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| Yama... |
 Posted: Sat Oct 31, 2009 1:08 am |
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Guest
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Augustine Commission pretty much recommends in its report what it calls
"Flexible Path" - wide array of potential targets to be visited by manned
spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
moons of Mars, Lagrange points etc. It has got blogosphere all excited.
Is there something I'm not getting there? Because quite frankly, that sounds like
biggest idiocy I've heard for long long time. I mean, what there is in Lagrange points
for humans to do? They are just empty space. Manned mission to NEO sounds like one of
big cost for limited return. And why would anyone want a mission where astronauts go through
all the trouble and tedous transit to Mars, only not land there?
Another thing: Augustine Commission supports orbital refueling to get around launch
vehicle limitations. Is this really practical? Because it sure doesn't sound like it would be. |
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| Brian Thorn... |
| Posted: Sat Oct 31, 2009 9:44 am |
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On Sat, 31 Oct 2009 11:08:47 +0000 (UTC), Yama
<tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
[quote]Augustine Commission pretty much recommends in its report what it calls
"Flexible Path" - wide array of potential targets to be visited by manned
spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
moons of Mars, Lagrange points etc. It has got blogosphere all excited.
[/quote]
I call it the "Build the Infrastructure Now, Decide Where To Go Later"
approach. Basically, the AC saw that the current "Back to the Moon, On
To Mars" plan simply doesn't fit the available budget (because NASA
chose or was forced by Congress to choose a hopelessly expensive
infrastructure). Even "Flexible Path" requires a budget increase (just
not as great an increase.) So the AC gave Pres. Obama an option that
keeps exploration on the table without 50% budget increases.
[quote]Is there something I'm not getting there? Because quite frankly, that sounds like
biggest idiocy I've heard for long long time.
[/quote]
You must not be listening to the Public Health Care debate and the
idiocy coming out of both sides of that debate. :-)
[quote]I mean, what there is in Lagrange points
for humans to do?
[/quote]
Service telescopes, in theory. Build a staging area/propellant depot
for lunar or deep space missions.
[quote]They are just empty space. Manned mission to NEO sounds like one of
big cost for limited return. And why would anyone want a mission where astronauts go through
all the trouble and tedous transit to Mars, only not land there?
[/quote]
Remote operation of rovers with only a second or two time delay.
[quote]Another thing: Augustine Commission supports orbital refueling to get around launch
vehicle limitations. Is this really practical?
[/quote]
Progress has been performing orbital refueling for 30 years now, at
the Salyuts, Mir and ISS.
90% or more of any deep space mission is propellant. Propellant is
cheap (compared to hardware). If we can use cheap, modestly reliable
rockets (90% reliablity instead of 99.5%... if we lose one now and
then, who cares? its mostly just LOX) to deliver propellant to a
depot, we should be able to cut the costs of the missions and probably
defer development of the hugely expensive Ares V megarocket. The depot
could potentially grow to become a way station for payloads bound for
geosynchronous orbit, enabling even bigger comsats. The fuel delivery
market could finally foster development of true Reusable Launch
Vehicles, which could radically reduce cost-to-orbit over the long
run.
We should at least try.
Brian |
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| kT... |
| Posted: Sat Oct 31, 2009 11:25 am |
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Yama wrote:
[quote]Augustine Commission pretty much recommends in its report what it calls
"Flexible Path" - wide array of potential targets to be visited by manned
spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
moons of Mars, Lagrange points etc. It has got blogosphere all excited.
Is there something I'm not getting there? Because quite frankly, that sounds like
biggest idiocy I've heard for long long time.
[/quote]
Bigger than Ares I, a technically flawed, fiscally irresponsible launch
vehicle which won't be flying for years duplicating nearly identically
the capabilities of a launch vehicle that has been flying for years now?
[quote]I mean, what there is in Lagrange points
for humans to do? They are just empty space. Manned mission to NEO sounds like one of
big cost for limited return. And why would anyone want a mission where astronauts go through
all the trouble and tedous transit to Mars, only not land there?
[/quote]
You are incapable and incompetent to land on Mars for another several
decades. You just can't recognize your incompetence :
http://www.apa.org/journals/features/psp7761121.pdf
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own
Incompetence Lead to Inflated Self-Assessments
[quote]Another thing: Augustine Commission supports orbital refueling to get around launch
vehicle limitations. Is this really practical? Because it sure doesn't sound like it would be.
[/quote]
Progress and the ISS do it all the time. |
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| Yama... |
| Posted: Sun Nov 01, 2009 2:49 am |
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Guest
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Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
: On Sat, 31 Oct 2009 11:08:47 +0000 (UTC), Yama
: <tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >Augustine Commission pretty much recommends in its report what it calls
: >"Flexible Path" - wide array of potential targets to be visited by manned
: >spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
: >moons of Mars, Lagrange points etc. It has got blogosphere all excited.
: I call it the "Build the Infrastructure Now, Decide Where To Go Later"
: approach. Basically, the AC saw that the current "Back to the Moon, On
: To Mars" plan simply doesn't fit the available budget (because NASA
: chose or was forced by Congress to choose a hopelessly expensive
: infrastructure). Even "Flexible Path" requires a budget increase (just
: not as great an increase.) So the AC gave Pres. Obama an option that
: keeps exploration on the table without 50% budget increases.
