Author Topic: NASA Exploration Roadmap: A return to the Moon’s surface documented  (Read 110786 times)

Offline MATTBLAK

  • Elite Veteran & 'J.A.F.A'
  • Senior Member
  • *****
  • Posts: 5362
  • 'Space Cadets' Let us; UNITE!! (crickets chirping)
  • New Zealand
  • Liked: 2239
  • Likes Given: 3883
The style of your reply proves our point somewhat: rich on details etc, but not connected with the real world to some degree. But you are correct that the Presidential & NASA Leadership want to do very little.

As for adding New Zealand in there, probably for my benefit; N.Z. wont be getting involved in anyone's space program - a population of only 4.5 million with tens of billions in Earthquake damage to fix has other priorities.
« Last Edit: 03/19/2013 08:09 am by MATTBLAK »
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
Block 1 + SLS, without DSH, and no SLS updates needed.  Is HLR feasible?  Yes.

Dubious.  Remember, all you've got is a system capable of putting...

... some stuff up there, when what is needed is a lot of stuff.

Not what I said.  I was referring to the fact that while SLS Block 1's LEO payload is quite large, its upper stage is too small to take full advantage of this fact.

Block 1 could easily heave an ICPS plus 60 tonnes of payload into LEO, but an ICPS is utterly incapable of getting 60 tonnes of payload anywhere near translunar departure velocity.

Quote
Quote from: 93143
So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO.  According to page 12, you can't do that...

Huh? 

In my world, the ICPS is designed to support this lunar mission when placed on top of the 70ton SLS.  If it is currently incapable of doing this, and it can't be changed since it is already designed and built, then clearly, in my world, there is little intention for mission accomplishment.  The lunar mission should not be held hostage by the current "model" of ICPS.

The Interim Cryogenic Propulsion Stage is just a 5-metre Delta IV upper stage with a slight hydrogen tank stretch, maybe a bit of structural strengthening and some avionics mods.  It's a quick-and-dirty hack.  The cost of the whole program including flight units is in the low nine figures; peanuts compared to a real new upper stage.

The real SLS upper stage is the CPS, which is an all-new stage capable of properly leveraging SLS' enormous LEO capability.  Take an SLS Block 1, stick a CPS on top instead of an ICPS, and you have an SLS Block 1B, which is eminently capable of supporting a manned lunar return even without propellant depots.

Quote
it's not the case that a monster SLS is likely to be cheaper than a "small" SLS which more than triples the throw weight of shuttle.

Ironically, it could well be.  The larger, more capable CPS should be a bit more expensive than the ICPS, but the advanced boosters are supposed to be significantly cheaper, and if they save enough money the whole stack could be cheaper.  It certainly wouldn't be 'monstrously' expensive, and it's not design bloat - it's just a question of optimizing the stack we've got.

It is my understanding that the boosters and the upper stage are the only components NASA currently seems to want to upgrade.  Upper stage first, boosters later.  The core stays the same.

Quote
Of course there would be more than one launch of a fully functioning 70ton capable SLS, with LEO assembly of the necessary pieces for a lunar landing.

"Of course"?  That doesn't follow at all.  If the only existing EDS is too small for a single launch, and lacks any real loiter capability, what does LEO assembly buy you?  You'd have to develop a new EDS anyway, and once you've done that, you can just slap it on top of SLS and you don't have a Block 1 any more.

Quote
Also, where does page 12 say that "youcan't do that"?  'Cause the "takeaway" is that there is a "sizeable solution space for a 2 stage lander", that exists within the "SLS Block 1+" capability.

Block 1+ is not Block 1.  Page 12 says that "No Block 1 solutions exist without SLS element to perform LOI".  In other words, the lander can't do it, which is what I said.
« Last Edit: 03/18/2013 10:15 pm by 93143 »

Online PahTo

  • Full Member
  • ****
  • Posts: 1698
  • Port Angeles
  • Liked: 271
  • Likes Given: 1194
I believe the core needs significant mods to accommodate advanced boosters (even SRBs) to support increased loads.  Certainly true for LRBs that lift from the bottom.  If the "Advanced Booster" competition is a true competition, that is.
That's why I think 1B is all we'll see as an upgrade path for a long long time (assuming SLS flies more than a couple of missions, if at all).


