co.uk/2/hi/americas/6645179.stm
>
> No spacecraft locate in the vicinity of L2 are intended
> to be serviced. The either work or they don't.
Imagine then the original Hubble sitting out there...
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Date: 12 May 2007 12:49:47
From: canopus56
Subject: Re: James Webb telescope
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On May 11, 6:17 pm, Jim Klein <jamesekl...@earthlink.net > wrote:
> At my last day job at Northrop Grumman, I was the lead optical
> designer/analyst for the James Webb Space Telescope (NGST at the time)
> working with on the proposal and later with the Telescope prime, Ball
> Aerospace.
Jim, Thanks for the in-the-know insider view. We are all looking
forward to many years of great images from the Webb, as we have had
from the Hubble. Too bad there isn't enough of a window to re-
engineer the Webb to have exchangeable components that could be
robotically removed and replaced. - Kurt
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Date: 11 May 2007 18:39:14
From: Rich
Subject: Re: James Webb telescope
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On May 11, 8:17 pm, Jim Klein <jamesekl...@earthlink.net > wrote:
> Hi,
>
> At my last day job at Northrop Grumman, I was the lead optical
> designer/analyst for the James Webb Space Telescope (NGST at the time)
> working with on the proposal and later with the Telescope prime, Ball
> Aerospace.
>
> They are acutely aware of the fact that only the Enterprise NCC 1701D
> will be able to service the telescope at its Lagrange point and (trust
> me on this one) everything is being done so as to not repeat the
> HUBBLE PIE eating episode which NASA experienced.
>
> If they blow this, there will be very top level careers on the line at
> a large number of organizations and it will be a joke told for
> hundreds of years.
>
They'll just change their name, like the people who made the Hubble
mirror did, and they likely won't pay for the mistake.
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Date: 12 May 2007 12:03:56
From: Esmail Bonakdarian
Subject: Re: James Webb telescope
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Rich wrote:
> On May 11, 8:17 pm, Jim Klein <jamesekl...@earthlink.net> wrote:
>> Hi,
>> If they blow this, there will be very top level careers on the line at
>> a large number of organizations and it will be a joke told for
>> hundreds of years.
>>
>
> They'll just change their name, like the people who made the Hubble
> mirror did, and they likely won't pay for the mistake.
>
Just like ValuJet became AirTran after the horrible crash in 1997.
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Date: 12 May 2007 00:17:28
From: Jim Klein
Subject: Re: James Webb telescope
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Hi,
At my last day job at Northrop Grumman, I was the lead optical
designer/analyst for the James Webb Space Telescope (NGST at the time)
working with on the proposal and later with the Telescope prime, Ball
Aerospace.
They are acutely aware of the fact that only the Enterprise NCC 1701D
will be able to service the telescope at its Lagrange point and (trust
me on this one) everything is being done so as to not repeat the
HUBBLE PIE eating episode which NASA experienced.
If they blow this, there will be very top level careers on the line at
a large number of organizations and it will be a joke told for
hundreds of years.
Jim Klein
Rich <rander3127@gmail.com > wrote:
>1.5M miles. God help them if it needs a service mission.
>
>http://news.bbc.co.uk/2/hi/americas/6645179.stm
James E. Klein
jameseklein@earthlink.net
Engineering Calculations
http://www.ecalculations.com
ecalculations@ecalculations.com
Engineering Calculations is the home of
the KDP-2 Optical Design Program
for Windows.
1-818-507-5706 (Voice and Fax)
1-818-823-4121
"KDP2, not quite easy enough for a Caveman to use" :-)
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Date: 11 May 2007 12:37:46
From: canopus56
Subject: Re: James Webb telescope
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On May 11, 10:30 am, Rich <rander3...@gmail.com > wrote:
> 1.5M miles. God help them if it needs a service mission.