I just don't see where the savings are supposed to come. Quite the contrary,
all these proposed targets would need specialized craft and equipment to
design and build. A Phobos mission would be nearly as expensive and difficult for
Mars mission.
It seems to me that they were proposed because they SOUND easier.
Not to mention that science return from asteroid mission is going to be
fraction what can be gained from Moon or Mars mission.
: >I mean, what there is in Lagrange points
: >for humans to do?
: Service telescopes, in theory. Build a staging area/propellant depot
: for lunar or deep space missions.
Except that current and projected Lagrange telescopes are not designed
to be serviceable...
: >They are just empty space. Manned mission to NEO sounds like one of
: >big cost for limited return. And why would anyone want a mission where astronauts go through
: >all the trouble and tedous transit to Mars, only not land there?
: Remote operation of rovers with only a second or two time delay.
I see absolutely no point whatsoever sending people to two-year mission merely
to act as remote rover operators.
: >Another thing: Augustine Commission supports orbital refueling to get around launch
: >vehicle limitations. Is this really practical?
: Progress has been performing orbital refueling for 30 years now, at
: the Salyuts, Mir and ISS.
: 90% or more of any deep space mission is propellant. Propellant is
: cheap (compared to hardware). If we can use cheap, modestly reliable
: rockets (90% reliablity instead of 99.5%... if we lose one now and
: then, who cares? its mostly just LOX)
But doesn't ISS etc use hypergolic fuels, not LOX? |
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| kT... |
| Posted: Sun Nov 01, 2009 9:12 am |
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Yama wrote:
[quote]Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
: On Sat, 31 Oct 2009 11:08:47 +0000 (UTC), Yama
: <tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >Augustine Commission pretty much recommends in its report what it calls
: >"Flexible Path" - wide array of potential targets to be visited by manned
: >spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
: >moons of Mars, Lagrange points etc. It has got blogosphere all excited.
: I call it the "Build the Infrastructure Now, Decide Where To Go Later"
: approach. Basically, the AC saw that the current "Back to the Moon, On
: To Mars" plan simply doesn't fit the available budget (because NASA
: chose or was forced by Congress to choose a hopelessly expensive
: infrastructure). Even "Flexible Path" requires a budget increase (just
: not as great an increase.) So the AC gave Pres. Obama an option that
: keeps exploration on the table without 50% budget increases.
I just don't see where the savings are supposed to come. Quite the contrary,
all these proposed targets would need specialized craft and equipment to
design and build. A Phobos mission would be nearly as expensive and difficult for
Mars mission.
[/quote]
Are you nuts? JAXA could do it.
[quote]It seems to me that they were proposed because they SOUND easier.
[/quote]
They are physically much easier.
[quote]Not to mention that science return from asteroid mission is going to be
fraction what can be gained from Moon or Mars mission.
[/quote]
We have spacecraft on Mars right now.
[quote]
: >I mean, what there is in Lagrange points
: >for humans to do?
: Service telescopes, in theory. Build a staging area/propellant depot
: for lunar or deep space missions.
Except that current and projected Lagrange telescopes are not designed
to be serviceable...
[/quote]
That's the whole point of going there, so we know we can service them.
[quote]: >They are just empty space. Manned mission to NEO sounds like one of
: >big cost for limited return. And why would anyone want a mission where astronauts go through
: >all the trouble and tedous transit to Mars, only not land there?
[/quote]
Because you are demonstrably incompetent and unfunded to do so.
[quote]: Remote operation of rovers with only a second or two time delay.
I see absolutely no point whatsoever sending people to two-year mission merely
to act as remote rover operators.
: >Another thing: Augustine Commission supports orbital refueling to get around launch
: >vehicle limitations. Is this really practical?
: Progress has been performing orbital refueling for 30 years now, at
: the Salyuts, Mir and ISS.
: 90% or more of any deep space mission is propellant. Propellant is
: cheap (compared to hardware). If we can use cheap, modestly reliable
: rockets (90% reliablity instead of 99.5%... if we lose one now and
: then, who cares? its mostly just LOX)
But doesn't ISS etc use hypergolic fuels, not LOX?[/quote] |
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| Brian Thorn... |
| Posted: Mon Nov 02, 2009 6:33 pm |
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Guest
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On Sun, 1 Nov 2009 12:49:46 +0000 (UTC), Yama
<tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
[quote]: >Augustine Commission pretty much recommends in its report what it calls
: >"Flexible Path" - wide array of potential targets to be visited by manned
: >spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
: >moons of Mars, Lagrange points etc. It has got blogosphere all excited.
: I call it the "Build the Infrastructure Now, Decide Where To Go Later"
I just don't see where the savings are supposed to come.
[/quote]
Canceling Altair. Scaling-down Ares V (sized for Moon/Altair) to
existing ET diameter and 4- or 5-segment SRB (vs. 5 1/2 segment now
planned.) Cancel Ares I and move everything to this Ares V-Lite.
Big savings and a more robust launch system.