It is my understanding that the boosters and the upper stage are the only components NASA currently seems to want to upgrade.  Upper stage first, boosters later.  The core stays the same.

« Last Edit: 03/18/2013 10:17 pm by PahTo »

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
Block 1 + SLS, without DSH, and no SLS updates needed.  Is HLR feasible?  Yes.

Dubious.  Remember, all you've got is a system capable of putting...

... some stuff up there, when what is needed is a lot of stuff.

1) Not what I said.  I was referring to the fact that while SLS Block 1's LEO payload is quite large, its upper stage is too small to take full advantage of this fact.

2) Block 1 could easily heave an ICPS plus 60 tonnes of payload into LEO, but an ICPS is utterly incapable of getting 60 tonnes of payload anywhere near translunar departure velocity.

Quote
Quote from: 93143
So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO.  According to page 12, you can't do that...

Huh? 

In my world, the ICPS is designed to support this [Edoit: multi-launch, with LEO assembly] lunar mission when placed on top of the 70ton SLS.  If it is currently incapable of doing this, and it can't be changed since it is already designed and built, then clearly, in my world, there is little intention for mission accomplishment.  The lunar mission should not be held hostage by the current "model" of ICPS.

3) The Interim Cryogenic Propulsion Stage is just a 5-metre Delta IV upper stage with a slight hydrogen tank stretch, maybe a bit of structural strengthening and some avionics mods.  It's a quick-and-dirty hack.  The cost of the whole program including flight units is in the low nine figures; peanuts compared to a real new upper stage.

The real SLS upper stage is the CPS, which is an all-new stage capable of properly leveraging SLS' enormous LEO capability.  Take an SLS Block 1, stick a CPS on top instead of an ICPS, and you have an SLS Block 1B, which is eminently capable of supporting a manned lunar return even without propellant depots.

Quote
it's not the case that a monster SLS is likely to be cheaper than a "small" SLS which more than triples the throw weight of shuttle.

4) Ironically, it could well be.  The larger, more capable CPS should be a bit more expensive than the ICPS, but the advanced boosters are supposed to be significantly cheaper, and if they save enough money the whole stack could be cheaper.  It certainly wouldn't be 'monstrously' expensive, and it's not design bloat - it's just a question of optimizing the stack we've got.

It is my understanding that the boosters and the upper stage are the only components NASA currently seems to want to upgrade.  Upper stage first, boosters later.  The core stays the same.

Quote
Of course there would be more than one launch of a fully functioning 70ton capable SLS, with LEO assembly of the necessary pieces for a lunar landing.

5) "Of course"?  That doesn't follow at all.  If the only existing EDS is too small for a single launch, and lacks any real loiter capability, what does LEO assembly buy you?  You'd have to develop a new EDS anyway, and once you've done that, you can just slap it on top of SLS and you don't have a Block 1 any more.

Quote
Also, where does page 12 say that "you can't do that"?  'Cause the "takeaway" is that there is a "sizeable solution space for a 2 stage lander", that exists within the "SLS Block 1+" capability.

6) Block 1+ is not Block 1.  Page 12 says that "No Block 1 solutions exist without SLS element to perform LOI".  In other words, the lander can't do it, which is what I said.

1) I did tersely summarize your previous comment, and do understand your point.

Whatever acronym you want to call the upper stage is fine, but it should not be arbitrarily limited to a stage that cannot do the job.

2) An improperly designed ICPS would be as limited as you surmise.

3) My bad for improper grammatical use of the pre-existing term "ICPS", a device of limited functionality.  Perhaps it could be called J-ICPS -- John's ICPS; a cryogenic propulsion stage of demonstrated pragmatic utility.  If it has not already been designed, then it needs to be so designed.

What is needed is a "real" upper stage.  I have no idea why this work is not being done by the officials tasked with this job.

4) If the "low nine figures" is "peanuts compared to a real new upper stage", and this is seen as a financial problem preventing the design of a "real",  "new" upper stage, then how come a "capable CPS" should only be a "bit more expensive than the ICPS"?