>
> http://news.bbc.co.uk/2/hi/americas/6645179.stm
Rich, NASA is also working on robotic repair satellites. These would
fly between observing and weather satellites making repairs, replacing
power supplies and upgrade systems. This is a pretty common sense idea
- one that you would have thought would have been pursed earlier in
the space program. - Canopus56
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Date: 12 May 2007 00:57:16
From: Ed
Subject: Re: James Webb telescope
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"canopus56" <canopus56@yahoo.com > wrote:
>
> Rich, NASA is also working on robotic repair satellites. These would
> fly between observing and weather satellites making repairs, replacing
> power supplies and upgrade systems. This is a pretty common sense idea
> - one that you would have thought would have been pursed earlier in
> the space program. - Canopus56
NASA has long desired to have such capability, but the enabling technology
is only recently allowing it to finally happen. Witness ASTRO and NextSat,
doing their servicing thing right now:
http://science.nasa.gov/headlines/y2007/05mar_nohands.htm
http://www.darpa.mil/orbitalexpress/mission_updates.html
http://www.darpa.mil/orbitalexpress/on_orbit_pics.html
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Date: 12 May 2007 00:20:10
From: Jim Klein
Subject: Re: James Webb telescope
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canopus56 <canopus56@yahoo.com > wrote:
>On May 11, 10:30 am, Rich <rander3...@gmail.com> wrote:
>> 1.5M miles. God help them if it needs a service mission.
>>
>> http://news.bbc.co.uk/2/hi/americas/6645179.stm
>
>Rich, NASA is also working on robotic repair satellites. These would
>fly between observing and weather satellites making repairs, replacing
>power supplies and upgrade systems. This is a pretty common sense idea
>- one that you would have thought would have been pursed earlier in
>the space program. - Canopus56
Never underestimate the short sightedness at NASA.
Jim
James E. Klein
jameseklein@earthlink.net
Engineering Calculations
http://www.ecalculations.com
ecalculations@ecalculations.com
Engineering Calculations is the home of
the KDP-2 Optical Design Program
for Windows.
1-818-507-5706 (Voice and Fax)
1-818-823-4121
"KDP2, not quite easy enough for a Caveman to use" :-)
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Date: 11 May 2007 10:29:24
From: oriel36
Subject: Re: James Webb telescope
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Isaac isolated the solar system from the rest of the Universe in
trying to force his terrestrial ballistics agenda into Keplerian
orbital geometry -
"Cor. 2. And since these stars are liable to no sensible parallax from
the annual motion of the earth, they can have no force, because of
their immense distance, to produce any sensible effect in our system.
Not to mention that the fixed stars, every where promiscuously
dispersed in the heavens, by their contrary actions destroy their
mutual actions, by Prop. LXX, Book I."
Newton
As the solar system has a galactic orbital motion,it stands to reason
that the influence of the solar system's gactic orbital motion in one
direction around the Milky Way axis affects heliocentric orbital
geometries as the forward galactic orbital motion of the Sun combined
with the heliocentric orbital motion of the Earth whichj spends 6
months traveling in the direction of galactic orbital motion and 6
months against that galactic orbital motion may,I repeat,may generate
Keplerian orbital geometries.
Of course you lock yourselves in the celestial sphere bubble of Newton
and the exotic offshoots and never get to consider the compound
orbital motions of the Earth.
On May 11, 5:52 pm, Sam Wormley <sworml...@mchsi.com > wrote:
> Rich wrote:
> > 1.5M miles. God help them if it needs a service mission.
>
> >http://news.bbc.co.uk/2/hi/americas/6645179.stm
>
> No spacecraft locate in the vicinity of L2 are intended
> to be serviced. The either work or they don't.
>
> Lagrange Points
> http://scienceworld.wolfram.com/physics/LagrangePoints.html
> http://en.wikipedia.org/wiki/Lagrange_points#Stability
>
> The first three Lagrangian points are technically stable only in
> the plane perpendicular to the line between the two bodies. This
> can be seen most easily by considering the L1 point. A test mass
> displaced perpendicularly from the central line would feel a force
> pulling it back towards the equilibrium point. This is because the
> lateral components of the two masses' gravity would add to produce
> this force, whereas the components along the axis between them
> would balance out. However, if an object located at the L1 point
> drifted closer to one of the masses, the gravitational attraction
> it felt from that mass would be greater, and it would be pulled
> closer. (The pattern is very similar to that of tidal forces.)