[quote]Quite the contrary,
all these proposed targets would need specialized craft and equipment to
design and build. A Phobos mission would be nearly as expensive and difficult for
Mars mission.
[/quote]
The simplest asteroid-rendezvous concepts simply call for two Orions
docked end-to-end. You don't really need a lander for a small
asteroid, its really just proximity operations due to the low gravity
(think NEAR's "landing".)
[quote]It seems to me that they were proposed because they SOUND easier.
[/quote]
And they defer the high-cost mission modules (landers, labs,
what-have-you) until later.
[quote]Not to mention that science return from asteroid mission is going to be
fraction what can be gained from Moon or Mars mission.
[/quote]
But potentially much more important if one is discovered on an impact
trajectory.
[quote]Except that current and projected Lagrange telescopes are not designed
to be serviceable...
[/quote]
Chicken meet Egg. There are no servicable observatories at the
Lagrange points because there are no spacecraft that can go out to
service them, and there are no spacecraft that can go out to service
them because there are no observatories that can be serviced.
Servicing something like WISE or SOHO doesn't make much sense, but
when we start talking about something like James Webb at
multiple-billion dollars, adding astronaut servicing starts to look at
least worth considering.
[quote]: >They are just empty space. Manned mission to NEO sounds like one of
: >big cost for limited return. And why would anyone want a mission where astronauts go through
: >all the trouble and tedous transit to Mars, only not land there?
: Remote operation of rovers with only a second or two time delay.
I see absolutely no point whatsoever sending people to two-year mission merely
to act as remote rover operators.
[/quote]
Others do. And this could be tied-in with a Phobos or Deimos "lander".
[quote]: 90% or more of any deep space mission is propellant. Propellant is
: cheap (compared to hardware). If we can use cheap, modestly reliable
: rockets (90% reliablity instead of 99.5%... if we lose one now and
: then, who cares? its mostly just LOX)
But doesn't ISS etc use hypergolic fuels, not LOX?
[/quote]
Same concept. That's why we need to test it first. Two Centaurs or
ACES upper stages transferring propellant back and forth should to the
trick.
Brian |
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| Jorge R. Frank... |
| Posted: Mon Nov 02, 2009 6:55 pm |
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Guest
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Brian Thorn wrote:
[quote]On Sun, 1 Nov 2009 12:49:46 +0000 (UTC), Yama
tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >Augustine Commission pretty much recommends in its report what it calls
: >"Flexible Path" - wide array of potential targets to be visited by manned
: >spacecraft as a precursor to manned Mars mission. These include Near Earth Asteroids,
: >moons of Mars, Lagrange points etc. It has got blogosphere all excited.
: I call it the "Build the Infrastructure Now, Decide Where To Go Later"
I just don't see where the savings are supposed to come.
Canceling Altair. Scaling-down Ares V (sized for Moon/Altair) to
existing ET diameter and 4- or 5-segment SRB (vs. 5 1/2 segment now
planned.) Cancel Ares I and move everything to this Ares V-Lite.
Big savings and a more robust launch system.
Quite the contrary,
all these proposed targets would need specialized craft and equipment to
design and build. A Phobos mission would be nearly as expensive and difficult for
Mars mission.
The simplest asteroid-rendezvous concepts simply call for two Orions
docked end-to-end. You don't really need a lander for a small
asteroid, its really just proximity operations due to the low gravity
(think NEAR's "landing".)
It seems to me that they were proposed because they SOUND easier.
And they defer the high-cost mission modules (landers, labs,
what-have-you) until later.
Not to mention that science return from asteroid mission is going to be
fraction what can be gained from Moon or Mars mission.
But potentially much more important if one is discovered on an impact
trajectory.
Except that current and projected Lagrange telescopes are not designed
to be serviceable...
Chicken meet Egg. There are no servicable observatories at the
Lagrange points because there are no spacecraft that can go out to
service them, and there are no spacecraft that can go out to service
them because there are no observatories that can be serviced.
Servicing something like WISE or SOHO doesn't make much sense, but
when we start talking about something like James Webb at
multiple-billion dollars, adding astronaut servicing starts to look at
least worth considering.
[/quote]
It's worth considering for future space telescopes of comparable cost to
JWST. It doesn't make sense for JWST itself because the design and fab
are too far along to retrofit it for human servicing.
JWST will carry a passive LIDS adapter "just in case" but the systems
are not designed for human servicing; a lot of improvisation would be
required. |
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| Yama... |
| Posted: Wed Nov 04, 2009 1:39 am |
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Guest
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Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
: On Sun, 1 Nov 2009 12:49:46 +0000 (UTC), Yama
: <tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >I just don't see where the savings are supposed to come.
: Canceling Altair. Scaling-down Ares V (sized for Moon/Altair) to
: existing ET diameter and 4- or 5-segment SRB (vs. 5 1/2 segment now
: planned.) Cancel Ares I and move everything to this Ares V-Lite.
: Big savings and a more robust launch system.
Except you'd have to man-rate Ares V Lite, and still design all the
equipment you need for interplanetary travel. Only except that because
of launcher limitations, it is harder.
: >Quite the contrary,
: >all these proposed targets would need specialized craft and equipment to
: >design and build. A Phobos mission would be nearly as expensive and difficult for
: >Mars mission.