When the same argument is used both for and against a position, one can begin to suspect kool-aid usage.

5) "Of course", in my view only, where there is LEO assembly of that which is needed for TLI and lunar landing.

6) I now realize, from a closer read of the powerpoint, that Block 1+ is an innovative new term which imparts confusion and not clarity.  Furthermore, I did not intend to discuss the lander.
Sometimes I just flat out don't get it.

Offline Robert Thompson

  • Full Member
  • ****
  • Posts: 1177
  • Liked: 101
  • Likes Given: 658
http://spaceref.com/news/viewsr.html?pid=43609
NLSI HQ Seminar Series - Ben Bussey: Characterizing Luna Incognita
Source: NASA Lunar Science Institute Posted Monday, March 18, 2013

Date/Time: Wednesday, March 27, 2013 9:00AM PST, 12:00 Noon EST, 16:00 UTC

TO JOIN USING A WEB BROWSER: The slides and audio/video for this meeting will be presented using Adobe Connect. To join the meeting, connect to: http://connect.arc.nasa.gov/nlsi_directors_seminar/

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
Whatever acronym you want to call the upper stage is fine, but it should not be arbitrarily limited to a stage that cannot do the job.

ICPS is NASA's term for the slightly-modified Delta stage they're using to give the first couple of SLS launches some minimal BEO capability before the CPS is ready.  I didn't invent it, and neither of us gets to redefine it.

Quote
If the "low nine figures" is "peanuts compared to a real new upper stage", and this is seen as a financial problem preventing the design of a "real",  "new" upper stage

It's not seen as any sort of problem.  The whole point is that it is easy and cheap enough to just slip it into the program without bogging everything down.

Quote
then how come a "capable CPS" should only be a "bit more expensive than the ICPS"?

There's a difference between development cost and operations cost.

A new large cryogenic upper stage of the technology level under consideration is ~$3-5B to develop; the exact size doesn't matter much.  As I understand it, new builds of such a stage would differ from new builds of a somewhat smaller stage mainly in engine costs, since the cost of the tankage (not to mention the electronics) isn't a strong function of size once the production equipment is set up.

Quote
"Of course", in my view only, where there is LEO assembly of that which is needed for TLI and lunar landing.

If you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).

You can't do LEO assembly of a BEO mission if there's no way to get the assembly out of LEO.
« Last Edit: 03/19/2013 06:07 am by 93143 »

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
If you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).

Of course, I'm not in charge.  If I were, I'd lay out a plan along these lines:

Launch a 70 ton SLS with capsule, SM and lander to LEO.  Launch a second 70 ton SLS with a fully loaded 70 ton EDS to LEO.  Dock the two, and send 'em up to the Moon.  That's 140 tons in LEO, more than one Saturn V could get to LEO.

Of course, payloads would be designed to fit the rocket [gasp], the destination would be proximate, and the duration would be only a month or so.

I get the impression that nobody here or at NASA will consider a 140 ton lunar mission performing TLI from LEO.  In principle.

I suppose there's not much profit in buiding an EDS, SM, a lander, and all.  Nor would there be any inspiration in getting started on work that should have been done years ago.
Sometimes I just flat out don't get it.

Offline HappyMartian

  • Senior Member
  • *****
  • Posts: 2713
  • Tap the Moon's water!
  • Asia
  • Liked: 16
  • Likes Given: 2
The style of your reply proves our point somewhat: rich on details etc, but not connected with the real world to some degree. But you are correct that the Presidential & NASA Leadership want to do very little.

As for adding New Zealand in there, probably for my benefit; N.Z. wont be getting involved in anyone's space program - a population of only 4.5 million with tens of billions in Earthquake damage to fix has other priorities.


MATTBLAK, I've done the real world for over sixty years and can recognize when NASA is going nowhere due to incompetent Presidential space leadership. As an old Democrat I am clearly qualified to be disappointed and call it as I see it.

