To Good To Be True....Let's save the Hubble

Michael McCulloch wrote:

The Hubble has served it's purpose and has had a good life.

But it could still be useful for less than building something new.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

This is just false. Ground-based observatories have been able to exceed
the resolution of Hubble for many years but that's over a very small
field, but the list of caveats and limitations on the use of AO on
ground-based systems is lengthy. Aside from the obvious limitations of
all ground-based systems that can only be used in good weather and at
night, good seeing is still required for AO systems to operate at their
best. Also, AO works only over a very small area in the center of the
field, while HST takes huge wide-field diffraction-limited images every
time. Ground-based telescopes are limited to wavelengths that get
through the Earth's atmosphere, too. And most AO systems work in
near-IR most of the time largely because the correction is easier to
accomplish there. But the gain with AO is less in longer wavelengths
and only a few systems work regularly in the visible range. The fine
detail achieved by ground-based telescopes does exceed that of Hubble at
times and that's extremely useful but that is no substitute for what
Hubble or any other space telescope can do.

Interferometers working in visible wavelengths are also being built now
(radio and IR have been done for a long time) and the potential for high
resolution from these systems exceeds that of single telescopes by
orders of magnitude. The largest optical interferometer is the CHARA
Array at Mt. Wilson with a maximum baseline (separation between
telescopes) of 350 meters. That gives it the ability to record detail
equivalent to that of a single mirror 350 meters in diameter but also
with a long list of limitations. But that doesn't make them "better"
than Hubble or bigger telescopes with AO systems, either. The
interferometer works along a single line between the telescopes in use
and requires synthetic aperture techniques to build up two-dimensional
information. The light-gathering power is that of the individual
telescopes, 1 meter in the case of CHARA. The world's biggest
telescopes are being combined as optical interferometers with enormous
light-gathering power but with much smaller baselines. The list of
technical difficulties in all of these systems is long. The Space
Interferometer Mission is planned for a very long baseline
interferometer in orbit to reduce some of the problems of being on the
ground (while adding difficulties inherent with being in space).

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

And how many smaller observatories could be built for the price of just
one Keck. Does that make the Kecks and other large telescopes a bad
investment?

But there is more to the story than that Hubble is being abandoned.
I've heard from the proverbial "highly-placed source" that all of the
Origins programs -- including other space telescopes and exploratory
spacecraft -- are jeopardized by the sudden change in plans. The money
has to come from somewhere and the additional billion dollars proposed
over several budget years falls far, far short of what would be needed
for the proposed manned missions. Hubble is just the first -- but
definitely not the last -- casualty (if Hubble is indeed a casualty of
the new budget directives) to come.

Mike Simmons

Michael McCulloch wrote:

The Hubble has served it's purpose and has had a good life.

But it could still be useful for less than building something new.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

This is just false. Ground-based observatories have been able to exceed
the resolution of Hubble for many years but that's over a very small
field, but the list of caveats and limitations on the use of AO on
ground-based systems is lengthy. Aside from the obvious limitations of
all ground-based systems that can only be used in good weather and at
night, good seeing is still required for AO systems to operate at their
best. Also, AO works only over a very small area in the center of the
field, while HST takes huge wide-field diffraction-limited images every
time. Ground-based telescopes are limited to wavelengths that get
through the Earth's atmosphere, too. And most AO systems work in
near-IR most of the time largely because the correction is easier to
accomplish there. But the gain with AO is less in longer wavelengths
and only a few systems work regularly in the visible range. The fine
detail achieved by ground-based telescopes does exceed that of Hubble at
times and that's extremely useful but that is no substitute for what
Hubble or any other space telescope can do.

Interferometers working in visible wavelengths are also being built now
(radio and IR have been done for a long time) and the potential for high
resolution from these systems exceeds that of single telescopes by
orders of magnitude. The largest optical interferometer is the CHARA
Array at Mt. Wilson with a maximum baseline (separation between
telescopes) of 350 meters. That gives it the ability to record detail
equivalent to that of a single mirror 350 meters in diameter but also
with a long list of limitations. But that doesn't make them "better"
than Hubble or bigger telescopes with AO systems, either. The
interferometer works along a single line between the telescopes in use
and requires synthetic aperture techniques to build up two-dimensional
information. The light-gathering power is that of the individual
telescopes, 1 meter in the case of CHARA. The world's biggest
telescopes are being combined as optical interferometers with enormous
light-gathering power but with much smaller baselines. The list of
technical difficulties in all of these systems is long. The Space
Interferometer Mission is planned for a very long baseline
interferometer in orbit to reduce some of the problems of being on the
ground (while adding difficulties inherent with being in space).

