Author Topic: What should the Flexible Path include?  (Read 24605 times)

Offline JohnFornaro

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What should the Flexible Path include?
« on: 01/14/2010 01:27 PM »
Over on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg524842#msg524842

Bernie Roehl posted what I consider to be an excellent summary of how the Flexible path could be implemented.  I include it here:

<<
First launch of Jupiter/Ares:
  * the biggest launch vehicle in the world (by far)
  * the vehicle that will take mankind to the moon, Mars and beyond
  * the dawn of the next space age

First crewed launch of Orion:
  * the rebirth of American human spaceflight
  * the first flight of the spacecraft that will take us out into deep space
  * the beginning of a new era of exploration for all of mankind

First circumlunar flight:
  * returning to the moon for the first time in half a century
  * shake-down flight of the spacecraft that will take us into the solar system

First visit to L2:
  * the farthest out into space that any human being has ever gone
  * going beyond the moon for the first time
  * visiting the staging ground for all future deep-space missions

First L2 base:
  * building humanity's first deep-space outpost
  * the first step in man's expansion into the solar system
  * the gateway to the moon, the asteroids and the planets

First NEO mission:
   * first human visit to an asteroid
   * first trip out into the solar system
   * farthest into space that any human being has ever gone (by far)
   * longest deep-space mission ever
   * preparation for future trips to the moons of Mars
   * learning more about possible future threats to human civilization
   * developing techniques to prevent future disasters

Lunar landing mission:
   * mankind's triumphant return to the moon
   * studying how to live on the moon so we can move on to Mars
   * finding ways of using the moon's resources for future missions

Phobos visit:
   * first mission to Mars
   * first landing on the moon of another world
   * preparation for an eventual human landing on Mars
>>

Comments?
Sometimes I just flat out don't get it.

Offline khallow

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Re: What should the Flexible Path include?
« Reply #1 on: 01/14/2010 01:33 PM »
What would be good choices for NEOs to visot? Are these just targets of opportunity, that is, pick a time frame then pick an asteroid that you can reach with your delta v in that time frame? Or are there certain targets that are naturally high value, like say 433 Eros?
Karl Hallowell

Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #2 on: 01/14/2010 01:39 PM »
I'm just wondering if one of my old favorites, a manned Venus orbital flight (with telerobotic exploration) might also fit in there somewhere... Before or after Phobos?

Manned Venus orbital mission:
* first manned flight to Venus
* exploring Earth's twin
* telerobotic exploration of a hostile planet and exotic atmosphere
* studying the causes and effects of catastrophic GHG-induced Climate Change in order to prevent their happening on Earth (included that one to appease / incite the Greenies)
* and maybe: first all-solar-powered spacecraft! (would certainly work better at Venus than Mars... I'm not saying that Orion-Venus would have a solar-electric drive, but SOLAR could certainly be hyped in the media)
« Last Edit: 01/14/2010 01:44 PM by ChrisSpaceCH »

Offline Mark S

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Re: What should the Flexible Path include?
« Reply #3 on: 01/14/2010 02:01 PM »
I would limit Flexible Path missions to destinations within Mars' orbit, for a couple of reasons.  First, that's already a pretty good chunk of the Solar System, it should be able to keep us busy for a few decades.  Second, until people are comfortable with nuclear powered space vehicles, we will be limited to solar arrays for onboard power.  Third, also for lack of nuclear power, we are limited to chemical rockets and their low Isp.  Fourth, we still don't understand the full consequences of long term exposure to deep space radiation, and mitigation thereof.

Also I think the very definition of Flexible Path limits human visitations to very small bodies, and I don't think the Moon will initially fall into that category.  We can use FP to build up our experience and space infrastructure, but Moon (and Mars) will require additional development over and above FP.  Basically, if you need a lander, then it would be off limits.  This leaves fly-bys, orbital missions, Mars' moons, NEO's, and possibly the occasional comet if we are able to react quickly.

Finally, I don't think we should plan any manned missions to the L1/L2 points just for the purpose of checking them off our list.  Sure, if we're going to set up a station or man-tended depot, but not just to fly out there, take a few pictures of some empty space, then come back with basically nothing.  That would indeed be a "mission to nowhere", and leave NASA open to more criticism than usual for "wasting taxpayers' money".

Mark S.

Offline khallow

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Re: What should the Flexible Path include?
« Reply #4 on: 01/14/2010 02:15 PM »

Second, until people are comfortable with nuclear powered space vehicles, we will be limited to solar arrays for onboard power.  Third, also for lack of nuclear power, we are limited to chemical rockets and their low Isp.

There's also SEP, solar electric propulsion. It's not a clearly superior system, but it has advantages that make it an interesting and useful rival to chemical propulsion.
Karl Hallowell

Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #5 on: 01/14/2010 06:11 PM »
Chuck wrote about the suggestion of Ceres as a possible Flexible Path destination:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg524939#msg524939
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Offline dad2059

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Re: What should the Flexible Path include?
« Reply #6 on: 01/14/2010 06:41 PM »
I'm just wondering if one of my old favorites, a manned Venus orbital flight (with telerobotic exploration) might also fit in there somewhere... Before or after Phobos?

Manned Venus orbital mission:
* first manned flight to Venus
* exploring Earth's twin
* telerobotic exploration of a hostile planet and exotic atmosphere
* studying the causes and effects of catastrophic GHG-induced Climate Change in order to prevent their happening on Earth (included that one to appease / incite the Greenies)
* and maybe: first all-solar-powered spacecraft! (would certainly work better at Venus than Mars... I'm not saying that Orion-Venus would have a solar-electric drive, but SOLAR could certainly be hyped in the media)

IMO, I would suggest that this be a near-term "flagship" mission, say around 2025-2029 time-frame after a NEO mission(s).

Especially if we're stuck with solar power exclusively for a while.
NASA needs some good ol' fashioned 'singularity tech'

Offline kraisee

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Re: What should the Flexible Path include?
« Reply #7 on: 01/14/2010 06:55 PM »
What would be good choices for NEOs to visot? Are these just targets of opportunity, that is, pick a time frame then pick an asteroid that you can reach with your delta v in that time frame? Or are there certain targets that are naturally high value, like say 433 Eros?

NEO missions are definitely "targets of opportunity".   There is a whole list, with some of the best opportunities occurring roughly once every 18 months or so (on average).

There are some targets closer to home than others, and those are probably what we're after for the early missions, but as the capabilities are proven we will be able to venture further and further away, with Phobos being a sensible mid- to long-term 'goal' in this particular exploration effort.

Ross.
« Last Edit: 01/14/2010 07:00 PM by kraisee »
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Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #8 on: 01/14/2010 06:58 PM »
What is the delta-V to Ceres orbit from EML2? ESL2? I understand it is out of the plane of most of the planets, so couldn't a lunar flyby considerably lower the necessary delta-v? What about Venus or Earth or even Mars gravity assists?

I have seen pork-chop plots of the delta-V requirements of a visit to Ceres, but never anything that takes advantage of gravity assists (or from a Lagrange point).
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Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #9 on: 01/14/2010 07:30 PM »
Nobody likes Venus? :(

Offline Lambda-4

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Re: What should the Flexible Path include?
« Reply #10 on: 01/14/2010 07:36 PM »
Nobody likes Venus? :(

As a flyby add-on on a opposition class Mars orbital mission, yes. As a target of its own for a manned space mission, no, not worth it.
« Last Edit: 01/14/2010 07:36 PM by Lambda-4 »

Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #11 on: 01/14/2010 07:55 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 
Enjoying viewing the forum a little better now by filtering certain users.

Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #12 on: 01/14/2010 07:58 PM »
Nobody likes Venus? :(

As a flyby add-on on a opposition class Mars orbital mission, yes. As a target of its own for a manned space mission, no, not worth it.

I beg to differ. Venus is much less well explored than Mars, which gives us potentially more knowledge gain from an equal-length telerobotic mission that would be possible at Mars.

Plus, if we are seriously contemplating settling the Solar System with humans one day, we really should explore Venus' upper atmosphere (50 km above ground) in detail. The one place (other than Earth) where you could go outside in shirtsleeves without a thermally insulated pressure suit (you'd still need a breathing mask, ofc)

Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #13 on: 01/14/2010 08:02 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Would I like it to go faster? Definately. But nothing happening for 15 years? No, I don't agree. We should still get:
- 10 more years of ISS, with some time (finally!) to do some real work once the construction is over
- new launch vehicle (hopefully DIRECT or something close)
- new spacecraft (Orion)
- hopefully some cool unmanned stuff
« Last Edit: 01/14/2010 08:03 PM by ChrisSpaceCH »

Offline robertross

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Re: What should the Flexible Path include?
« Reply #14 on: 01/14/2010 08:08 PM »
Nobody likes Venus? :(

As a flyby add-on on a opposition class Mars orbital mission, yes. As a target of its own for a manned space mission, no, not worth it.

I beg to differ. Venus is much less well explored than Mars, which gives us potentially more knowledge gain from an equal-length telerobotic mission that would be possible at Mars.

Plus, if we are seriously contemplating settling the Solar System with humans one day, we really should explore Venus' upper atmosphere (50 km above ground) in detail. The one place (other than Earth) where you could go outside in shirtsleeves without a thermally insulated pressure suit (you'd still need a breathing mask, ofc)

You're kidding, right?

Maybe for daredevil explorers who want to try stuff like that, but you don't get all that much from exploration, even science, from skimming the atmosphere. If that was a mission, its intent would be for surface goals, goals that cannot be met even in 50 years.

Gathering atmospheric & surface samples from teleoperated robots (to reduce mission risk), would be the limits for the most part. Add a communications relay satellite on top of that, and that would be a mission.
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Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #15 on: 01/14/2010 08:12 PM »
Gathering atmospheric & surface samples from teleoperated robots (to reduce mission risk), would be the limits for the most part. Add a communications relay satellite on top of that, and that would be a mission.

Yes, this is what I meant. The astronauts stay in Venus orbit, controlling the teleoperated robots on the surface and the robotic blimps in the atmosphere.

Offline robertross

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Re: What should the Flexible Path include?
« Reply #16 on: 01/14/2010 08:16 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Yes, and that was a valid concern/fear during the Augustine Commission's announcement on this front. You need to set fixed and real goals, ones that draw inspiration from the public. It's one of the reasons I believe having a target like Mars is so important.

1) Flyby
2) Phobos-Grunt landing
3) Eventual Mars landing

In there, before, during, and after, you have other destinations like NEOs, the moon, maybe even a Venus fly-by concurrently on the return leg of a Phobos-grunt mission.