"L.E.O. is a PRISON: its time for a JAILBREAK!!"  - MATTBLAK

You want America and its international space exploration partners to jump from one LEO prison into a new and far more expensive one in L2. You are criticizing me for pointing out that the President and NASA's L2 plan is costly, unneeded, and risk adding nonsense.

Since I'm a former prison guard and have years of work experience in jails and business, I'm also tired of the LEO prison and am trying my best to help humans get on the Moon and on Mars, and avoid wasting decades of costly twiddling our thumbs in an L2 prison.

You want a permanent human base BLEO? Then go directly to a polar region of the Moon and do propellant ISRU from a known Lunar ice deposit.

New Zealand folks will be on the Moon, and so will a lot of folks from other countries, as long as we don't accept the costly and foolish L2 space proposals of a President that doesn't want American astronauts on the Moon.

Edited for politeness.
« Last Edit: 03/21/2013 09:03 am by HappyMartian »
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

Offline woods170

  • IRAS fan
  • Senior Member
  • *****
  • Posts: 12096
  • IRAS fan
  • The Netherlands
  • Liked: 18201
  • Likes Given: 12162
<snipped everything>

Throwing in my 2 cents...

You seem to be accusing each other of "being out of touch with reality". And that is exactly what you both are: out of touch with reality. With the current state of affairs on the planet (regardless of them being economic, political or whatever) there will never be an L2 station, let alone a colony on the moon doing ISRU. You two having an argument over them subjects is an utter waste of effort. Not to mention it being a rather effective way to pollute this thread with yet another pointless back-and-forth.
« Last Edit: 03/19/2013 02:24 pm by woods170 »

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
No!  All three of you are out of touch with reality!

woops... gotta go...
Sometimes I just flat out don't get it.

Offline HappyMartian

  • Senior Member
  • *****
  • Posts: 2713
  • Tap the Moon's water!
  • Asia
  • Liked: 16
  • Likes Given: 2
<snipped everything>

Throwing in my 2 cents...

You seem to be accusing each other of "being out of touch with reality". And that is exactly what you both are: out of touch with reality. With the current state of affairs on the planet (regardless of them being economic, political or whatever) there will never be an L2 station, let alone a colony on the moon doing ISRU. You two having an argument over them subjects is an utter waste of effort. Not to mention it being a rather effective way to pollute this thread with yet another pointless back-and-forth.



Wrong. America is spending billions of scarce dollars on an Orion Lunar orbit spaceship and an SLS Moon rocket.

Maybe it is time for some of the folks in other countries to figure out what they can contribute to international Lunar polar missions and to quit making excuses for doing as little as possible.

Maybe sniping at how Congress has focused American tax money on BLEO efforts that use the SLS and Orion to do Lunar ISRU is simply rude. If one isn't willing to help, perhaps being quiet would be useful.

Europe, Japan, China, Russia, or India could just go out and build a Lunar Lander. Wouldn't that be useful in a few years?

Be useful.


 
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Never is a long time.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
If you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).

Of course, I'm not in charge.  If I were, I'd lay out a plan along these lines:

Launch a 70 ton SLS with capsule, SM and lander to LEO.  Launch a second 70 ton SLS with a fully loaded 70 ton EDS to LEO.  Dock the two, and send 'em up to the Moon.  That's 140 tons in LEO, more than one Saturn V could get to LEO.

You continue to be focused on the "70 ton[ne]" figure.  Besides the fact that it's at least 20 tonnes short of the thing's true LEO performance, you seem to be advocating building a large EDS without acknowledging that this advances the Block designation.

Block 1 with a large EDS is Block 1B.

The above is of course just a technicality, but it is relevant to understanding the Moon First presentation.  And I recognize that you prefer using notional payload over block designators, but as it happens the Block 1B CPS (unlike the early concepts) can be burned to reach orbit, leading to a higher maximum LEO payload - the Boeing presentation gives 118 tonnes, which is 130 tons...

DIRECT's EDS could also burn to reach orbit, making the J-246 a more capable launcher than the J-130.  And, incidentally, the JUS was too heavy to reach orbit full; it had to burn to make orbit.  This resulted in a TLI capability slightly larger than the full LEO payload of a J-130 despite the nonzero burnout mass of the JUS, enabling exactly the mission you describe, though not exactly the way you describe it...