: The simplest asteroid-rendezvous concepts simply call for two Orions
: docked end-to-end. You don't really need a lander for a small
: asteroid, its really just proximity operations due to the low gravity
: (think NEAR's "landing".)
Even if this were practical (which I doubt), you'd still have to come up
with the larger craft for Mars mission, even if it's just Phobos or Mars Flyby.
: >It seems to me that they were proposed because they SOUND easier.
: And they defer the high-cost mission modules (landers, labs,
: what-have-you) until later.
Given that the "high-cost mission modules" are the ones which make the whole
program meaningful in the first place, I again foresee no actual savings.
They will have to be developed at some point in any case.
: >Not to mention that science return from asteroid mission is going to be
: >fraction what can be gained from Moon or Mars mission.
: But potentially much more important if one is discovered on an impact
: trajectory.
So what's stopping sending a robotic mission to study one?
: Chicken meet Egg. There are no servicable observatories at the
: Lagrange points because there are no spacecraft that can go out to
: service them, and there are no spacecraft that can go out to service
: them because there are no observatories that can be serviced.
: Servicing something like WISE or SOHO doesn't make much sense, but
: when we start talking about something like James Webb at
: multiple-billion dollars, adding astronaut servicing starts to look at
: least worth considering.
Given the high costs involved, seems dubious. They could have built another
space telescope at the cost of HST service missions.
: >: Remote operation of rovers with only a second or two time delay.
: >
: >I see absolutely no point whatsoever sending people to two-year mission merely
: >to act as remote rover operators.
: Others do.
Who are these "others"? What is the precise value?
: >: 90% or more of any deep space mission is propellant. Propellant is
: >: cheap (compared to hardware). If we can use cheap, modestly reliable
: >: rockets (90% reliablity instead of 99.5%... if we lose one now and
: >: then, who cares? its mostly just LOX)
: >
: >But doesn't ISS etc use hypergolic fuels, not LOX?
: Same concept.
No, not really. It is much more complicated with cryogenics, which is why it hasn't
been done yet.
And really, again, the supposed "savings" seem to evaporate: now you have to
develope technology to store and transfer cryogenic fuels in the orbit,
and to test it with specialized missions. |
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| Brian Thorn... |
| Posted: Wed Nov 04, 2009 8:44 pm |
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Guest
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On Wed, 4 Nov 2009 11:39:07 +0000 (UTC), Yama
<tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
[quote]: Big savings and a more robust launch system.
Except you'd have to man-rate Ares V Lite, and still design all the
equipment you need for interplanetary travel. Only except that because
of launcher limitations, it is harder.
[/quote]
Man-rating is whatever NASA declares it to be, and they've already
recently lowered the requirements for EELV. Stick to as much
Shuttle-heritage hardware as possible (SSME, 4-segment SRB, ET
tankage) and you've gone a long, long way toward man-rating. And NASA
already wants Ares V to be "man-ratable", so we're probably going to
pay for it anyway, Ares I or not. So dump Ares I.
Two Ares V-Lites offer *more* payload than an Ares V and an Ares I,
and because both launchers are identical both pads can be the same,
simplifying ground handling and launch preparations. Dumping Ares I
for Ares V-Lite improves the situation, rather than limiting it.
[quote]Even if this were practical (which I doubt), you'd still have to come up
with the larger craft for Mars mission, even if it's just Phobos or Mars Flyby.
[/quote]
The craft, but not the lander/launcher. Getting down to the Mars
surface and launching again are going to be the monster costs of a
Mars mission. Flexible path does things incrementally, instead of
paying for everything in one fell swoop, which is the case if
President Obama announces "we're going to Mars by 2025!"
[quote]Given the high costs involved, seems dubious. They could have built another
space telescope at the cost of HST service missions.
[/quote]
Perhaps they could have, but probably wouldn't have. There was no
Einstein 2, no IRAS 2, no OAO-2. No NEAR-Shoemaker 2, no Magellan 2,
no Mars Global Surveyor 2. Instead, we got completely new successors
to them all. Internal and external politics generally forces NASA to
order a new 'bigger and better" satellite, which is much easier to
explain to Congress why you need it (versus "Another Hubble? Didn't we
just pay for that?") And that bigger and better means an all-new
design, which is invariably expensive. The only "bigger and better
than Hubble" we have seen so far is James Webb Space Telescope, now
approaching $4.5 billion. Shuttle missions range from $400 million
each for the early Hubble servicing missions to $900 million for the
last two or so. We updated Hubble with state-of-the-art instruments
about four times for less than the cost of JWST.
[quote]: >I see absolutely no point whatsoever sending people to two-year mission merely
: >to act as remote rover operators.
: Others do.
Who are these "others"?
[/quote]
The Augustine Commission, for one.
[quote]What is the precise value?
[/quote]
Operation of rovers in areas that have limited contact with Earth,
such as Valles Marineris.
[quote]: >But doesn't ISS etc use hypergolic fuels, not LOX?
: Same concept.
No, not really. It is much more complicated with cryogenics, which is why it hasn't
been done yet.