>
> Although the L1, L2, and L3 points are nominally unstable, it turns
> out that it is possible to find stable periodic orbits around these
> points, at least in the restricted three-body problem. These
> perfectly periodic orbits, referred to as "halo" orbits, do not
> exist in a full n-body dynamical system such as the solar system.
> However, quasi-periodic (i.e. bounded but not precisely repeating)
> orbits following Lissajous curve trajectories do exist in the
> n-body system. These quasi-periodic Lissajous orbits are what all
> Lagrangian point missions to date have used. Although they are not
> perfectly stable, a relatively modest effort at station keeping can
> allow a spacecraft to stay in a desired Lissajous orbit for an
> extended period of time. It also turns out that, at least in the
> case of Sun-Earth L1 missions, it is actually preferable to
> place the spacecraft in a large amplitude (100,000-200,000 km)
> Lissajous orbit instead of having it sit at the Lagrangian point,
> because this keeps the spacecraft off the direct Sun-Earth
> line and thereby reduces the impacts of solar interference on the
> Earth-spacecraft communications links. Another interesting and
> useful property of the collinear Lagrangian points and their
> associated Lissajous orbits is that they serve as "gateways" to
> control the chaotic trajectories of the Interplanetary Transport
> Network.
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Date: 11 May 2007 12:13:27
From: William C. Keel
Subject: Re: James Webb telescope
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Rich <rander3127@gmail.com > wrote:
> 1.5M miles. God help them if it needs a service mission.
They know that... So did the people who put Chandra, XMM-Newton,
WMAP, and Spitzer way beyond low Earth orbit as well. And IUE
before that - servicing has been a real possibility for only
one telescope, and that was as much political heritage as a purely
engineering decision.
Bill Keel
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Date: 11 May 2007 16:52:09
From: Sam Wormley
Subject: Re: James Webb telescope
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Rich wrote:
> 1.5M miles. God help them if it needs a service mission.
>
> http://news.bbc.co.uk/2/hi/americas/6645179.stm
>
No spacecraft locate in the vicinity of L2 are intended
to be serviced. The either work or they don't.
Lagrange Points
http://scienceworld.wolfram.com/physics/LagrangePoints.html
http://en.wikipedia.org/wiki/Lagrange_points#Stability
The first three Lagrangian points are technically stable only in
the plane perpendicular to the line between the two bodies. This
can be seen most easily by considering the L1 point. A test mass
displaced perpendicularly from the central line would feel a force
pulling it back towards the equilibrium point. This is because the
lateral components of the two masses' gravity would add to produce
this force, whereas the components along the axis between them
would balance out. However, if an object located at the L1 point
drifted closer to one of the masses, the gravitational attraction
it felt from that mass would be greater, and it would be pulled
closer. (The pattern is very similar to that of tidal forces.)
Although the L1, L2, and L3 points are nominally unstable, it turns
out that it is possible to find stable periodic orbits around these
points, at least in the restricted three-body problem. These
perfectly periodic orbits, referred to as "halo" orbits, do not
exist in a full n-body dynamical system such as the solar system.
However, quasi-periodic (i.e. bounded but not precisely repeating)
orbits following Lissajous curve trajectories do exist in the
n-body system. These quasi-periodic Lissajous orbits are what all
Lagrangian point missions to date have used. Although they are not
perfectly stable, a relatively modest effort at station keeping can
allow a spacecraft to stay in a desired Lissajous orbit for an
extended period of time. It also turns out that, at least in the
case of Sun-Earth L1 missions, it is actually preferable to
place the spacecraft in a large amplitude (100,000-200,000 km)
Lissajous orbit instead of having it sit at the Lagrangian point,
because this keeps the spacecraft off the direct Sun-Earth
line and thereby reduces the impacts of solar interference on the
Earth-spacecraft communications links. Another interesting and
useful property of the collinear Lagrangian points and their
associated Lissajous orbits is that they serve as "gateways" to
control the chaotic trajectories of the Interplanetary Transport
Network.
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