Essentially, Block 1 = J-140SH + DHCUS, and Block 1B = J-244SH.

NASA could certainly do something like what you propose.  Just not with Block 1, by definition.
« Last Edit: 03/20/2013 07:34 am by 93143 »

Offline HappyMartian

  • Senior Member
  • *****
  • Posts: 2713
  • Tap the Moon's water!
  • Asia
  • Liked: 16
  • Likes Given: 2
"Second stage
Engines    1 LE-5B
Thrust    137 kN (30,798 lbf)
Specific impulse    447 sec
Burn time    534 seconds
Fuel    LOX/LH2"

From: H-IIA   Wikipedia
At: http://en.wikipedia.org/wiki/H-IIA



Ask Europe and Japan to build the CPS.

Ask Russia, China, and India to work together to build the Lander.

Say "Please! And smile politely."


See:

H-IIA Launch Vehicle
At: http://www.jaxa.jp/pr/brochure/pdf/01/rocket01.pdf
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

Offline MATTBLAK

  • Elite Veteran & 'J.A.F.A'
  • Senior Member
  • *****
  • Posts: 5362
  • 'Space Cadets' Let us; UNITE!! (crickets chirping)
  • New Zealand
  • Liked: 2239
  • Likes Given: 3883
<snipped everything>

Throwing in my 2 cents...

You seem to be accusing each other of "being out of touch with reality". And that is exactly what you both are: out of touch with reality. With the current state of affairs on the planet (regardless of them being economic, political or whatever) there will never be an L2 station, let alone a colony on the moon doing ISRU. You two having an argument over them subjects is an utter waste of effort. Not to mention it being a rather effective way to pollute this thread with yet another pointless back-and-forth.


I actually quite agree with the thrust of your post, Woods170 - And I'm feeling negative towards the prospects of 'The World's' manned space programs. If ISS didn't exist - say it didn't survive by that one vote I think it was about 20 years ago - then after a Shuttle accident, the U.S. probably would have grounded the fleet for good and there would be no Commercial Crew program because there would be no destination. The rest of the world's manned space programs would likely only be Russia and China dabbling in Mir-like space stations in perpetuity.

As for Happy Martian contending that 'I'm out of touch with the Real World'.... Very easy thing to say to anyone, my friend, when probably the only things we have in common are we breathe air, are males and have a strong interest in manned spaceflight. I'm 47 and have been following the U.S. Space Program for more than 40 years. I'm a published (barely) science fiction writer, been to KSC for two launches and have interviewed several Astronauts and Space Engineers (I call some of them friends now), I have no formal engineering or science qualifications, I wouldn't have the guts to be a Prison Officer and my current job? Running a Warehouse and driving a forklift truck. At my age in this mediocre country, its about all I can do.

 There.

You now know a lot more about me - I hope you're satisfied. I aint no Space Scientist, just a 'Space Cadet' and second-rate blogger.

And yes; Earth Orbit Is a Prison and it Is time for a jailbreak. And I believe I'm far more right than I'm ever wrong when I reply to or riposte you.

Now that everyone has had their 'fun', I'll move on for now, lest some moderator lock or heavily trim the thread.

Whoops; Gotta Go...

...On second thoughts; it's not funny when I say that, let alone the other guy.
« Last Edit: 03/20/2013 04:44 am by MATTBLAK »
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline MATTBLAK

  • Elite Veteran & 'J.A.F.A'
  • Senior Member
  • *****
  • Posts: 5362
  • 'Space Cadets' Let us; UNITE!! (crickets chirping)
  • New Zealand
  • Liked: 2239
  • Likes Given: 3883
"Second stage
Engines    1 LE-5B
Thrust    137 kN (30,798 lbf)
Specific impulse    447 sec
Burn time    534 seconds
Fuel    LOX/LH2"

From: H-IIA   Wikipedia
At: http://en.wikipedia.org/wiki/H-IIA



Ask Europe and Japan to build the CPS.

Ask Russia, China, and India to work together to build the Lander.

Say "Please! And smile politely."