[/quote]
Its more complicated, but potentially hugely rewarding. And it has
been tested to a degree, with NASA's SHOOT (Superfluid Helium On-Orbit
Transfer) aboard Shuttle mission STS-57. Small scale, but no
showstoppers.
ULA, which has tons of experience with cryogenic stages, doesn't seem
to think it will be that big a problem. They've already outlined one
concept, which uses a big folding sunshade to keep the cryo stage cool
during loitering/prop transfer.
And really. We're going to have to learn how to do that eventually.
We'll never explore the solar system if we have to take all the fuel
for the mission with us at one time from the launch pad.
[quote]And really, again, the supposed "savings" seem to evaporate: now you have to
develope technology to store and transfer cryogenic fuels in the orbit,
and to test it with specialized missions.
[/quote]
A couple of development missions (which could be used to launch
satellites or cargo to the Space Station as their primary objective)
eats up all the savings of full-scale development and, say ten years
of Ares V launches? I don't think so. And we just happen to have a
Space Station up there just waiting to take on an experiment like
that.
Brian |
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| Yama... |
| Posted: Thu Nov 05, 2009 2:21 am |
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Guest
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Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
: On Wed, 4 Nov 2009 11:39:07 +0000 (UTC), Yama
: <tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >: Big savings and a more robust launch system.
: >
: >Except you'd have to man-rate Ares V Lite, and still design all the
: >equipment you need for interplanetary travel. Only except that because
: >of launcher limitations, it is harder.
: Man-rating is whatever NASA declares it to be, and they've already
: recently lowered the requirements for EELV. Stick to as much
: Shuttle-heritage hardware as possible (SSME, 4-segment SRB, ET
: tankage) and you've gone a long, long way toward man-rating. And NASA
: already wants Ares V to be "man-ratable", so we're probably going to
: pay for it anyway, Ares I or not. So dump Ares I.
: Two Ares V-Lites offer *more* payload than an Ares V and an Ares I,
: and because both launchers are identical both pads can be the same,
: simplifying ground handling and launch preparations. Dumping Ares I
: for Ares V-Lite improves the situation, rather than limiting it.
It will also mean smaller and individually less capable mission modules,
and less capability for direct cargo missions. Here's what Mike Griffin
has to say about Ares V Lite:
"The recommendation in favor of the dual-launch "Ares-5 Lite" approach as the baseline
for lunar missions is difficult to understand. It violates the CAIB recommendation
(and many similar recommendations) to separate crew and cargo in whatever post-Shuttle
human space transportation system is to be developed. Further, the dual-Ares-5 Lite mission architecture
substantially increases the minimum cost for a single lunar mission as compared to the
Ares-1/Ares-5 approach, a recommendation which is difficult to understand in an already difficult
budgetary environment. Finally, the Ares-5 Lite is nearly as expensive to develop as the Ares-5,
but offers significantly less payload to the moon when used -- as will be required -- in a one-way,
single-launch, cargo-only mode. (The LEO payload difference of 140 mt for Ares-5 Lite and 160 mt for
Ares-5 masks a much greater difference in their lunar payload capability.) All parties agree that a
heavy-lift launcher is needed for any human space program beyond LEO. Because of the economies of
scale inherent to the design of launch vehicles, such a vehicle should be designed to lift as large a
payload as possible within the constraints of the facilities and infrastructure available to build
and transport it. This provides the greatest marginal improvement in capability at the lowest
marginal cost."
Not to mention, are you going to use Ares V Lite to launch crews to the
ISS?
: >Even if this were practical (which I doubt), you'd still have to come up
: >with the larger craft for Mars mission, even if it's just Phobos or Mars Flyby.
: The craft, but not the lander/launcher. Getting down to the Mars
: surface and launching again are going to be the monster costs of a
: Mars mission. Flexible path does things incrementally, instead of
: paying for everything in one fell swoop, which is the case if
: President Obama announces "we're going to Mars by 2025!"
Okay, this just makes absolutely no sense. You STILL have to pay for
that lander, eventually. Meanwhile, you are mucking around doing missions
which cost a lot, yet do little to actually advance the cause for manned Mars
mission.
: >Given the high costs involved, seems dubious. They could have built another
: >space telescope at the cost of HST service missions.
: Perhaps they could have, but probably wouldn't have. There was no
: Einstein 2, no IRAS 2, no OAO-2. No NEAR-Shoemaker 2, no Magellan 2,
: no Mars Global Surveyor 2. Instead, we got completely new successors
: to them all. Internal and external politics generally forces NASA to
: order a new 'bigger and better" satellite, which is much easier to
: explain to Congress why you need it (versus "Another Hubble? Didn't we
: just pay for that?") And that bigger and better means an all-new
: design, which is invariably expensive. The only "bigger and better
: than Hubble" we have seen so far is James Webb Space Telescope, now
: approaching $4.5 billion. Shuttle missions range from $400 million
: each for the early Hubble servicing missions to $900 million for the
: last two or so. We updated Hubble with state-of-the-art instruments
: about four times for less than the cost of JWST.
There have been five service missions for HST. Adding the costs up,
when you include designing all the hardware, easily makes up cost
of JWST. Remember, HST was designed under impression that Shuttle flights
are cheap and routine.
: >: Others do.
: >
: >Who are these "others"?