And I still think having the moon as a 'fallback' position is important in case funds dwindle, perhaps due to change of policies or political leadership. We can assume a 'tightening of the reigns' in the projects' lifetime, and we should be prepared for it, as should the architecture. This is where commercial entities could step in, much like ISS re-supply.

Important goals (partial):

1) Common docking port type.
2) Multiple docking ports.
3) Emergency re-supply from various entities, depending on launch availability.
4) Rescue mission support in Lunar orbit, both from a launch vehicle standpoint launched from Earth, and a ascent module from the lunar surface. This could be 1-2 person for injuries as a minimum, to full evac capability due to solar storms.
Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

Offline robertross

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Re: What should the Flexible Path include?
« Reply #17 on: 01/14/2010 08:17 PM »
Gathering atmospheric & surface samples from teleoperated robots (to reduce mission risk), would be the limits for the most part. Add a communications relay satellite on top of that, and that would be a mission.

Yes, this is what I meant. The astronauts stay in Venus orbit, controlling the teleoperated robots on the surface and the robotic blimps in the atmosphere.

Cool.  :)
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Offline robertross

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Re: What should the Flexible Path include?
« Reply #18 on: 01/14/2010 08:24 PM »
Another thought we should all ponder:

If Obama is to announce an international effort to return to the moon, what will be the goals? Flags & footprints barely cut it after the first 2-3 landings.

I'm wondering if this could have an energy-related goal? Solar panels or reflective mirrors on the surface, beaming back to Earth?

As to human-related effects, like partial-g effects over long term, since we lost the capability of a large centrifuge on the ISS? Or maybe non-human effects, like plant growth or clean room/sterile environments? Knowledge for a future Mars landing? (My personal thought/preference).

Or maybe just to advance ourselves, and to set a goal to bring our economies back from the brink, with a goal with 'feel-good' moments.
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Offline Lambda-4

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Re: What should the Flexible Path include?
« Reply #19 on: 01/14/2010 09:00 PM »
Gathering atmospheric & surface samples from teleoperated robots (to reduce mission risk), would be the limits for the most part. Add a communications relay satellite on top of that, and that would be a mission.

Yes, this is what I meant. The astronauts stay in Venus orbit, controlling the teleoperated robots on the surface and the robotic blimps in the atmosphere.

Sorry, but that is just not worth it. Teleoperated robots is a nice gadget that people chip in these days to justify orbital missions of Mars, Venus and some even the Moon - but it just doesn't work out. You still need your science team on Earth behind you working out the next steps. For the MERs there is a reason why the team has several dozens of engineers and scientists still engaged in the project. One person alone might make very small decisions more quickly with a teleoperated rover and apply procedures like taking samples and doing analysis of them more quickly, but these are the exact things that semi-autonomous robotics are going to provide for us in the next 20 years anyway.

Considering the expected lifespan of a surface robotic mission on Venus (even with today's technology) an add-on flyby to a Mars orbital mission with some teleoperating for 1-2 days maybe makes sense, but not an orbital mission of its own. Such a mission would cost many billions of dollars, enough to send 10-20 robotic missions to Venus.

Offline robertross

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Re: What should the Flexible Path include?
« Reply #20 on: 01/14/2010 09:19 PM »
Gathering atmospheric & surface samples from teleoperated robots (to reduce mission risk), would be the limits for the most part. Add a communications relay satellite on top of that, and that would be a mission.

Yes, this is what I meant. The astronauts stay in Venus orbit, controlling the teleoperated robots on the surface and the robotic blimps in the atmosphere.

Sorry, but that is just not worth it. Teleoperated robots is a nice gadget that people chip in these days to justify orbital missions of Mars, Venus and some even the Moon - but it just doesn't work out. You still need your science team on Earth behind you working out the next steps. For the MERs there is a reason why the team has several dozens of engineers and scientists still engaged in the project. One person alone might make very small decisions more quickly with a teleoperated rover and apply procedures like taking samples and doing analysis of them more quickly, but these are the exact things that semi-autonomous robotics are going to provide for us in the next 20 years anyway.

Considering the expected lifespan of a surface robotic mission on Venus (even with today's technology) an add-on flyby to a Mars orbital mission with some teleoperating for 1-2 days maybe makes sense, but not an orbital mission of its own. Such a mission would cost many billions of dollars, enough to send 10-20 robotic missions to Venus.

Does that include sample return missions? We need to be clear about that, for that is what the whole point of manned missions takes into account. You have your 'feel-good' flags & footprints, but it's what you bring back that's all important.

You go on a vacation, you have a great time, but invariably you want to bring something back with you (usually it's the woman buying the trinkets...lol). Of course you bring back photos, but you are there to DO THINGS, even if its the journey there and back.

Here's another point: every time we send a manned capsule up there (Orion, or commerical one), you are practicing orbital ops, refining technology...it's not just to get into space. We have spent a lot of money to stay in orbit on ISS for many months. If we want to understand 1-year missions and their affects on the human body, might as well get a planetary fly-by out of it, no? The results of which can refine just how much Artificial Gravity we will need to endure those long duration missions.

These are all part of our baby steps into space. We are learning.
« Last Edit: 01/14/2010 09:20 PM by robertross »
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Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #21 on: 01/14/2010 09:21 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Would I like it to go faster? Definately. But nothing happening for 15 years? No, I don't agree. We should still get:
- 10 more years of ISS, with some time (finally!) to do some real work once the construction is over
- new launch vehicle (hopefully DIRECT or something close)
- new spacecraft (Orion)
- hopefully some cool unmanned stuff

All of which that go nowhere except for where we've been for the last 30.  Begs the question of why replace it then......
Enjoying viewing the forum a little better now by filtering certain users.

Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #22 on: 01/14/2010 09:24 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Yes, and that was a valid concern/fear during the Augustine Commission's announcement on this front. You need to set fixed and real goals, ones that draw inspiration from the public. It's one of the reasons I believe having a target like Mars is so important.

1) Flyby
2) Phobos-Grunt landing
3) Eventual Mars landing

In there, before, during, and after, you have other destinations like NEOs, the moon, maybe even a Venus fly-by concurrently on the return leg of a Phobos-grunt mission.

And I still think having the moon as a 'fallback' position is important in case funds dwindle, perhaps due to change of policies or political leadership. We can assume a 'tightening of the reigns' in the projects' lifetime, and we should be prepared for it, as should the architecture. This is where commercial entities could step in, much like ISS re-supply.

Important goals (partial):

1) Common docking port type.
2) Multiple docking ports.
3) Emergency re-supply from various entities, depending on launch availability.
4) Rescue mission support in Lunar orbit, both from a launch vehicle standpoint launched from Earth, and a ascent module from the lunar surface. This could be 1-2 person for injuries as a minimum, to full evac capability due to solar storms.

All of which are even further in the future.  Fifteen years before we go anywhere beyond where we have been.  I find that extremely disappointing and question on if I want to spend my time making it happen, because I can virtually promise you it NEVER will with this amount of time. 
Enjoying viewing the forum a little better now by filtering certain users.

Offline robertross

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Re: What should the Flexible Path include?
« Reply #23 on: 01/14/2010 09:27 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Yes, and that was a valid concern/fear during the Augustine Commission's announcement on this front. You need to set fixed and real goals, ones that draw inspiration from the public. It's one of the reasons I believe having a target like Mars is so important.

1) Flyby
2) Phobos-Grunt landing
3) Eventual Mars landing

In there, before, during, and after, you have other destinations like NEOs, the moon, maybe even a Venus fly-by concurrently on the return leg of a Phobos-grunt mission.

And I still think having the moon as a 'fallback' position is important in case funds dwindle, perhaps due to change of policies or political leadership. We can assume a 'tightening of the reigns' in the projects' lifetime, and we should be prepared for it, as should the architecture. This is where commercial entities could step in, much like ISS re-supply.

Important goals (partial):

1) Common docking port type.
2) Multiple docking ports.
3) Emergency re-supply from various entities, depending on launch availability.
4) Rescue mission support in Lunar orbit, both from a launch vehicle standpoint launched from Earth, and a ascent module from the lunar surface. This could be 1-2 person for injuries as a minimum, to full evac capability due to solar storms.

All of which are even further in the future.  Fifteen years before we go anywhere beyond where we have been.  I find that extremely disappointing and question on if I want to spend my time making it happen, because I can virtually promise you it NEVER will with this amount of time. 

So, just sit on the ground and watch Russia keep our astronauts flying, its that it? By 2013, there will be no more shuttles flying, that seems like reality. I don't know what else you want.
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Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #24 on: 01/14/2010 09:39 PM »
Chris, we all love Venus, don't we fellas?  And gals too!  Your briefly stated rationale is flawed.  That V. is less explored than M. is not germane; what we know of V. precludes landing people already, barring unforeseen technical developments.  That the upper atmo my indeed prove viable for an eventual "Cloud City" is fine, but too far away in time, compared to the amount of study already done, and the likely feasibility of the plans for M. already conceived.      

Bernie Roehl suggests, on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg525028#msg525028

that a good definition of "sustainable" might be: "able to sustain public interest in order to ensure that the program continues".  This is in contrast to the idea of "sustainable" as  "being able to make everything you need on site", or "making enough profit on industrial operations so as to pay for everything without federal support"

William Barton sez, on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg524840#msg524840

that Flex Path is generally a good idea because it presents a series of interesting milestones to the American taxpayer, "on the way to Mars", and thus may ensure sustainability because of taxpayer visibility.  As always, YMMV, and budgetary issues will always constrict things significantly.

And yes, the fifteen wait is very troublesome.  I'm opposed to any Lagrangian visits, unless we leave something there.  A small rudimentary fuel depot, for example, meant to be used on the next Flex Path mission.  This would spur development on Robert's suggestions regarding standard docking ports, which would begin enabling resupply, both routine and emergency.  Standard docking ports need to be nearer on the critical path.  At the same time, there's an interpretation which would allow that the current efforts are indeed Flex Path.

I have to disagree with OV:  "All of which that go nowhere except for where we've been for the last 30"  That's the been there, done that argument again, and it is fallacious.  Taken to an extreme, one would conclude no more robotic cars on Mars, right?  Been there, done that.

I'm not at all convinced of any energy related goals, with an eye towards beaming the power back to Earth.  We have plenty of power right here; this would be a funding diversion.  Besides, nukes are in the early stages of making a comeback.  One of the early ISRU goals, as a part of Flex Path should be making solar cells, and cracking water to O2 and H2, I think.