See:

H-IIA Launch Vehicle
At: http://www.jaxa.jp/pr/brochure/pdf/01/rocket01.pdf

That could work!! (I agree because I've said similar elsewhere). America supplies the Heavy Lifter and the Orion 'Mothership' and an International Consortium - I vote Japan to lead - builds a Lunar Lander that be configured for crew or cargo.
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline KelvinZero

  • Senior Member
  • *****
  • Posts: 4286
  • Liked: 887
  • Likes Given: 201
<snipped everything>

Throwing in my 2 cents...

You seem to be accusing each other of "being out of touch with reality". And that is exactly what you both are: out of touch with reality. With the current state of affairs on the planet (regardless of them being economic, political or whatever) there will never be an L2 station, let alone a colony on the moon doing ISRU. You two having an argument over them subjects is an utter waste of effort. Not to mention it being a rather effective way to pollute this thread with yet another pointless back-and-forth.

Inserting one of my hobby horses:
We could have a colony on the moon doing ISRU for $80m a year (A robotic one).
This is based on an alleged spacex quote of $80m to land one ton, and the fact you don't need to pay for the payload, instead use it as an international prize for the best ten ISRU experiments/robotic base components under 100kg each year.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
A rover scratching at Lunar regolith is hardly a lunar colony...
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
If you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).

Of course, I'm not in charge.  If I were, I'd lay out a plan along these lines:

Launch a 70 ton SLS with capsule, SM and lander to LEO.  Launch a second 70 ton SLS with a fully loaded 70 ton EDS to LEO.  Dock the two, and send 'em up to the Moon.  That's 140 tons in LEO, more than one Saturn V could get to LEO.

You continue to be focused on the "70 ton[ne]" figure. 

Well yes, until they actually build something that flies.

Quote from: 93
Besides the fact that it's at least 20 tonnes short of the thing's true LEO performance, you seem to be advocating building a large EDS without acknowledging that this advances the Block designation.

Block 1 with a large EDS is Block 1B.

The above is of course just a technicality, but it is relevant to understanding the Moon First presentation.  And I recognize that you prefer using notional payload over block designators, but as it happens the Block 1B CPS (unlike the early concepts) can be burned to reach orbit, leading to a higher maximum LEO payload - the Boeing presentation gives 118 tonnes, which is 130 tons...

I do prefer using notional payload.  I have a good reason for doing that.  The various Block iterations are deliberately confusing the issue.  Here's today's example: Block 1+, which covers the timeframe between Block 1 and Block 1A, I suppose.  It literally could be anything. To reduce the point to absurdity:  Block 1+ covers a throw weight of 70 tons plus one ounce to 97 or so tons minus one ounce.  It's suitable for HLR.

Because Block 1+ could be "anything", how can there be any discussion or even any tentative conclusions about its suitability for a Human Lunar Return?

I continue to object to their intent to build the 130 ton LV first, before even proposing payloads and missions.  This "Early Return" powerpoint continues to up the throw weight ante to the point where, mark my words, it will be soon presented that any human lunar return will be impossible without 130 ton SLS.

There's another notional issue which I would also like to assume: that an LV, whether 70 or 130 tons will put that weight into a circular orbit not to exceed 200km at anywhere between 28.5 and 51.s degrees inclination.

But that can't be assumed either.  Now the EDS must be called upon to do the circularization burn. To me, this is ridiculous.  It starts sounding like a self fulfilling prophecy, with an absurd outcome:  To get three or four astros to ISS in Orion, you need to have a 130 ton SLS, and a partially filled, mostly ballasted EDS.

It is the temporal and spatial convenience of assembling the trans lunar, trans L-point, or trans martian stack in LEO that concerns me.

Every launch should be filled to capacity.

Quote from: 93
NASA could certainly do something like what you propose.  Just not with Block 1, by definition.

Bingo.

By definition.  They could, but they don't want to.

There is no physical principle which prohibits a comprehensive, multi-decadal lunar, lagrangian, or martian mission profile, using LEO assembly, and multiple launches of Block 1, the 70 ton (or tonne) version of the SLS.