: The Augustine Commission, for one.
What is their rationale for that? (In fact I don't remember such mission
mentioned anywhere in the report. They were vague about what this
Flexible Path is actually going to do).
: >What is the precise value?
: Operation of rovers in areas that have limited contact with Earth,
: such as Valles Marineris.
This makes even less sense. It would combine limitations
of the remote rovers with high cost of manned presence.
It would be much simpler and cheaper to simply launch a Mars communications
satellite (which actually has been planned) to relay commands to rovers from
Earth, if the above is a limitation.
: >And really, again, the supposed "savings" seem to evaporate: now you have to
: >develope technology to store and transfer cryogenic fuels in the orbit,
: >and to test it with specialized missions.
: A couple of development missions (which could be used to launch
: satellites or cargo to the Space Station as their primary objective)
: eats up all the savings of full-scale development and, say ten years
: of Ares V launches? I don't think so. And we just happen to have a
: Space Station up there just waiting to take on an experiment like
: that.
This is pretty goofy logic. Apparently, cost of developing
a 5.5 segment booster from 5-segment booster is too high, but
developing whole new technology, with several dedicated test missions,
not to mention the costs of actually launching refuel missions when and
if the technology actually becomes available, is not. |
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| Brian Thorn... |
| Posted: Thu Nov 05, 2009 10:30 pm |
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Guest
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On Thu, 5 Nov 2009 12:21:03 +0000 (UTC), Yama
<tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
[quote]: Two Ares V-Lites offer *more* payload than an Ares V and an Ares I,
: and because both launchers are identical both pads can be the same,
: simplifying ground handling and launch preparations. Dumping Ares I
: for Ares V-Lite improves the situation, rather than limiting it.
It will also mean smaller and individually less capable mission modules,
[/quote]
It does no such thing. Orion and Altair on one Ares V-Lite, the EDS on
the other.
[quote]and less capability for direct cargo missions.
[/quote]
Not with orbital refueling.
[quote]Here's what Mike Griffin
has to say about Ares V Lite:
[/quote]
Dr. Griffin is totally, hopelessly partial to Ares I / Ares V. He
selected it, with more than a few claiming he stacked the deck against
any other alternative. He's why we're in this mess in the first place.
[quote]"The recommendation in favor of the dual-launch "Ares-5 Lite" approach as the baseline
for lunar missions is difficult to understand. It violates the CAIB recommendation
(and many similar recommendations) to separate crew and cargo in whatever post-Shuttle
human space transportation system is to be developed.
[/quote]
Which was a very bad, very knee-jerk recommendation, poorly justified.
If your Orion has a Launch Escape System, what difference does it make
if cargo is riding on the rocket below the Orion (a'la Apollo Saturn
V)? Orion can eject from a failing Ares V-Lite as easily as it could a
failing Ares I.
[quote]Further, the dual-Ares-5 Lite mission architecture
substantially increases the minimum cost for a single lunar mission as compared to the
Ares-1/Ares-5 approach, a recommendation which is difficult to understand in an already difficult
budgetary environment.
[/quote]
Not so difficult to understand in light of development costs. Ares I +
Ares V require roughly twice the development costs of Ares V-Lite
(which can use existing SSME, existing ET tooling and existing SRBs).
And they require more production facilities (Ares I Upper Stage isn't
needed in Ares V-Lite architecture) plus two brand new and dissimilar
launch pad designs.
[quote]Finally, the Ares-5 Lite is nearly as expensive to develop as the Ares-5,
[/quote]
Not by a long shot. No new SRB design is needed at all, for starters.
No RS-68B development is needed (use SSME, which NASA is reconsidering
anyway). No retooling Michoud for 33-ft diameter tankage is needed. No
new Crawler is needed to haul the vehicle to the pad.
[quote]but offers significantly less payload to the moon when used -- as will be required -- in a one-way,
single-launch, cargo-only mode.
[/quote]
Not with orbital refueling. The cargo-only launch tops off its tanks
at the depot. You actually get greater payload this way.
[quote](The LEO payload difference of 140 mt for Ares-5 Lite and 160 mt for
Ares-5 masks a much greater difference in their lunar payload capability.)
[/quote]
Hence the emphasis on the refueling architecture.
[quote]All parties agree that a
heavy-lift launcher is needed for any human space program beyond LEO. Because of the economies of
scale inherent to the design of launch vehicles,
[/quote]
Economies of scale would be much better served with one launch vehicle
in production, instead of two.
[quote]Not to mention, are you going to use Ares V Lite to launch crews to the
ISS?
[/quote]
Only for the test flights. Operationally, hand that task over to
SpaceX or another commercial provider, who are chomping at the bit for
the job. If they don't pan out, Ares V-Lite / Orion launch costs can
be somewhat mitigated by also carrying an MPLM-equivalent of cargo, or
Ares V-Lite can be launched without its upper stage (Ares V-Very Lite,
I guess!)
[quote]: >Even if this were practical (which I doubt), you'd still have to come up
: >with the larger craft for Mars mission, even if it's just Phobos or Mars Flyby.