There's a lot of good Flex Path stuff scattered in the most unusual places on this forum.  I'll drag some of it in as I stumble on it.
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Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #25 on: 01/14/2010 09:41 PM »

So, just sit on the ground and watch Russia keep our astronauts flying, its that it? By 2013, there will be no more shuttles flying, that seems like reality. I don't know what else you want.

Pretty much that is it, except shuttles will be done long before 2013.  It's not a matter of what I want, it's reality. 
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Offline Patchouli

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Re: What should the Flexible Path include?
« Reply #26 on: 01/14/2010 09:51 PM »
The flexible path should include research for the following technologies.

Fuel depots and tests of cryogenic fuel transfer in space.

Automated assembly of space structures.

Practice of advance construction techniques in LEO ,GEO and L1.

An example of advance automated space construction.
http://paleo-future.blogspot.com/2007/07/space-spiders-1979.html

It was scifi in 1979 but might be possible now with recent advances in robotics.

Demonstration of artificial gravity.

Small scale proof of concept lunar ISRU this can be completely robotic.

A small station in GEO or lunar L1.

SEP tugs for non time critical cargo.

Expanded commercial partnerships.

An NTR ferry should be included as it can make the Moon and NEOs a lot cheaper while testing engines needed for Mars.

They also should bring in the UK and partner with them on Skylon.

The program should be milestone based vs date based and long term goals allowed to change as new technologies become available.
A good example is how the ESAS CxP architecture is already getting outdated and would be extremely out of date by 2020.


In short it should concentrate on building the first parts of a space infrastructure vs doing Apollo style expeditions.
« Last Edit: 01/14/2010 10:09 PM by Patchouli »

Offline robertross

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Re: What should the Flexible Path include?
« Reply #27 on: 01/14/2010 09:53 PM »

So, just sit on the ground and watch Russia keep our astronauts flying, its that it? By 2013, there will be no more shuttles flying, that seems like reality. I don't know what else you want.

Pretty much that is it, except shuttles will be done long before 2013.  It's not a matter of what I want, it's reality. 

if I had the choice between supporting 'something' rather than 'nothing'...I would chose the former. You have an opportunity to be part of that if you choose. That should be an encourragement, especially to help galvanize those who may feel the same way as you. Let's do something positive, instead of focusing on the negative.

We're knee deep in it. it's time we pulled ourselves out, any way we can.
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Re: What should the Flexible Path include?
« Reply #28 on: 01/14/2010 09:55 PM »

I have to disagree with OV:  "All of which that go nowhere except for where we've been for the last 30"  That's the been there, done that argument again, and it is fallacious.  Taken to an extreme, one would conclude no more robotic cars on Mars, right?  Been there, done that.

That's fine....but here are the differences.  These robotic cars on Mars are there to explore and do things we have never done and places on the surface we have never been. 

In LEO, you're talking about applications for something we know how to do and do it well.  Instead you're throwing out the old bath water to refill the tub with a new launch vehicle and new spacecraft that you hope can be patched into ISS, etc before it has a severe breakdown and on the off chance that in 15 years from now you can actually use the vehicles you designed a generation ago to actually leave LEO.

Sorry to be a downer but it's just the way it is. 
« Last Edit: 01/14/2010 09:56 PM by OV-106 »
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Offline robertross

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Re: What should the Flexible Path include?
« Reply #29 on: 01/14/2010 09:57 PM »
The flexible path should include research for the following technologies:

Fuel depots and tests of cryogenic fuel transfer in space.

A small station in GEO or lunar L1.

An NTR ferry should be included as it can make the Moon and NEO a lot cheaper.

In short it should concentrate on building the first parts of a space infrastructure vs doing Apollo style expeditions.

Or...how about a combination of all those?

A tug/space station.

If we are going back and forth to the moon, why not take advantage of this and have a resident crew, maybe transfer 1-2 via Orion or commercially, to do fundamental research during the transit time. It can also serve as a fuel depot, a Vasmir test bed...lots of neat things.
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Offline Patchouli

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Re: What should the Flexible Path include?
« Reply #30 on: 01/14/2010 10:17 PM »
The flexible path should include research for the following technologies:

Fuel depots and tests of cryogenic fuel transfer in space.

A small station in GEO or lunar L1.

An NTR ferry should be included as it can make the Moon and NEO a lot cheaper.

In short it should concentrate on building the first parts of a space infrastructure vs doing Apollo style expeditions.

Or...how about a combination of all those?

A tug/space station.

If we are going back and forth to the moon, why not take advantage of this and have a resident crew, maybe transfer 1-2 via Orion or commercially, to do fundamental research during the transit time. It can also serve as a fuel depot, a Vasmir test bed...lots of neat things.

I was thinking the Orion could be used as a cabin for the NTR ferry and act as an escape pod.

Think the eagle from space 1999 minus the lander part.

It's probably best to separate the ferry and lander or you end up trying to meet impossible mass budgets.
Plus a do all vehicle would be too costly it would be the shuttle all over again.
Wouldn't be impossible in theory the SASSTO could with refueling in go from LEO land on the Moon and return to Earth.
Even though the SASSTO probably would be a cheap vehicle to build it would really tax the fuel depot for the size of the payload it can land.

Destinations may not just be the moon but GEO as well.

If an NTR ferry never materializes and all we get is the SEP cargo ferry then Orion/Dragon plus a Centaur can still carry crew to all close destinations and still test most ideas.

Use both vehicles for BEO if possible for redundancy.

But then that's the flexible part the entire program should not depend on any one vehicle or technology.
If something doesn't work or is too expensive then replace it with something else or change the plan.
« Last Edit: 01/14/2010 10:25 PM by Patchouli »

Offline MichaelF

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Re: What should the Flexible Path include?
« Reply #31 on: 01/14/2010 10:43 PM »
AIUI, Flex-Path is conceived around the idea that, if you develop and demonstrate the systems and architectures of the actual transportation phase, you can then make a good case for additional funding to develop the actual landing and surface systems.

I.e. "We are regularly conducting circumlunar flights at this time.  Give us $X to develop and deploy a lander and surface habitat".

Makes a much better opening than "give us $Y to develop a new launcher(s), spacecraft, lander, surface hab and conduct the various operations......and we will most likely not see the landing for a decade or so...."

Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #32 on: 01/14/2010 11:01 PM »
A lander can serve as a crew ferry, just not the other way around. You're going to build a lander, might as well have it be a crew ferry (unless the ferry is going to be nuclear or solar powered).

And it won't be meeting impossible mass constraints because it'd refuel in between legs of the journey. 5 km/s (or even a smidgen more... say 5.5 km/s) would be enough for all sorts of missions. The Shuttle is an airplane and a space station and a launch vehicle and a crewed spacecraft (with a limited delta-v for maneuvers in LEO).  A spacecraft like the Apollo lunar module need not have a heat shield or anything like that. A spacecraft can be multi-purpose if those purposes have similar constraints. Apollo 13 showed us that a lunar lander can operate as a sort of cislunar transport (to a limited extent, obviously).

If you have to develop a spacecraft with a large performance envelope, then you can also use that same spacecraft for purposes that require a lesser performance envelope. And, if it's not too technically challenged mass-ratio wise (is a mass-ratio of 3 or 3.5 too much for a hydrolox lander?), you might as well use it from the start for missions with smaller performance requirements, proving it each step of the way for the later, more demanding missions.
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Offline jongoff

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Re: What should the Flexible Path include?
« Reply #33 on: 01/14/2010 11:09 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Well, part of the problem is that we're trying to cram too many things into the budget near-term.  I liked the EELV-based flexible path option, because at least with that one, you had the option of going half-way on the HLV at first (ie just doing the ACES and/or Raptor type upper stage first, then do the bigger first stage later), which would free up more money to do exploration earlier (pre-ISS retirement), and then fund the other part of the HLV upgrade after the ISS money is freed up.  It gave you more wiggle room.

For an SDLV though, you have less flexibility:

-you can't really defer the HLV without losing the infrastructure and workforce
-if you defer commercial crew, you've now pushed it past the point where it has an initial anchor market (ISS) to get its feet under it.  Nobody here likes the idea of using commercial crew launches for exploration missions, greatly increasing the probability that 10 years from now, the US will still have only one way of putting people into orbit.
-if you defer R&D again, you won't have the technologies you need (like long-duration radiation mitigation technologies, propellant transfer, etc) to make beyond-lunar exploration actually practical

In the end of course it will be the most useful stuff (commercial crew and R&D) that will get cut to fund the politically convenient, status quo, HLV work.

~Jon

Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #34 on: 01/15/2010 12:27 AM »
"These robotic cars on Mars are there to explore and do things we have never done and places on the surface we have never been."   The extreme view of BTDT, however, would say that, once these things stop working, we need not send any more.  Been there, done that.

If the argument then morphs into, for example, "but we haven't photographed Mons Olympus from the surface", it is easily countered by adding: "neither have we photographed Mons Malapert from the surface".  So we still need lunar exploration, contrary to BTDT.

Further, the BTDT argument about LEO fails when considering the amount of experience with transferring cyrogenic or kerolox fuels in LEO.  Haven't done that yet, so we should do it once.  Done.  Standard docking procedures?  Do it once, and call it a day.  Again, I'm just taking the extreme view.

Throwing out the old launch vehicle with the bath water is an entirely different argument from BTDT however, and much lamented on this forum.  The bright side is that the DIRECT team was successful in countering this expensive old strategy regarding Ares, although we still don't have the final word on that decision.

And waiting 15 years is problematic, but we don't have to wait that long for Flex Path to begin, at least, even if that's somewhat small compensation.

********

Edited later to try and clarify what I would consider extreme interpretations of BTDT, and what the consequences of those interpretations might be, in order to show that the BTDT argument seems to always fail as a reason why NOT to do some arbitrarily chosen mission.
« Last Edit: 01/15/2010 03:44 AM by JohnFornaro »
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Offline robertross

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Re: What should the Flexible Path include?
« Reply #35 on: 01/15/2010 12:39 AM »
"These robotic cars on Mars are there to explore and do things we have never done and places on the surface we have never been."   The extreme view, however, would say that, once these things stop working, we need not send any more.  Been there, done that.

If the argument morphs into "but we haven't photographed Mons Olympus from the surface", it is easily countered by adding: "neither have we photographed Mons Malapert from the surface".  So we still need lunar exploration.


Well, that assumes we NEED to photograph those locations from the ground, or any location for that matter. I would say certain locations would be key, such as potential landing sites, locations for resources, future exploration sites.

We need to have the objectives set first hand. From there, the path can be laid out in (hopefully) a logical manner.

This is true as well for the destinations for Flexible Path. For Mars, many missions need to be persued, many technological leaps need to be made, before we can even attempt an orbital fly-by, let alone a landing.