They have no intention of reducing costs by having multiple launches; allowing ops costs to become routine, where the manufacturing could become engineered incrementally for performance; where international partners could have ready access to a known LV and its adaptor; where the launch pad could become more and more automated; and so forth and so on.

It's a jobs program of make work with a BFR every other year, starting in 2030, say, for the elite, not the development of a new economy, which is what mankind needs.

Quote from: MattBlack
...it's not funny when I say that, let alone the other guy.

Yes it is.  Remember, there are three types of people:  Those who can count, and those who have a sense of humor.
« Last Edit: 03/20/2013 01:50 pm by JohnFornaro »
Sometimes I just flat out don't get it.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3054
  • Liked: 312
  • Likes Given: 1
The various Block iterations are deliberately confusing the issue.  Here's today's example: Block 1+, which covers the timeframe between Block 1 and Block 1A, I suppose.

No:

Quote from: NASA
As updates to Block 1 are still in work, Block 1A will be referred to as Block 1+

So Block 1+ is actually Block 1A, probably the old configuration with advanced boosters and a small two-engine 70-tonne CPS.

The "updates are still in work" comment probably refers to Block 1B.  Interestingly, while Block 1B doesn't use advanced boosters, its four-engine CPS is larger and more powerful, giving it more TLI capability.

Quote
I continue to object to their intent to build the 130 ton LV first, before even proposing payloads and missions.

It seems to me that they do not have such intent.  Hence Block 1B, which is just the "70-ton" version with a usefully large EDS added.

Quote
Now the EDS must be called upon to do the circularization burn. To me, this is ridiculous.

Why?  It's not a big deal for the EDS and it simplifies the core.  Also, I think the more even delta-V split from having the EDS do a significant burn to reach orbit results in a larger TLI payload.  Certainly it does in the two-launch case you propose.

If you really want to put a large chunk of inert cargo in LEO, I'm sure a small, cheap solid or hypergolic kick stage could be rigged to either do the circ burn or deorbit the core.

Quote
It starts sounding like a self fulfilling prophecy, with an absurd outcome:  To get three or four astros to ISS in Orion, you need to have a 130 ton SLS, and a partially filled, mostly ballasted EDS.

Orion is plenty capable of doing a circ burn by itself, if it ever has to be sent to ISS on SLS (which hopefully it won't).

As for lunar missions with a reusable lander, where Orion heads to L2 alone, you could either send a pack of supplies and/or propellant with Orion, part-fill the CPS (the mismatch isn't as dramatic in this case as it is with your proposed ISS mission), or just extend the ICPS contract and rename it the Itty-bitty Cryogenic Propulsion Stage or something like that.  It's basically common with Delta IV, so there shouldn't be much extra cost.

Quote
Quote from: 93
NASA could certainly do something like what you propose.  Just not with Block 1, by definition.

Bingo.

By definition.  They could, but they don't want to.

There is no physical principle which prohibits a comprehensive, multi-decadal lunar, lagrangian, or martian mission profile, using LEO assembly, and multiple launches of Block 1, the 70 ton (or tonne) version of the SLS.

No, there isn't - but to get the stack out of LEO you then need a propulsive element that doesn't count as part of SLS.  An SEP tug.  A chainable hypergolic stage.  That sort of thing.

If you want a large cryo EDS, which I see no good reason to avoid, it will be counted towards block incrementation, and you won't (by definition) have a Block 1 any more.

Calm down and think.  NASA isn't defining out options.  They're defining options.  What you're doing is redefining the least capable configuration so it covers one of the options you happen to like but refuse to use NASA's name for, and then accusing NASA of ignoring the capability of the configuration you've redefined.

When you say "Block 1", you seem to mean "Block 1 plus EDS", which is what NASA calls "Block 1B".

...

I suppose you could make a case that a smaller and less capable in-space-only CPS shouldn't advance the block designation.  But from the documentation I've seen, it seems that the definition of Block 1 includes ICPS as the upper stage, even though it doesn't burn to reach orbit (except maybe a circ burn).  I don't think you'll have much luck with that one...
« Last Edit: 03/20/2013 08:35 pm by 93143 »

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1