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

And how many smaller observatories could be built for the price of just
one Keck. Does that make the Kecks and other large telescopes a bad
investment?

But there is more to the story than that Hubble is being abandoned.
I've heard from the proverbial "highly-placed source" that all of the
Origins programs -- including other space telescopes and exploratory
spacecraft -- are jeopardized by the sudden change in plans. The money
has to come from somewhere and the additional billion dollars proposed
over several budget years falls far, far short of what would be needed
for the proposed manned missions. Hubble is just the first -- but
definitely not the last -- casualty (if Hubble is indeed a casualty of
the new budget directives) to come.

Mike Simmons

Michael McCulloch wrote:

The Hubble has served it's purpose and has had a good life.

But it could still be useful for less than building something new.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

This is just false. Ground-based observatories have been able to exceed
the resolution of Hubble for many years but that's over a very small
field, but the list of caveats and limitations on the use of AO on
ground-based systems is lengthy. Aside from the obvious limitations of
all ground-based systems that can only be used in good weather and at
night, good seeing is still required for AO systems to operate at their
best. Also, AO works only over a very small area in the center of the
field, while HST takes huge wide-field diffraction-limited images every
time. Ground-based telescopes are limited to wavelengths that get
through the Earth's atmosphere, too. And most AO systems work in
near-IR most of the time largely because the correction is easier to
accomplish there. But the gain with AO is less in longer wavelengths
and only a few systems work regularly in the visible range. The fine
detail achieved by ground-based telescopes does exceed that of Hubble at
times and that's extremely useful but that is no substitute for what
Hubble or any other space telescope can do.

Interferometers working in visible wavelengths are also being built now
(radio and IR have been done for a long time) and the potential for high
resolution from these systems exceeds that of single telescopes by
orders of magnitude. The largest optical interferometer is the CHARA
Array at Mt. Wilson with a maximum baseline (separation between
telescopes) of 350 meters. That gives it the ability to record detail
equivalent to that of a single mirror 350 meters in diameter but also
with a long list of limitations. But that doesn't make them "better"
than Hubble or bigger telescopes with AO systems, either. The
interferometer works along a single line between the telescopes in use
and requires synthetic aperture techniques to build up two-dimensional
information. The light-gathering power is that of the individual
telescopes, 1 meter in the case of CHARA. The world's biggest
telescopes are being combined as optical interferometers with enormous
light-gathering power but with much smaller baselines. The list of
technical difficulties in all of these systems is long. The Space
Interferometer Mission is planned for a very long baseline
interferometer in orbit to reduce some of the problems of being on the
ground (while adding difficulties inherent with being in space).

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

And how many smaller observatories could be built for the price of just
one Keck. Does that make the Kecks and other large telescopes a bad
investment?

But there is more to the story than that Hubble is being abandoned.
I've heard from the proverbial "highly-placed source" that all of the
Origins programs -- including other space telescopes and exploratory
spacecraft -- are jeopardized by the sudden change in plans. The money
has to come from somewhere and the additional billion dollars proposed
over several budget years falls far, far short of what would be needed
for the proposed manned missions. Hubble is just the first -- but
definitely not the last -- casualty (if Hubble is indeed a casualty of
the new budget directives) to come.

Mike Simmons

(BllFs6) wrote in message ...
NONE, it cost even MORE to build those massice scopes and the computers and
optics to do what the Hubble does without them.

Nope.....

A shuttle launch cost roughly 500!!! million dollars.... (and NASA may well be
hiding some of the real costs elsewhere in their budget...and then you have to
add how much it cost for training the astronauts....and designing and building
the replacement instruments....

THAT kind of money would buy a handful of LARGE state of the art ground based
observatories....or even hundreds to thousands "small" but never the less
extremely useful telescopes/observatories (contrary to popular opinion size
aint everthing ....

Dont get me wrong...I love astronomy and the space program.....but the shuttle
was just a good try at an idea that just didnt work ever (cheap resuable
spacecraft)....


Don't forget the possible spin-offs that a Mars effort might bring.
We might get a new class of lifter that could launch a Hubble big
brother. Also, I don't get why it has to be the shuttle that services
the Hubble. Couldn't a Soyuz do the same thing?

Steve O

(BllFs6) wrote in message ...
NONE, it cost even MORE to build those massice scopes and the computers and
optics to do what the Hubble does without them.

Nope.....

A shuttle launch cost roughly 500!!! million dollars.... (and NASA may well be
hiding some of the real costs elsewhere in their budget...and then you have to
add how much it cost for training the astronauts....and designing and building
the replacement instruments....

THAT kind of money would buy a handful of LARGE state of the art ground based
observatories....or even hundreds to thousands "small" but never the less
extremely useful telescopes/observatories (contrary to popular opinion size
aint everthing ....