: The craft, but not the lander/launcher. Getting down to the Mars
: surface and launching again are going to be the monster costs of a
: Mars mission. Flexible path does things incrementally, instead of
: paying for everything in one fell swoop, which is the case if
: President Obama announces "we're going to Mars by 2025!"
Okay, this just makes absolutely no sense. You STILL have to pay for
that lander, eventually.
[/quote]
I'm not really the biggest fan of the "look but don't touch" Mars
idea, either. But I can see why it is appealing to some. You don't
have to go to Congress next year and ask for $75 billion more. You
"only" have to ask for $50 billion more. Its an easier sell to
Congress and the people, because you prove each step along the way
before getting to the humongous cost and risk... the actual Mars
lander/launcher.
Sure, we'll pay for this eventually either way, but it doesn't lock us
into paying for everything until we know the infrastructure works.
[quote]Meanwhile, you are mucking around doing missions
which cost a lot, yet do little to actually advance the cause for manned Mars
mission.
[/quote]
Except build confidence, reestablish deep space operations, prove
long-duration life support beyond reach of resupply, demonstrate
radiation protection. Retiring a great amount of risk before taking
the final step to the surface of Mars is no small accomplishment.
[quote]There have been five service missions for HST. Adding the costs up,
when you include designing all the hardware, easily makes up cost
of JWST.
[/quote]
No, its very close in costs. But we got more from those five missions
(well, four of them anyway) than just keeping Hubble going. We
replaced instruments with brand new state-of-the-art successors, four
times. They also added instruments in other wavelengths than were
installed originally (NICMOS, for example) and we got more powerful
instruments in visible light and UV that JWST lacks. But JWST still
costs $4.5 billion for just a (very good) IR telescope. In many ways,
we got four new astronomy satellites for about the cost of JWST. Not
too shabby really.
[quote]: A couple of development missions (which could be used to launch
: satellites or cargo to the Space Station as their primary objective)
: eats up all the savings of full-scale development and, say ten years
: of Ares V launches? I don't think so. And we just happen to have a
: Space Station up there just waiting to take on an experiment like
: that.
This is pretty goofy logic. Apparently, cost of developing
a 5.5 segment booster from 5-segment booster
[/quote]
....and RS-68B, and 33-ft tankage, and a new freighter to haul the
stage to KSC, and a new Crawler with a reinforced Crawlerway to handle
the weight, and sacrificing Orion reusability because Ares I can't
handle the weight of the original Orion, and cutting Orion from 6 to 4
crew because Ares I can't handle the original Orion...
Not that 5.5 segment is going to be cheap. Look at 5 segment's high
cost, and how everyone is crying that Ares I-X was nothing because the
four segment SRB is too different than the five segment SRB. The same
will be true of 5.5 segment SRB. A couple of dedicated Centaur flights
would undoubtedly be cheaper than 5.5 segment SRB development.
[quote]is too high, but
developing whole new technology, with several dedicated test missions,
[/quote]
Technology with a potential huge payoff for a great number of
customers, versus just NASA's manned program. We could very possibly
get a commercial partnership (ULA) to cost-share this technology. And
again, not necessarily dedicated test missions: Two Space Station
resupply missions could sacrifice a little payload to the prop
transfer demo hardware. These missions already have rendezvous and
docking capability.
I see it as something like LCROSS's use of a Centaur that was going to
the moon anyway.
[quote]not to mention the costs of actually launching refuel missions when and
if the technology actually becomes available, is not.
[/quote]
Contract out the refueling missions to the lowest bidder. SpaceX would
love the job. There are other low-cost launcher ideas out there that
just need a market case to get the necessary capital investment. Fuel
to LEO would be a substantial market. It might even justify a true
RLV, which would help everybody.
Brian |
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| Greg D. Moore (Strider)... |
| Posted: Thu Nov 05, 2009 11:07 pm |
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Guest
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"Brian Thorn" <bthorn64 at (no spam) suddenlink.net> wrote in message
news:c217f5lurouacsfjv4g6rhfg565p8nkboc at (no spam) 4ax.com...
[quote]
Which was a very bad, very knee-jerk recommendation, poorly justified.
If your Orion has a Launch Escape System, what difference does it make
if cargo is riding on the rocket below the Orion (a'la Apollo Saturn
V)? Orion can eject from a failing Ares V-Lite as easily as it could a
failing Ares I.
[/quote]
If anything a bit easier since the capsule won't be quite on top of the SRBs
and the vibration problem should be mitigated a bit more.
[quote]
All parties agree that a
heavy-lift launcher is needed for any human space program beyond LEO.
Because of the economies of
scale inherent to the design of launch vehicles,
Economies of scale would be much better served with one launch vehicle
in production, instead of two.
[/quote]
Agreed. And economies of scale don't appear to be quite as important as
complexity.
[quote]Brian
[/quote]
--
Greg Moore
Ask me about lily, an RPI based CMC. |
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| Yama... |
| Posted: Mon Nov 09, 2009 1:55 am |
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Guest
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Brian Thorn <bthorn64 at (no spam) suddenlink.net> wrote:
: On Thu, 5 Nov 2009 12:21:03 +0000 (UTC), Yama
: <tjama at (no spam) NOSPAMpajuoulu.fi> wrote:
: >: Two Ares V-Lites offer *more* payload than an Ares V and an Ares I,
: >: and because both launchers are identical both pads can be the same,
: >: simplifying ground handling and launch preparations. Dumping Ares I
: >: for Ares V-Lite improves the situation, rather than limiting it.