And I don't care who doesn't agree with me, but ISS is pivitol in this regard. It can provide many of the learning experiences to accomplish those goals. We are learning the closed water recycling system isn't as foolproof as we would have hoped. Carying spares doesn't help if there is a fundamental flaw in the design. We need to understand & SOLVE these problems before we make potentially fatal mistakes out there, where there is no help around, or no 'free return trajectory', like Apollo 13, in a timely manner.

This is why I also believe lunar ops are important, as a necessary step BEFORE we go to Mars. Even if we had to do a 3-month mission circling between the Earth & the moon, so be it. We will learn how our systems perform long-term in space. If a problem creeps up that we can't deal with, we have an escape route.

test test test...then we move on.
test test test...we move on again.

Of course we can't be so risk adverse here, but we are talking many months in space, not days or weeks.
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Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #36 on: 01/15/2010 03:23 AM »
And waiting 15 years is problematic, but we don't have to wait that long for Flex Path to begin, at least, even if that's somewhat small compensation.

Sorry, but most of your post I didn't understand but particulary this part is just wrong because we do know flexible path won't begin until then.  No one is proposing going anywhere until at least 15 years from now.  That's three presidential election cycles and 6 for congress.  Sure, it'll happen....because we have so much experience with long term programs that plan to do "something someday" surviving those many cycles. 
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Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #37 on: 01/15/2010 03:46 AM »
Should President Obama decides on Flex Path tomorrow, I doubt that he'll stipulate that we won't start on it at all for 15 years.  But I'm not the expert.

Robert, I agree that we will need to photograph certain areas.  But a strict BTDT interpretation wouldn't allow this, and anyway it is not at all what I advocate.  I'm just sayin'...

I agree about the ISS "experience".  And I don't see why there's such serious objection to practicing on and around the Moon largely because of its proximity, remembering that Mars is the ultimate objective.
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Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #38 on: 01/15/2010 04:09 AM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Well, part of the problem is that we're trying to cram too many things into the budget near-term.  I liked the EELV-based flexible path option, because at least with that one, you had the option of going half-way on the HLV at first (ie just doing the ACES and/or Raptor type upper stage first, then do the bigger first stage later), which would free up more money to do exploration earlier (pre-ISS retirement), and then fund the other part of the HLV upgrade after the ISS money is freed up.  It gave you more wiggle room.

For an SDLV though, you have less flexibility:

-you can't really defer the HLV without losing the infrastructure and workforce
-if you defer commercial crew, you've now pushed it past the point where it has an initial anchor market (ISS) to get its feet under it.  Nobody here likes the idea of using commercial crew launches for exploration missions, greatly increasing the probability that 10 years from now, the US will still have only one way of putting people into orbit.
-if you defer R&D again, you won't have the technologies you need (like long-duration radiation mitigation technologies, propellant transfer, etc) to make beyond-lunar exploration actually practical

In the end of course it will be the most useful stuff (commercial crew and R&D) that will get cut to fund the politically convenient, status quo, HLV work.

~Jon

Here are a couple of points though about your comments:

-you can defer HLV and still keep the basic infrastructure if this was the decision being made.  Those costs would be transferred to CxP as overhead, just as they were planning on doing anyway once Shuttle stands-down anyway, and hence why the arguement of killing shuttle to fund CxP was nonsense.  A large percentage of that money would be going to this overhead all along.  However, over time and at lower cost per year you could dismantle much of the infrastructure leaving yourself much more of a blank sheet to start the HLV when you felt was appropriate. 

-Why?  ISS is pretty much assured of going to 2020.  Certainly commercial space could field something by then, right, even if it does get deferred slightly for some reason?  If and when it develops and ISS does finally get decommissioned, what happens to commercial space then?  If they are good enough to go to ISS, why wouldn't NASA use them after for orbital transport?

-R&D and operations go hand-in-hand.  You have to have a program to focus those R&D dollars, otherwise your chance to lose focus increases significantly and the buying power of those dollars decreases significantly.  Just having a lax program of "someday we'll go somewhere" will yield no significant tech to do the job with vague and uncommitted notions and proposals and a hope that someone will develop an operationally feasible radition shield or prop depots. 

Finally, why just picking on HLV?  If HLV isn't the right thing for NASA to be funding, why stop there?  What about ISS itself?  How come Orion isn't a target (afterall, it won't be ready until at least 2014)?  What about the various surface systems proposed, or the upper stages, etc? 

I don't have a problem with your ideas, honestly, but I would request that you stop using my posts as a sounding board that NASA and HLV are always the wrong idea.  We obviously have different opinions and philosophies about how to make this come about.   
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Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #39 on: 01/15/2010 04:12 AM »
All of which that go nowhere except for where we've been for the last 30.  Begs the question of why replace it then......

We replace it because we have to. Shuttle is on the way to retirement.

Again, it doesn't matter if you actually get your money's worth, as long as you spin it to the public in an exciting manner ("look at our cool new rocket, BIGGEST BAAAAAADEST one ever built!!!") Unfortuantely, NASA's spin doctors are notoriously poor.

Offline Namechange User

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Re: What should the Flexible Path include?
« Reply #40 on: 01/15/2010 04:16 AM »
All of which that go nowhere except for where we've been for the last 30.  Begs the question of why replace it then......

We replace it because we have to. Shuttle is on the way to retirement.

Again, it doesn't matter if you actually get your money's worth, as long as you spin it to the public in an exciting manner ("look at our cool new rocket, BIGGEST BAAAAAADEST one ever built!!!") Unfortuantely, NASA's spin doctors are notoriously poor.

Why do we have to replace it?  Please give examples.

I for one think it is very important to get your money's worth and shame on you for not thinking that.  Your excuse for why it is not important is poor and clings to the 'internet age" notion that all people are stupid and that spin doctors and talking heads can manipulate everyone.  Dare I ask if one victim has already fallen?
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Online MP99

Re: What should the Flexible Path include?
« Reply #41 on: 01/15/2010 04:51 AM »
I have trouble with the tele-operation thing. As has been said, robotic autonomy will improve over the next couple of decades.

Is anyone proposing to teleoperate a rover on the Moon? It wouldn't be as real-time as a computer game, but a three-second lag is worlds away from the infrequent bursts of comms available to the Mars rovers.

What sort of dish would be required on Earth to give continuous rover comms (whilst the Moon is above the horizon)?

cheers, Martin

Offline gladiator1332

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Re: What should the Flexible Path include?
« Reply #42 on: 01/15/2010 04:58 AM »
I think the biggest mistake we could make right now is taking one giant leap for mankind forward again. As space enthusiasts it is our nature to want to conquer to solar system by next Tuesday, but we need to keep in mind what way forward is best for exploration with the limited resources made available.

I think we need to take baby steps forward.

I think where ever possible, we need to get the smaller companies on the cutting edge of the horizon. If we think we need a lunar lander in the next decade, get SpaceX or Orbital, or any of the other small companies, working on some ideas. That way when the time comes, we already have some useful data and some ideas on paper. Use a COTS like program to develop some of the technologies and infrastructure we will need in the future, that way when the time comes to build a lunar lander, we aren't starting from square one. The same could go for a Space Tug, fuel depots, etc.


Offline Blackout

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Re: What should the Flexible Path include?
« Reply #43 on: 01/15/2010 05:25 AM »
I think a few important things are getting lost in the details here.  The first is that as soon as you have the long term in-space hab built, you can just pick whatever targets are convenient at the time to go to.

NEO's and Planetary flyby's will require the same equipment.  No NEO's nearby for a couple years?  Not ready yet to land on Phobos?  Thats cool, fly around Venus.  No one has done it before and imagine the photo op for NASA to continue public support.  Four astronauts all pictured in front of a window with Venus lit by the sun outside.

You could also flyby Mars with essentially the same equipment.  This is why Flexible Path is comparatively cheap to expensive landing sorties.  Once you have the HLV/EDS/Orion/HAB you have many, many targets to go to without additional expensive development projects.

Also before the Hab is ready (hopefully provided by international partners, otherwise this is just an American affair) you can go to L1/L2, and assemble big telescopes that will find and even image earth-like extra solar planets.  Think MER is popular?  Wait until we find a possible second earth.  All these things will help build support to get more funding.


The second thing that seems to be forgotten is that Flexible Path is 'Flexible' because of available off ramps.  If these amazing new mile stones are successful in drumming up support and more money, then all we need to add to get humans on Mars is a lander/ascent vehicle.  Same with the Moon.  Which means the time from the decision of "land on Mars" to actually happening will be relatively short.  I mean if the Hab and HLV already exist, we just need a lander, MAV, and a second hab/propulsion module to be put in Mars orbit ala DRM 3.0. 


Offline ChrisSpaceCH

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Re: What should the Flexible Path include?
« Reply #44 on: 01/15/2010 07:28 AM »
Why do we have to replace it?  Please give examples.

We have to replace it because the descision has been taken to retire the Shuttle and that descision is irreversible. Do I think it's a good descision? No. Do I think it should not have been taken? Yes. But it's no use to cry about what has been said and done. The boss has decided. We have to accept that and work from here. The only alternative now would be not to replace it at all and end goverment-sponsored HSF. That's still a possibility, btw, although I think the political risks associated with that have greatly diminished the chance of this being chosen (and if it were, that doesn't mean that commercial HSF is going to work...)

Quote
I for one think it is very important to get your money's worth and shame on you for not thinking that.

We'll, first of all, I'm not a US taxpayer, so it's not my money... ;)

Please understand this: I am a rather sarcastic and cynical person, who works in goverment and is therefore "used" to seeing waste of money and inefficiency. Do I think this is good? No. Do I agree with it? Not really. Am I fighting to change this? No, because there's no use. I learned to live with it and make the best of it. And, with time, you learn to play the system and use it to further your own ends, always understanding that you could probably get much better in an "ideal world", but we happen to live in the real world.

Quote
Your excuse for why it is not important is poor and clings to the 'internet age" notion that all people are stupid and that spin doctors and talking heads can manipulate everyone.

Are all people stupid? No, of course not. But, unfortunately, many are misinformed and manipulated by media, and it's getting worse. Is this good? No, but it's the way it is. What to do? See above.

Have I fallen? Maybe. Does that mean I am wrong? If so, we can agree to disagree.

