Sharper than Hubble: Large Binocular Telescope achieves major breakthrough

On 12/20/11 12:56 PM, Sam Wormley wrote:
On 12/19/11 3:37 PM, Brad Guth wrote:
Obviously you and others of your FUD-master kind can't think of one
darn thing that our Earth-moon L1 is good for.


Lagrange Points
http://scienceworld.wolfram.com/phys...ngePoints.html


Better
http://en.wikipedia.org/wiki/Lagrangian_point

On 12/19/11 3:37 PM, Brad Guth wrote:


Obviously you and others of your FUD-master kind can't think of one
darn thing that our Earth-moon L1 is good for.



Lagrange Points
http://www.wolframalpha.com/input/?i=Lagrange+Points+

On Dec 20, 11:04*am, Sam Wormley wrote:
On 12/19/11 3:37 PM, Brad Guth wrote:



Obviously you and others of your FUD-master kind can't think of one
darn thing that our Earth-moon L1 is good for.

* *Lagrange Points
* * *http://www.wolframalpha.com/input/?i=Lagrange+Points+

?

On Dec 20, 11:01*am, Sam Wormley wrote:
On 12/20/11 12:56 PM, Sam Wormley wrote:

On 12/19/11 3:37 PM, Brad Guth wrote:
Obviously you and others of your FUD-master kind can't think of one
darn thing that our Earth-moon L1 is good for.

Lagrange Points
http://scienceworld.wolfram.com/phys...ngePoints.html

* *Better
* * *http://en.wikipedia.org/wiki/Lagrangian_point

?

On Dec 20, 10:56*am, Sam Wormley wrote:
On 12/19/11 3:37 PM, Brad Guth wrote:

Obviously you and others of your FUD-master kind can't think of one
darn thing that our Earth-moon L1 is good for.

* *Lagrange Points
* * *http://scienceworld.wolfram.com/phys...ngePoints.html

?

In article ,
"Mike Dworetsky" writes:
The new best place for observing is at the Earth-Sun Lagrangian point L2,
especially for Infrared observatories.

This is really a minor quibble, but is it clear that L2 is better
than solar orbit (used for Spitzer and Kepler)? I haven't seen the
orbit tradeoff study for JWST (which is going to L2). My main worry
is that L2 requires use of hydrazine for station keeping, and that
can contaminate optical surfaces. L2 has a communication advantage,
but using a big high-gain antenna and/or more powerful transmitter
should give adequate data rate from solar orbit.

As for Earth-Moon L1, see my .sig.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

This is really a minor quibble, but is it clear that L2 is better
than solar orbit (used for Spitzer and Kepler)? I haven't seen the
orbit tradeoff study for JWST (which is going to L2).

An observatory at L2 will have a relatively constant distance for its
lifetime, while an observatory in a trailing solar orbit will have its
distance gradually increasing, meaning a loss of bandwidth in later
years.

Steve Willner wrote:
In article ,
"Mike Dworetsky" writes:
The new best place for observing is at the Earth-Sun Lagrangian
point L2, especially for Infrared observatories.

This is really a minor quibble, but is it clear that L2 is better
than solar orbit (used for Spitzer and Kepler)? I haven't seen the
orbit tradeoff study for JWST (which is going to L2). My main worry
is that L2 requires use of hydrazine for station keeping, and that
can contaminate optical surfaces. L2 has a communication advantage,
but using a big high-gain antenna and/or more powerful transmitter
should give adequate data rate from solar orbit.

Yes, but it reduces the amount of mass budget available for telescope and
detector equipment if the antenna has to be larger. Also, you can save a
small amount of delta-V by not having to go into orbit around the sun.

I wonder if there is a technical spec somewhere that explains why L2 vs
solar orbit.


As for Earth-Moon L1, see my .sig.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Steve Willner wrote:
In article ,
"Mike Dworetsky" writes:
The new best place for observing is at the Earth-Sun Lagrangian
point L2, especially for Infrared observatories.

This is really a minor quibble, but is it clear that L2 is better
than solar orbit (used for Spitzer and Kepler)? I haven't seen the
orbit tradeoff study for JWST (which is going to L2). My main worry
is that L2 requires use of hydrazine for station keeping, and that
can contaminate optical surfaces. L2 has a communication advantage,
but using a big high-gain antenna and/or more powerful transmitter
should give adequate data rate from solar orbit.

Ah. Got it. The real-time control exchange of signals at L2 from ground to
spacecraft would be about 7-8 sec rather than a few minutes. My guess is
that this is the reason L2 is preferred.


As for Earth-Moon L1, see my .sig.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On Dec 21, 12:23*pm, (Steve Willner) wrote:
In article ,
*"Mike Dworetsky" writes:

The new best place for observing is at the Earth-Sun Lagrangian point L2,
especially for Infrared observatories.

This is really a minor quibble, but is it clear that L2 is better
than solar orbit (used for Spitzer and Kepler)? *I haven't seen the
orbit tradeoff study for JWST (which is going to L2). *My main worry
is that L2 requires use of hydrazine for station keeping, and that
can contaminate optical surfaces. *L2 has a communication advantage,
but using a big high-gain antenna and/or more powerful transmitter
should give adequate data rate from solar orbit.

As for Earth-Moon L1, see my .sig.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner * * * * * *Phone 617-495-7123 * *
Cambridge, MA 02138 USA

Right, a 256 thousand tonne do-everything science platform and lunar
space elevator at the Earth-moon L1 is entirely worthless.

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