: >
: >It will also mean smaller and individually less capable mission modules,
: It does no such thing. Orion and Altair on one Ares V-Lite, the EDS on
: the other.
Except that Ares V Lite can't do that. It can't launch both Orion and Altair on
one launch.
: >and less capability for direct cargo missions.
: Not with orbital refueling.
....and there go the cost savings.
: >"The recommendation in favor of the dual-launch "Ares-5 Lite" approach as the baseline
: >for lunar missions is difficult to understand. It violates the CAIB recommendation
: >(and many similar recommendations) to separate crew and cargo in whatever post-Shuttle
: >human space transportation system is to be developed.
: Which was a very bad, very knee-jerk recommendation, poorly justified.
I disagree. Manned-only launch keeps things simple. Simple is good.
: >Finally, the Ares-5 Lite is nearly as expensive to develop as the Ares-5,
: Not by a long shot. No new SRB design is needed at all, for starters.
Except that 5-segment booster isn't quite ready yet and needs plenty of development,
which are part of the Ares I development costs. I'm again not getting the logic of
cancelling Ares I to save on development cost of 5-segment booster, which has to be
developed anyway for Ares V Lite.
: No RS-68B development is needed (use SSME, which NASA is reconsidering
: anyway).
Actually they planned to use RS-68A for Ares V Lite. SSME is complicated and
expensive.
: >Not to mention, are you going to use Ares V Lite to launch crews to the
: >ISS?
: Only for the test flights.
I was kidding of course - by the time Ares V lite comes around, ISS will be on its
last legs or deorbited. That is one of the problems of Ares V lite concept - spaceflight
gap will be doubled or tripled.
Operationally, hand that task over to
: SpaceX or another commercial provider, who are chomping at the bit for
: the job.
So you would develope second launcher after all?
I'm getting really puzzled where from these supposed cost savings are meant to come.
Outsourcing the job might reduce the costs somewhat, but not by order of magnitude.
: >Meanwhile, you are mucking around doing missions
: >which cost a lot, yet do little to actually advance the cause for manned Mars
: >mission.
: Except build confidence, reestablish deep space operations, prove
: long-duration life support beyond reach of resupply, demonstrate
: radiation protection. Retiring a great amount of risk before taking
: the final step to the surface of Mars is no small accomplishment.
Much of that could be easily achieved by unmanned test mission done while
actual mission is being prepared.
: >: A couple of development missions (which could be used to launch
: >: satellites or cargo to the Space Station as their primary objective)
: >: eats up all the savings of full-scale development and, say ten years
: >: of Ares V launches? I don't think so. And we just happen to have a
: >: Space Station up there just waiting to take on an experiment like
: >: that.
: >
: >This is pretty goofy logic. Apparently, cost of developing
: >a 5.5 segment booster from 5-segment booster
: ...and RS-68B, and 33-ft tankage, and a new freighter to haul the
: stage to KSC, and a new Crawler with a reinforced Crawlerway to handle
: the weight, and sacrificing Orion reusability because Ares I can't
: handle the weight of the original Orion, and cutting Orion from 6 to 4
: crew because Ares I can't handle the original Orion...
: Not that 5.5 segment is going to be cheap. Look at 5 segment's high
: cost, and how everyone is crying that Ares I-X was nothing because the
: four segment SRB is too different than the five segment SRB. The same
: will be true of 5.5 segment SRB. A couple of dedicated Centaur flights
: would undoubtedly be cheaper than 5.5 segment SRB development.
Yes, all of that is indeed going to be much cheaper than developing whole new
modules with whole new technology, and much less risky. Constellation is not
going to be threatened by technical risk of developing new freighter for Ares V
lower stage. It can be if the untried refuelling technology fails or is delayed.
Both the ship and the crawler have to be refurbished or replaced at some point
in any case.
: >is too high, but
: >developing whole new technology, with several dedicated test missions,
: Technology with a potential huge payoff for a great number of
: customers, versus just NASA's manned program. We could very possibly
: get a commercial partnership (ULA) to cost-share this technology. And
: again, not necessarily dedicated test missions: Two Space Station
: resupply missions could sacrifice a little payload to the prop
: transfer demo hardware. These missions already have rendezvous and
: docking capability.
....and if the technology fails, or is severely delayed, your entire architecture
is blown.
What service missions are you talking about, btw? Progress, or ATV? Dragon will not
have orbital rendezvous and automatic docking capability.
: Contract out the refueling missions to the lowest bidder. SpaceX would
: love the job. There are other low-cost launcher ideas out there that
: just need a market case to get the necessary capital investment. Fuel
: to LEO would be a substantial market. It might even justify a true
: RLV, which would help everybody.
Awfully lot of "could, may, might" there. That doesn't cut it. Any alternative
for Ares I/V architecture would be interesting only if it cuts both technical risks
and costs. Orbital refuelling schemes are very dubious in the latter and definite
no in the former. Hence, I see no reason adopting them. |
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