I just think that flexible path is the path that will end up being chosen for political reasons (not just the budget, but also because "landing on the moon" sounds too much like G. W. Bush) and that this is not such a bad thing, since, if you play your cards right, you could actually do quite a bit of "telegenic" stuff that could be sold to the public and rekindle their interest in HSF, which, I'm sorry to say, the Shuttle (and associated false promises) has essentially destroyed.
« Last Edit: 01/15/2010 07:55 AM by ChrisSpaceCH »

Offline William Barton

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Re: What should the Flexible Path include?
« Reply #45 on: 01/15/2010 08:39 AM »
Chris, we all love Venus, don't we fellas?  And gals too!  Your briefly stated rationale is flawed.  That V. is less explored than M. is not germane; what we know of V. precludes landing people already, barring unforeseen technical developments.  That the upper atmo my indeed prove viable for an eventual "Cloud City" is fine, but too far away in time, compared to the amount of study already done, and the likely feasibility of the plans for M. already conceived.      

Bernie Roehl suggests, on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg525028#msg525028

that a good definition of "sustainable" might be: "able to sustain public interest in order to ensure that the program continues".  This is in contrast to the idea of "sustainable" as  "being able to make everything you need on site", or "making enough profit on industrial operations so as to pay for everything without federal support"

William Barton sez, on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg524840#msg524840

that Flex Path is generally a good idea because it presents a series of interesting milestones to the American taxpayer, "on the way to Mars", and thus may ensure sustainability because of taxpayer visibility.  As always, YMMV, and budgetary issues will always constrict things significantly.

And yes, the fifteen wait is very troublesome.  I'm opposed to any Lagrangian visits, unless we leave something there.  A small rudimentary fuel depot, for example, meant to be used on the next Flex Path mission.  This would spur development on Robert's suggestions regarding standard docking ports, which would begin enabling resupply, both routine and emergency.  Standard docking ports need to be nearer on the critical path.  At the same time, there's an interpretation which would allow that the current efforts are indeed Flex Path.

I have to disagree with OV:  "All of which that go nowhere except for where we've been for the last 30"  That's the been there, done that argument again, and it is fallacious.  Taken to an extreme, one would conclude no more robotic cars on Mars, right?  Been there, done that.

I'm not at all convinced of any energy related goals, with an eye towards beaming the power back to Earth.  We have plenty of power right here; this would be a funding diversion.  Besides, nukes are in the early stages of making a comeback.  One of the early ISRU goals, as a part of Flex Path should be making solar cells, and cracking water to O2 and H2, I think.

There's a lot of good Flex Path stuff scattered in the most unusual places on this forum.  I'll drag some of it in as I stumble on it.

John, I usually include high-Venus orbit with teleoperated rovers on my list of "Waypoints to Mars" because it's a variant goal that fits well in the extending timeline paradigm for mission types. Venus is a laudable goal for research, both manned an unmanned, but a pretty difficult target for sample return missions of any sort. One thing I would suggest is a teleoperated+autonomous Venus Science Laboratory, which would be launched by its own HLLV. A rover would collect samples and deliver them to the science lab, which would be operated from Earth most of the time, but realtime for a period of one month by the HVO flexpath crew. Yes, it would be an "enhanced-science stunt," but when you get right down to it, *all* space exploration, including all the cute little "toy cars on Mars" rovers, are just stunts. None of it has a good economic or scientific rationale, unless we serendipitously discover a crashed alien FTL starship somewhere in the solar system. What's the taxpayer return on MER, other than a sense of "way-cool?" The answer is, unprecendentedly glorious careers for a handful of space scientists. The taxpayer gets "way-cool" and Venus is as "way-cool" as anything else. Otherwise, taxpayer gets to tell the scientists to pass the hat and get their own "toy cars on Mars" money.

Offline khallow

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Re: What should the Flexible Path include?
« Reply #46 on: 01/15/2010 10:06 AM »

None of it has a good economic or scientific rationale, unless we serendipitously discover a crashed alien FTL starship somewhere in the solar system.

What makes you think that? First, MER gave us and was expected to give us significant new knowledge about the environment of Mars. That's the scientific rationale. Whether you or this hypothetical "taxpayer" thinks that is a "good" rationale is a different story.

Second, if we're to do anything significant on Mars, say like colonize it (which is in itself could become a second Earth over a few millennia), then knowledge of the environment through missions like this is a necessary precondition. Huge potential future economic benefit enabled by a current mission. There's your economic rationale. Once again, whether that rationale is "good" is a matter of taste.

My view is that if the only real rationale for a publicly funded mission is that it is "way-cool", then don't do it. But you know what? That's my viewpoint, just as your viewpoint was yours, not some generic taxpayer's.

Finally, how do you find crashed alien FTL starships? Hope one lands in your backyard? Given that we don't have an obvious starship in a museum or government lab (to my knowledge, of course) already, it sounds to me like you'd need to look for that sort of thing in order to find it.
« Last Edit: 01/15/2010 10:07 AM by khallow »
Karl Hallowell

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Re: What should the Flexible Path include?
« Reply #47 on: 01/15/2010 11:22 AM »

None of it has a good economic or scientific rationale, unless we serendipitously discover a crashed alien FTL starship somewhere in the solar system.

What makes you think that? First, MER gave us and was expected to give us significant new knowledge about the environment of Mars. That's the scientific rationale. Whether you or this hypothetical "taxpayer" thinks that is a "good" rationale is a different story.

Second, if we're to do anything significant on Mars, say like colonize it (which is in itself could become a second Earth over a few millennia), then knowledge of the environment through missions like this is a necessary precondition. Huge potential future economic benefit enabled by a current mission. There's your economic rationale. Once again, whether that rationale is "good" is a matter of taste.

My view is that if the only real rationale for a publicly funded mission is that it is "way-cool", then don't do it. But you know what? That's my viewpoint, just as your viewpoint was yours, not some generic taxpayer's.

Finally, how do you find crashed alien FTL starships? Hope one lands in your backyard? Given that we don't have an obvious starship in a museum or government lab (to my knowledge, of course) already, it sounds to me like you'd need to look for that sort of thing in order to find it.


You're mixing up three things:

1. Please tell me how you quantify the value of the scientific return from MER.

2. Explain again how the living taxpayer will benefit by the colonization of Mars in some imaginary science fiction future.

3. "Crashed alien starships" is a form of illustration by humor. And please do look up words you may not know. "Serendipitously" refers to the making of accidental fortuitous discoveries. So obviously, we can't go looking for them. (Footnote: "The Three Princes of Serendip.")

Offline Ben the Space Brit

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Re: What should the Flexible Path include?
« Reply #48 on: 01/15/2010 11:45 AM »
IMHO, "Flexible Path" means "Let's build the HLV and transfer vehicle first and worry about the final destination once it is clearer what budget and destingations are avaialble at that time."  That is okay in theory only if you can be sure of mmaintaing political interest until you reach that point.  I, for one, am a sceptical about that.

This is why I always thing that some destination is needed with a clear objective.  We cannot go to a point, just to go (although I'm sure that milestones, so long as they have pretty pictures, will impress the more sympathetic members of the press corps).  This is what William is doing with his 'Venus HERRO' idea.  At least something is perceptable as being achieved.  I also suspect that is what is behind NASA's embryonic NEO encounter program.

FWIW, I personally advocate a EML-1 or -2 destination station in place of the lunar surface base.  You can do lots of experiments about life-support systems and radiation shielding with Earth nearby in case of problems.  An EML station with long-term occupation also gives the opportunity for headline-catching things like observing a total eclipse of the sun by the Earth.

Ultimately, however, the objective must be to land on the destination world.  As technically and scientifically inaccurate as it is, people (most importantly, politicians) will not be satisfied that a destination has been truely reached until there are human boot-prints on the surface.

FWIW, my ideas (utilising the 'classic' -130 and -24x version of the DIRECT Jupiter) are something like this.

By 2015
* J-130 operational
* Orion to LEO with SSPDM

   > ISS support
   > Possible other LEO spacecraft maintenance missions (assessed on need closer to time)

By 2020
* J-24x operational
   > First crewed lunar free-return fly-around
   > First crewed lunar orbiter ('Apollo 8 Redux')
* ATV-derived spacelab module operational
   > First LEO test flight of spacecraft

By ISS Retirement + 2.5 years
Spacelab module utilisation
   > LLO short-duration orbiter (BEO test for spacelab)
   > EML Moonlab IOC (two spacelabs docked, initially)
   > First NEO encounter (Orion + ATV-Lab + EDS)

By 2025
* LSAM operational
   > First lunar landing
   > Lunar surface endurance record using cargo lander precursor

By 2030
* MTV Operational
   > Venus orbiter to test aerocapture & Earth return system
   > Phobos orbiter
   > Advanced planning for first Mars landing

Actually, I'd like the first Mars landing to take place before the end of 2030.  However, I'm trying to keep this conservative.

The underlying philosophy of this plan is a series of near-term objectives to keep the politicians focussed.  "What are you doing?" "We are building X." "Why?" "So we can [see objective above]."  By spreading out the development, you also get better utilisation of the budget.  Similarly, farming out, say, the ATV-Lab to ESA and JAXA with the US matching the development cost dollar-for-dollar, costs for the module are reduced.
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Offline khallow

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Re: What should the Flexible Path include?
« Reply #49 on: 01/15/2010 11:47 AM »

You're mixing up three things:

1. Please tell me how you quantify the value of the scientific return from MER.

2. Explain again how the living taxpayer will benefit by the colonization of Mars in some imaginary science fiction future.

3. "Crashed alien starships" is a form of illustration by humor. And please do look up words you may not know. "Serendipitously" refers to the making of accidental fortuitous discoveries. So obviously, we can't go looking for them. (Footnote: "The Three Princes of Serendip.")

1. Irrelevant. Intangible benefits can indeed be good rationales. You  use the "way-cool" argument for a good rationale. That's even less tied to something quantifiable.

2. If the imaginary science fiction future happens in a few decades, or those tax payers live a lot longer than expected. Some taxpayers also have concern for the distant future. For example, anti-nuclear protesters often show concern for harm imposed hundreds of thousands of years from now.

3. Ok, I looked up the definition of serendipity. I was right in my use. Just because something is accidental and unexpected, doesn't mean that you can't look for it. Further, unless the thing in question is blatantly obvious, which most scientific discoveries are not, then you had to be looking for it in some way in order to discover it.
« Last Edit: 01/15/2010 11:47 AM by khallow »
Karl Hallowell

Offline infocat13

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Re: What should the Flexible Path include?
« Reply #50 on: 01/15/2010 12:41 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Well, part of the problem is that we're trying to cram too many things into the budget near-term.  I liked the EELV-based flexible path option, because at least with that one, you had the option of going half-way on the HLV at first (ie just doing the ACES and/or Raptor type upper stage first, then do the bigger first stage later), which would free up more money to do exploration earlier (pre-ISS retirement), and then fund the other part of the HLV upgrade after the ISS money is freed up.  It gave you more wiggle room.