Dont get me wrong...I love astronomy and the space program.....but the shuttle
was just a good try at an idea that just didnt work ever (cheap resuable
spacecraft)....


Don't forget the possible spin-offs that a Mars effort might bring.
We might get a new class of lifter that could launch a Hubble big
brother. Also, I don't get why it has to be the shuttle that services
the Hubble. Couldn't a Soyuz do the same thing?

Steve O

(BllFs6) wrote in message ...
NONE, it cost even MORE to build those massice scopes and the computers and
optics to do what the Hubble does without them.

Nope.....

A shuttle launch cost roughly 500!!! million dollars.... (and NASA may well be
hiding some of the real costs elsewhere in their budget...and then you have to
add how much it cost for training the astronauts....and designing and building
the replacement instruments....

THAT kind of money would buy a handful of LARGE state of the art ground based
observatories....or even hundreds to thousands "small" but never the less
extremely useful telescopes/observatories (contrary to popular opinion size
aint everthing ....

Dont get me wrong...I love astronomy and the space program.....but the shuttle
was just a good try at an idea that just didnt work ever (cheap resuable
spacecraft)....


Don't forget the possible spin-offs that a Mars effort might bring.
We might get a new class of lifter that could launch a Hubble big
brother. Also, I don't get why it has to be the shuttle that services
the Hubble. Couldn't a Soyuz do the same thing?

Steve O

(BllFs6) wrote in message ...
NONE, it cost even MORE to build those massice scopes and the computers and
optics to do what the Hubble does without them.

Nope.....

A shuttle launch cost roughly 500!!! million dollars.... (and NASA may well be
hiding some of the real costs elsewhere in their budget...and then you have to
add how much it cost for training the astronauts....and designing and building
the replacement instruments....

THAT kind of money would buy a handful of LARGE state of the art ground based
observatories....or even hundreds to thousands "small" but never the less
extremely useful telescopes/observatories (contrary to popular opinion size
aint everthing ....

Dont get me wrong...I love astronomy and the space program.....but the shuttle
was just a good try at an idea that just didnt work ever (cheap resuable
spacecraft)....


Don't forget the possible spin-offs that a Mars effort might bring.
We might get a new class of lifter that could launch a Hubble big
brother. Also, I don't get why it has to be the shuttle that services
the Hubble. Couldn't a Soyuz do the same thing?

Steve O

On Sat, 17 Jan 2004 00:33:08 -0500, Michael McCulloch
wrote:

The Hubble has served it's purpose and has had a good life.

It's far from the end of its useful life yet.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

As other people have noted, ground based observatories can't fully
substitute for Hubble.

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

Well, if they cancelled all manned spaceflight for cost reasons, that
would at least have a consistent logic to it. What makes this perverse
lunacy is that they're still spending the money anyway, on busywork
trips to that useless orbital camping trailer. It doesn't even make
sense from a political standpoint; if they can't do routine
maintenance work in low orbit, there's not much chance of people
believing the talk about NASA sending people to Mars.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace

On Sat, 17 Jan 2004 00:33:08 -0500, Michael McCulloch
wrote:

The Hubble has served it's purpose and has had a good life.

It's far from the end of its useful life yet.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

As other people have noted, ground based observatories can't fully
substitute for Hubble.

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

Well, if they cancelled all manned spaceflight for cost reasons, that
would at least have a consistent logic to it. What makes this perverse
lunacy is that they're still spending the money anyway, on busywork
trips to that useless orbital camping trailer. It doesn't even make
sense from a political standpoint; if they can't do routine
maintenance work in low orbit, there's not much chance of people
believing the talk about NASA sending people to Mars.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace

On Sat, 17 Jan 2004 00:33:08 -0500, Michael McCulloch
wrote:

The Hubble has served it's purpose and has had a good life.

It's far from the end of its useful life yet.

The future of telescopes is ground-based interferometry and adaptive
optics. Such observations have already exceeded the capability of the
Hubble in some instances and are much less expensive to deploy and
maintain.

As other people have noted, ground based observatories can't fully
substitute for Hubble.

How many state-of-the-art ground observatories can be built for the
cost of one Hubble servicing mission?

Well, if they cancelled all manned spaceflight for cost reasons, that
would at least have a consistent logic to it. What makes this perverse
lunacy is that they're still spending the money anyway, on busywork
trips to that useless orbital camping trailer. It doesn't even make
sense from a political standpoint; if they can't do routine
maintenance work in low orbit, there's not much chance of people
believing the talk about NASA sending people to Mars.

--
"Sore wa himitsu desu."
To reply by email, remove
the small snack from address.
http://www.esatclear.ie/~rwallace