For an SDLV though, you have less flexibility:

-you can't really defer the HLV without losing the infrastructure and workforce
-if you defer commercial crew, you've now pushed it past the point where it has an initial anchor market (ISS) to get its feet under it.  Nobody here likes the idea of using commercial crew launches for exploration missions, greatly increasing the probability that 10 years from now, the US will still have only one way of putting people into orbit.
-if you defer R&D again, you won't have the technologies you need (like long-duration radiation mitigation technologies, propellant transfer, etc) to make beyond-lunar exploration actually practical

In the end of course it will be the most useful stuff (commercial crew and R&D) that will get cut to fund the politically convenient, status quo, HLV work.

~Jon

the above post rings true,How long would the gap be with a Inline HLV
perhaps what will end up coming to pass is the ESA will end up doing the fuel depot mission as it could also be used to augment commercial space by extending the life of communications satillights of their customers.
« Last Edit: 01/15/2010 12:41 PM by infocat13 »
I am a member of the side mount fanboy universe however I can get excited over the EELV exploration architecture fanboy universe.Anything else is budgetary hog wash
flexible path/HERRO

Offline Downix

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Re: What should the Flexible Path include?
« Reply #51 on: 01/15/2010 12:47 PM »
Anyone else have a problem with it being at least 15 years before we actually go anywhere?

I like the idea of flexible path but with the understanding we go somewhere quick and often.  My fear is empty points in space and just meandering around the solar system will not sustain any real support unless it happens much quicker and with more frequency than landing someplace. 

Well, part of the problem is that we're trying to cram too many things into the budget near-term.  I liked the EELV-based flexible path option, because at least with that one, you had the option of going half-way on the HLV at first (ie just doing the ACES and/or Raptor type upper stage first, then do the bigger first stage later), which would free up more money to do exploration earlier (pre-ISS retirement), and then fund the other part of the HLV upgrade after the ISS money is freed up.  It gave you more wiggle room.

For an SDLV though, you have less flexibility:

-you can't really defer the HLV without losing the infrastructure and workforce
-if you defer commercial crew, you've now pushed it past the point where it has an initial anchor market (ISS) to get its feet under it.  Nobody here likes the idea of using commercial crew launches for exploration missions, greatly increasing the probability that 10 years from now, the US will still have only one way of putting people into orbit.
-if you defer R&D again, you won't have the technologies you need (like long-duration radiation mitigation technologies, propellant transfer, etc) to make beyond-lunar exploration actually practical

In the end of course it will be the most useful stuff (commercial crew and R&D) that will get cut to fund the politically convenient, status quo, HLV work.

~Jon

the above post rings true,How long would the gap be with a Inline HLV
perhaps what will end up coming to pass is the ESA will end up doing the fuel depot mission as it could also be used to augment commercial space by extending the life of communications satillights of their customers.
From what I've heard, a Phase 0 w/o upper stage can be flying within 36 months, thanks in part due to the existing history of the design (this would be, what, the 3rd time we've explored the option?).  Phase 1 w/ an RL-10 based upper stage, approx 5 years.  Phase 2 w/ J-2X based upper stage, 2017/2018 area.

Now, the Phase 0 model in some configurations can rival the Saturn for lbs-to-orbit I may remind you.
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Offline William Barton

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Re: What should the Flexible Path include?
« Reply #52 on: 01/15/2010 12:55 PM »

You're mixing up three things:

1. Please tell me how you quantify the value of the scientific return from MER.

2. Explain again how the living taxpayer will benefit by the colonization of Mars in some imaginary science fiction future.

3. "Crashed alien starships" is a form of illustration by humor. And please do look up words you may not know. "Serendipitously" refers to the making of accidental fortuitous discoveries. So obviously, we can't go looking for them. (Footnote: "The Three Princes of Serendip.")

1. Irrelevant. Intangible benefits can indeed be good rationales. You  use the "way-cool" argument for a good rationale. That's even less tied to something quantifiable.

2. If the imaginary science fiction future happens in a few decades, or those tax payers live a lot longer than expected. Some taxpayers also have concern for the distant future. For example, anti-nuclear protesters often show concern for harm imposed hundreds of thousands of years from now.

3. Ok, I looked up the definition of serendipity. I was right in my use. Just because something is accidental and unexpected, doesn't mean that you can't look for it. Further, unless the thing in question is blatantly obvious, which most scientific discoveries are not, then you had to be looking for it in some way in order to discover it.


There's clearly no basis for discussion here. Re: #3. Read the definition again. Although you can "expect the unexpected," in the sense you can anticipate *something* you didn't think of may or may not happen, you can't expect a particular unexpected event. Therefore, if something is accidental and unexpected, you can't go looking for it. Do you get that? If not, try looking up "unexpected."

Footnote: basic science is in some sense done for purposes of serendipity. If you look under a rock to see if anything is there, and there is a bug under it, that's serendipity. If you look under a rock to see if there is a bug under it, and there is, it's not. The presense of the bug is not unexpected.

Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #53 on: 01/15/2010 01:27 PM »
William: To clarify my thoughts for you.  Research about  Venus -- fine.  V. precludes sample returns because they require landings.  In addition, the key point of my brief rebuttal of Venusian exploration was that it be put on the path later, not sooner.  Prioritization is key.  There's billions of dollars worth of missions mentioned just in the few postings above.

Sadly, I think many "generic" "consumers" fall for the "way cool" argument.  If I can slip into my sarcastic mode for a bit; they are perfectly willing to listen to "...press five to leave a callback number; press six to send a numeric page; or simply, hang up..." over and over each day, as long as the keyboard on their phone has a "sexy" layout.  I share Karl's viewpoint on "way cool".

An aside about the alien starships.  While true that finding them is more likely if one is looking for them; it is also true that we have no methodology for looking for alien artifacts.  The problem, as I see it, can be briefly stated thus:  We don't know if there's a needle in the haystack; we don't know which haystack to look in; virtually all of the haystacks are outside of the solar system; we have no idea how old the needle might be; and we don't know if it's a needle that we're looking for.   Wait a minute... what's that silver antenna sticking up in the back yard?

Ben's list is good, although I don't agree with the details totally, but his larger point is, I think, that "sustainability", in the political sense of sustained funding, could be, or might be, maintained with a specific path to follow.  If the path is codified into the legislation, it would seem that the term "flexible" would lose its meaning somewhat.  If the process of determining flexibility could find its way into the legislation, that would be a good thing.
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Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #54 on: 01/15/2010 02:37 PM »
If we're going to send a manned mission to orbit Phobos, you could land on it with the mission margin of your delta-v budget. Your standard reaction control thrusters have more than enough thrust to land your spacecraft there. You might as well plan on landing there. This could be accomplished quite easily, the only limits being whether radiation for that long is an issue and whether exercize can mitigate zero-g effects for long enough that your bones don't turn to goo. An ATV could work as a decent hab.

But as much as I like flex path missions, I think we should develop a lander (single stage, that way the same design could be used as a Mars ascent vehicle) as soon as we can. Altair with the ascent stage engine and tanks deleted (and not performing the TLI burn) is probably close to enough performance already in a single stage, and ironically, it may be cheaper than for a two-stage lander.


 An unmanned sample return mission from Venus would definitely be harder than a manned mission to the surface of Mars. You're essentially having to land a full Earth launch vehicle (along with a launch tower?!) capable of launching interplanetary payloads inside a high-pressure oven, and having it launch effectively (with no ground crew) through an atmosphere at a pressure almost a hundred times denser than ours (comparable to combustion chamber!) after being loaded by an autonomous robot somehow capable of operating for long periods of time in this environment. Oh, and you guys think salt water has a detrimental effect on rocket engines? Try sulfuric acid at 900 degrees F. This mission is virtually impossible. The only reason I say it isn't 100% impossible is that maybe it could be done if launched from a blimp the size of the Hindenberg. It'd cost at least a trillion dollars. Let's explore all the moons of Jupiter, Saturn, Uranus, Neptune, Earth, and Mars first. And land on Mars, Ceres, and Mercury.
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Offline robertross

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Re: What should the Flexible Path include?
« Reply #55 on: 01/15/2010 04:43 PM »
I'm seeing people losing a grasp on what missions need to be accomplished to justify the money being spent. Here's a refresher:

1) It starts with getting us out of desparate economic times. People working = tax revenue = reduced deficits (hopefully).

2) Education: this bring up the standard of living of the people so that more can prosper.

3) Tied into #2: We need to inspire the children, not the parents. Parents listen (or are supposed to listen) to their children. If they are enthusiastic abotu space, their parents will push for it to continue. WIth children wanting to become involved with science, space, technology, we give them a future to be involved with, and hence we need jobs for them when they come out of school.

So, we need missions that not only inspire children, but include them as well. This goes back to something I mentioned a while back: tele-operated robots on the moon operated from schools. How cool is that?

Another point on fly-by missions: If we go to these remote destinations, we should bring about landing beacons to identify prime landing spots. Much easier to cover vast terrain from above, and send down marker beacons, for future manned & unmanned missions. Another reason to get Plutonium production going, since many locations are too isolated to rely on solar power.

We would need a rack-based deployment system, with small RTG-powered radio beacons, mounted to the outside of our spacecrafts.
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Offline hydra9

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Re: What should the Flexible Path include?
« Reply #56 on: 01/16/2010 06:45 AM »
Over on:

http://forum.nasaspaceflight.com/index.php?topic=19548.msg524842#msg524842

Bernie Roehl posted what I consider to be an excellent summary of how the Flexible path could be implemented.  I include it here:

<<
First launch of Jupiter/Ares:
  * the biggest launch vehicle in the world (by far)
  * the vehicle that will take mankind to the moon, Mars and beyond
  * the dawn of the next space age

First crewed launch of Orion:
  * the rebirth of American human spaceflight
  * the first flight of the spacecraft that will take us out into deep space
  * the beginning of a new era of exploration for all of mankind

First circumlunar flight:
  * returning to the moon for the first time in half a century
  * shake-down flight of the spacecraft that will take us into the solar system

First visit to L2:
  * the farthest out into space that any human being has ever gone
  * going beyond the moon for the first time
  * visiting the staging ground for all future deep-space missions

First L2 base:
  * building humanity's first deep-space outpost
  * the first step in man's expansion into the solar system
  * the gateway to the moon, the asteroids and the planets

First NEO mission:
   * first human visit to an asteroid
   * first trip out into the solar system
   * farthest into space that any human being has ever gone (by far)
   * longest deep-space mission ever
   * preparation for future trips to the moons of Mars
   * learning more about possible future threats to human civilization
   * developing techniques to prevent future disasters

Lunar landing mission:
   * mankind's triumphant return to the moon
   * studying how to live on the moon so we can move on to Mars
   * finding ways of using the moon's resources for future missions

Phobos visit:
   * first mission to Mars
   * first landing on the moon of another world
   * preparation for an eventual human landing on Mars
>>

Comments?

Where are you going to get the hundreds of tonnes of mass shielding for a trip to an asteroid, the moons of Mars, and a permanent Langrange point outpost?

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Offline Lambda-4

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Re: What should the Flexible Path include?
« Reply #57 on: 01/16/2010 07:49 AM »

Where are you going to get the hundreds of tonnes of mass shielding for a trip to an asteroid, the moons of Mars, and a permanent Langrange point outpost?

GRE exposure up to 180 days mission length is unproblematic.
SPE shelter is required even for an asteroid mission and SEL-1/2 mission, however this is unproblematic (get half your spacecraft in the direction of the sun, as well as the water tank and scientific equipment and hide behind it)

For a sprint Mars flyby and Mars orbital mission (450-500 days) GRE exposure is above NASA guidelines at Solar minimum. So that would require some polyethylene/water shielding (20-25g per cm²) to get below NASA guidelines for career radiation exposure.

Conjunction class 900 days Mars orbital missions are not viable with current technology due to GRE exposure at Solar minimum - as well as are prohibitive due to long-term microgravity exposure (if not mitigated by AG).

EDIT: some errors
« Last Edit: 01/16/2010 12:26 PM by Lambda-4 »

Offline Ben the Space Brit

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Re: What should the Flexible Path include?
« Reply #58 on: 01/16/2010 10:46 AM »

Where are you going to get the hundreds of tonnes of mass shielding for a trip to an asteroid, the moons of Mars, and a permanent Langrange point outpost?

GRE exposure up to 180 days mission length are unproblematic.

Thank you, Lambda-4 for standing up and pointing out that this particular dragon is, in fact, a cardboard cut out set up by the "Can't, Won't, Mustn't" squad to try to rule out HSF exploration.
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Offline Downix

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Re: What should the Flexible Path include?
« Reply #59 on: 01/16/2010 12:20 PM »

Where are you going to get the hundreds of tonnes of mass shielding for a trip to an asteroid, the moons of Mars, and a permanent Langrange point outpost?

GRE exposure up to 180 days mission length are unproblematic.
SPE shelter is required even for an asteroid mission and SEL-1/2 mission, however this is unproblematic (get half your spacecraft in the direction of the sun, as well as the water tank and scientific equipment and hide behind it)

For a sprint Mars flyby and Mars orbital mission (450-500 days) GRE exposure is above NASA guidelines at Solar minimum. So that would require some polyethylene/water sheltering (20-25g per cm²) to get below NASA guidelines for career radiation exposure.

Opposition class 900 days Mars orbital missions are not viable with current technology due to GRE exposure at Solar minimum - as well as are prohibitive due to long-term microgravity exposure (if not mitigated by AG).
Plus where we'll get it is the same place we get shielding now, from around ourselves.  The technology to bring this into space, the focus on weight-loss, will be of incredible boon to huge sectors of industry. Imagine the possibilities of new lightweight radiation shielding technology. 

It is the gravity issue I am more concerned with, but with the 12m wide fairing for Jupiter you can easily launch an integrated AG system a la USS Discovery.
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Offline Lambda-4

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Re: What should the Flexible Path include?
« Reply #60 on: 01/16/2010 12:29 PM »

It is the gravity issue I am more concerned with, but with the 12m wide fairing for Jupiter you can easily launch an integrated AG system a la USS Discovery.

Vertigo prohibits higher G (above 0.1G) spinning at a 12m structure. It's a lot simpler mass-wise and technology-wise to just have your spacecraft split in two (the propulsion unit on the one end and the hab on the other) with a km long tether (or long rigid structure) and spin it. Doesn't look like Odyssey in Space, but it does the job credibly.

http://galaxywire.net/wp-content/uploads/2009/04/nasa_mars_artificial_gravity_1989.jpg
« Last Edit: 01/16/2010 12:38 PM by Lambda-4 »

Offline William Barton

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Re: What should the Flexible Path include?
« Reply #61 on: 01/16/2010 12:36 PM »
William: To clarify my thoughts for you.  Research about  Venus -- fine.  V. precludes sample returns because they require landings.  In addition, the key point of my brief rebuttal of Venusian exploration was that it be put on the path later, not sooner.  Prioritization is key.  There's billions of dollars worth of missions mentioned just in the few postings above.

Sadly, I think many "generic" "consumers" fall for the "way cool" argument.  If I can slip into my sarcastic mode for a bit; they are perfectly willing to listen to "...press five to leave a callback number; press six to send a numeric page; or simply, hang up..." over and over each day, as long as the keyboard on their phone has a "sexy" layout.  I share Karl's viewpoint on "way cool".

An aside about the alien starships.  While true that finding them is more likely if one is looking for them; it is also true that we have no methodology for looking for alien artifacts.  The problem, as I see it, can be briefly stated thus:  We don't know if there's a needle in the haystack; we don't know which haystack to look in; virtually all of the haystacks are outside of the solar system; we have no idea how old the needle might be; and we don't know if it's a needle that we're looking for.   Wait a minute... what's that silver antenna sticking up in the back yard?

Ben's list is good, although I don't agree with the details totally, but his larger point is, I think, that "sustainability", in the political sense of sustained funding, could be, or might be, maintained with a specific path to follow.  If the path is codified into the legislation, it would seem that the term "flexible" would lose its meaning somewhat.  If the process of determining flexibility could find its way into the legislation, that would be a good thing.

Regarding Venus, I'm just point out it fits in as a waypoint, and might be as worthwhile as, for example, a third NEO mission requiring the same deltaV budget. I agree about "way cool," but think it's probably unavoidable as a "reward" for taxpayers. The alternative pursued in recent decades has been, "give us billions so we can play with our cool toys without you." Then people wonder why that "generic consumer" is disapproving of the space program? My point about the aliens was meant humorously, as an illustration of something it would be pointless to look for using either HSF or robotics. SETI radiotelescopy is about the best we can do. If some current or future space telescope discovers a theoretically habitable world parsecs away, *and* it turns out to be generating radio signal, that would be serendipitous too, because the planet finder is for finding planets, not aliens. And as for the silver antenna, one word: Cartman...

Offline khallow

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Re: What should the Flexible Path include?
« Reply #62 on: 01/16/2010 01:00 PM »

Where are you going to get the hundreds of tonnes of mass shielding for a trip to an asteroid, the moons of Mars, and a permanent Langrange point outpost?

I'm sure if we looked, we could find hundreds of tons of mass shielding here on Earth. Then it's just a matter of putting it into space, which we already know how to do.
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Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #63 on: 01/16/2010 01:52 PM »
Nate:

What's with the 12m fairing?  I thought it was 8.4m.  Could you elaborate?  I, for one, don't quite understand all the permutations.  On some thread, there was a debate about 8.4m versus 10m. 

William:

I get what yer sayin' about V.  Also, "way cool" is pretty much what we'll get, almost no matter the mission.  Obviously, it shouldn't drive mission parameters.  And yes, it sure seems to me that "give us billions so we can play with our cool toys without you" is too prevalent an attitude.  My take on the circumstantial evidence for this is the lack of patience that the "experts" have, when the "novices" ask "Why is this so?" or "Why is that so?".  We see this with the rocket scientists disparaging amateur inquiries, but we also see it in congresscritters disparaging the citizenry.  It is what it is, however.

I know who Cartman is, but what does he have to do with the silver antenna?
Sometimes I just flat out don't get it.

Offline robertross

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Re: What should the Flexible Path include?
« Reply #64 on: 01/16/2010 02:26 PM »
Nate:

What's with the 12m fairing?  I thought it was 8.4m.  Could you elaborate?  I, for one, don't quite understand all the permutations.  On some thread, there was a debate about 8.4m versus 10m. 


PLF (Payload Fairing) is the UPPER part of the rocket that encapsulates the payload. The Jupiter (and shuttle ET) 'core' is 8.4m, but the PLF can grow up to the poinit of stability & performance limits. The Direct team indicates that a 12m PLF is quite possible. This allows you to launch something with greater volume, which is by itself a limiting factor for current launch vehicles.
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Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #65 on: 01/17/2010 11:42 PM »
Thanks Robert.  I'd have to findthe link, but I remember the 10m people arguing quite strenuously with the 8.4m people.  My recollection is that the latter viewed 10m as too big.  How in the heck can 12m now be suggested?
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Offline TrueBlueWitt

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Re: What should the Flexible Path include?
« Reply #66 on: 01/18/2010 12:00 AM »
Thanks Robert.  I'd have to findthe link, but I remember the 10m people arguing quite strenuously with the 8.4m people.  My recollection is that the latter viewed 10m as too big.  How in the heck can 12m now be suggested?

There have been many "Hammerhead" fairings used on various launchers over the years..  Larger fairing diameters are heavier and reduce payload capacity. The NASA engineers within DIRECT ran the aerodynamics and analysis on 12m fairing(on 8.4m core) and found it was viable.  From what I remember, even 15m fairings studied were not deemed beyond the realm of possibility.. although I'd guess at severely reduced lift capacity.

To reduce vertigo and increase G's.. use a Bigelow style inflatable.. this would allow somewhere around a 11m*1.5(inflated).. so potentially 16m+

What's the maximum G force you can create at that diameter without inducing vertigo.
« Last Edit: 01/18/2010 12:00 AM by TrueBlueWitt »

Offline texas_space

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Re: What should the Flexible Path include?
« Reply #67 on: 01/18/2010 01:26 AM »
I've been reading some of the discussions here.  I have a question (especially for those of us here who aren't Americans):
Would a foreign country or countries be willing to fund completely a lander, hab, etc. for a lunar, NEO, Phobos, or Mars mission?

Obviously having an additional module or manned spacecraft (e.g. lander) adds to the costs for manned missions.  As we would need such a module or spacecraft to accomplish such a mission, I think international cooperation could help us achieve goals such as lunar return etc.  My personal opinion is that ESA, RSA, JAXA aren't willing to pony up the euros, rubles or yen to do this.  Partial sharing of costs might not work as US budgets might not allow partial funding, so my thought is that whole platform funding is required.

Thoughts?
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Offline Analyst

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Re: What should the Flexible Path include?
« Reply #68 on: 01/18/2010 06:58 AM »
I think they won't massively increase their HSF budget: HSF is a small niche there even more than it is in the US. The public (the taxpayer) wants to pay only so much.

And the US is not known for keeping its commitments: So they risk having a lunar lander at hand (if they really should start development, see above) with the US having its parts (launch vehicle and other infrastructure) cancelled.

Analyst

Offline Lambda-4

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Re: What should the Flexible Path include?
« Reply #69 on: 01/18/2010 07:48 AM »
I think they won't massively increase their HSF budget: HSF is a small niche there even more than it is in the US. The public (the taxpayer) wants to pay only so much.

I would rather say ESA memberstates don't want to pay more, unless there are really, really big benefits for them. The public in Europe isn't very engaged in space flight.

If I had to guess, I'd say any development project started by ESA (with individual memberstates) in cooperation with NASA for Cx has to be in the ballpark of ATV development or Columbus development financially. That's not much more than EUR 1.5 billion per project (inflation adjusted...) or about USD 2 billion (over about 10 years) or by far not enough for a lunar lander on the scale of the current Altair baseline (45mt). It's very likely also not enough for a simpler (all hypergolics) and smaller (25-30mt?) lunar lander. It might be enough for just one part of the lander (ascent stage) or a part of a lunar architecture (hab) or an independent cargo lunar lander (Ariane 5ME - 1.7mt to the lunar surface http://www.esa.int/esaHS/SEMJRY4DHNF_exploration_0.html).
« Last Edit: 01/18/2010 07:48 AM by Lambda-4 »

Offline William Barton

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Re: What should the Flexible Path include?
« Reply #70 on: 01/18/2010 09:08 AM »
Nate:

What's with the 12m fairing?  I thought it was 8.4m.  Could you elaborate?  I, for one, don't quite understand all the permutations.  On some thread, there was a debate about 8.4m versus 10m. 

William:

I get what yer sayin' about V.  Also, "way cool" is pretty much what we'll get, almost no matter the mission.  Obviously, it shouldn't drive mission parameters.  And yes, it sure seems to me that "give us billions so we can play with our cool toys without you" is too prevalent an attitude.  My take on the circumstantial evidence for this is the lack of patience that the "experts" have, when the "novices" ask "Why is this so?" or "Why is that so?".  We see this with the rocket scientists disparaging amateur inquiries, but we also see it in congresscritters disparaging the citizenry.  It is what it is, however.

I know who Cartman is, but what does he have to do with the silver antenna?

Here's a picture of the Voyager II LV (Titan IIIE/Centaur) with a hammerhead shroud. You can see the fairing is much bigger than the 10ft diameter of the Titan upper stage.

http://www.nasaimages.org/luna/servlet/detail/nasaNAS~5~5~24250~127646:Voyager-2-Launch

Cartman: The alien probe episode.

http://en.wikipedia.org/wiki/Cartman_Gets_an_Anal_Probe

I see here, it was an 80ft antenna!
« Last Edit: 01/18/2010 09:12 AM by William Barton »

Offline kraisee

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Re: What should the Flexible Path include?
« Reply #71 on: 01/18/2010 09:09 AM »
I think there is a fair chance of getting a slight 'bump' to NASA's budget for a year or two, essentially as a stimulus package to help get the agency through this transition period.

But after that, deficit spending is going to dictate NASA's long-term budget -- and that looks to me to be little short of "horrific" in the 5-10 year time-frame.

Ross.
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Offline Downix

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Re: What should the Flexible Path include?
« Reply #72 on: 01/18/2010 10:43 AM »
Thanks Robert.  I'd have to findthe link, but I remember the 10m people arguing quite strenuously with the 8.4m people.  My recollection is that the latter viewed 10m as too big.  How in the heck can 12m now be suggested?
10m tank, nothing to do with fairing.

The tank on an 8.4m can support up to a 12m fairing, hammerhead-style, IIRC.  Useful for those one-off situations, like Altair, where you need a larger fairing.  Also useful to diffuse arguments with people that go "We need a 10m fairing, so we obviously need a 10m tank!"
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #73 on: 01/18/2010 01:10 PM »
Thanks guys.  Ouch on that antenna.
Sometimes I just flat out don't get it.

Offline Norm Hartnett

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Re: What should the Flexible Path include?
« Reply #74 on: 01/18/2010 04:31 PM »
Vertigo prohibits higher G (above 0.1G) spinning at a 12m structure. It's a lot simpler mass-wise and technology-wise to just have your spacecraft split in two (the propulsion unit on the one end and the hab on the other) with a km long tether (or long rigid structure) and spin it. Doesn't look like Odyssey in Space, but it does the job credibly.

http://galaxywire.net/wp-content/uploads/2009/04/nasa_mars_artificial_gravity_1989.jpg

Something just occurred to me when reading this post. With a spinning km long tether or rigid structure are you not facing some rather horrible side effects? Specifically spinning a structure like that in a magnetic field and generating electrical charges. Given the troubles that numerous tether systems have had in LEO and extrapolating the possible effects in transiting the Van Allan belts, not to mention possible effects from solar wind/solar magnetic fields for deep space missions, I wonder if this approach would actually be viable.
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Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #75 on: 01/18/2010 04:48 PM »
BTW, I don't think the Flexible Path (starting by visiting NEOs and Phobos) will be seen as a step backward. It's many orders of magnitude beyond the Moon, and I think people will think that's impressive. Only technically-minded people will know much about the difficulty and expense of landing in a gravity well.
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Offline JohnFornaro

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Re: What should the Flexible Path include?
« Reply #76 on: 01/18/2010 07:39 PM »
Just thought I'd post this as a connecting link:

http://forum.nasaspaceflight.com/index.php?topic=19892.0;all
Sometimes I just flat out don't get it.

Offline kttopdad

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Re: What should the Flexible Path include?
« Reply #77 on: 01/18/2010 07:51 PM »
A lot of words have hit this forum about the relative gravity wells of the planets/bodies in our system.  I ran across this and felt like sharing.  A picture is worth a thousand words...

http://xkcd.com/681/

Dean

Edit:  This site is occasionally blocked by workplace network admins because some of the content is adult in nature.  The author started XKCD as a physics grad student at MIT, and we all know the low humor displayed by grad students.  The author worked at NASA for a while, but left to work on XKCD full-time.  http://en.wikipedia.org/wiki/Xkcd
« Last Edit: 01/18/2010 08:03 PM by kttopdad »

Offline simonbp

Re: What should the Flexible Path include?
« Reply #78 on: 01/18/2010 10:54 PM »
Only technically-minded people will know much about the difficulty and expense of landing in a gravity well.

As well as the fantastic rewards. Any meteorite collection will give you NEO samples, only boots on the Moon will give you high-priority, known-context lunar samples. NEOs are great for stunts, not so useful scientifically.

Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #79 on: 01/18/2010 11:07 PM »
Only technically-minded people will know much about the difficulty and expense of landing in a gravity well.

As well as the fantastic rewards. Any meteorite collection will give you NEO samples, only boots on the Moon will give you high-priority, known-context lunar samples. NEOs are great for stunts, not so useful scientifically.

I agree with you.
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Offline jongoff

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Re: What should the Flexible Path include?
« Reply #80 on: 01/18/2010 11:15 PM »
Only technically-minded people will know much about the difficulty and expense of landing in a gravity well.

As well as the fantastic rewards. Any meteorite collection will give you NEO samples, only boots on the Moon will give you high-priority, known-context lunar samples. NEOs are great for stunts, not so useful scientifically.

A meteorite collection will give you an NEO sample statistically biased towards NEOs that have a composition capable of surviving atmospheric entry at 10km/s+ velocities.  Not necessarily a representative sample.

But to be honest, I'm not as interested in the science as crafting a NASA approach that enables and encourages more and more commercial involvement in space.  The PoR sucks for that, though some of the non-FP A-com options weren't too terrible.  Going to the moon in a bloated unsustainable way that leaves us no closer to commercial development really isn't worth the cost, even if the science was more interesting.

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Offline neilh

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Re: What should the Flexible Path include?
« Reply #81 on: 01/19/2010 12:48 AM »
Regarding the original question, I've been intrigued by the proto-Flexible Path (using only existing launch vehicles) described in the 2004 "Next Steps In Deep Space" report headed by Wesley Huntress, and was curious about what parts forum participants think would need to be reworked (please excuse overly terse summary):

http://iaaweb.org/iaa/Studies/nextsteps.pdf

* development ofcrew capsule for launch and reentry
* development of "Geospace Exploration Vehicle" (GEV) accommodating (and protecting from radiation) 3 people up to 50 days, which can be attached/detached to/from crew capsule and refueled, capable of reaching SEL2 (and presumably other lunar/solar lagrange points) or lunar orbit; on return, after crew capsule detaches and GEV can robotically aerobrake back into LEO, 6 km/s delta-v capability
* construct human-assembled telescope at SEL2
* development of Interplanetary Transfer Vehicle (ITV), accommodating crew of 5-7 for 6-12 months (NEO mission); assembled/fueled at SEL2 with crew transfered via GEV, 6-8 km/s delta-v capability
* use of ITV for first trip to NEO [IMHO, ITV seems kind of over-capable for this]
* in preparation for Phobos trip, unmanned vehicle (CTV) deposits cargo/supplies needed at Phobos prior to crew arrival
* upgraded ITV (3 year mission duration, 8 km/s delta-v capability) transports crew to Phobos
* in-situ resource utilization from NEOs/Phobos, i.e. propellant production
* for Mars descent, upgraded ITV rendezvous with CTV in Mars orbit to gather needed assets (including lander and propellant), surface habitat potentially placed beforehand, potentially making use of Martian ISRU

Here's the guiding principles from the report:
Quote
1.) Goal-driven: Include only those destinations that are scientifically and culturally
compelling and for which human capabilities are both suitable and beneficial.
2.) Separate cargo and crew: Maximize efficiency and crew safety by focusing
transportation tasks. Minimize crew flight time by off-loading heavy cargo and scientific
equipment onto dedicated cargo vehicles, sent in advance of the crew for rendezvous at
the destination.
3.) One major new development per destination: Establish a sequence of destinations and
missions such that only one major new capability is required for each step, coupled with
evolutionary progress in existing capabilities.
4.) Emphasize use of existing transportation tools: Require no fundamentally new and
expensive propulsion systems or launch vehicles. Rely instead on proven technologies
and on astronaut capabilities for in-space assembly and fueling of reusable systems.
« Last Edit: 01/19/2010 06:09 AM by neilh »
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Offline Robotbeat

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Re: What should the Flexible Path include?
« Reply #82 on: 01/19/2010 01:04 AM »
Wow, neilh, that sounds like a really good plan to me!
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