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NASA’s full Artemis plan revealed: 37 launches and a lunar outpost



 
 
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  #51  
Old May 26th 19, 01:50 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,974
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

In article ,
says...

On 2019-05-25 18:13, Fred J. McCall wrote:

Well, there's that and there's the problem that if you combine
everything in LEO now you need an upper stage with enough grunt to get
the whole works to where it's going all at once. Sending little
pieces is easier.



So they are hoping to have pieces small enough to get to Gaweway with
standard Falcon 9 second stage?


More like Falcon Heavy, Delta IV Heavy (Vulcan), New Glenn, Ariane V,
Proton, H-II (H3), and etc. NASA is not going to limit the size of
components unnecessarily when there are many more options (both existing
and under development), especially when you consider the heavy lifting
that the international partners can provide.

If you need to build a new second stage to get the pieces to Gateway,
why not build 1 hefty one which you fuel from LEO and get everything in
one go?


If you use launch vehicles bigger than a Falcon 9, you just send
everything needed straight to Gateway. No LEO assembly required.

During ISS assembly, people here complained about the 53 inclination
"costing" many more Shuttle flights since cargo capacity was more
limited. If you need to ship separate stage II to Gateway to deliver
each component, don't you end up with same problem of extra mass being
carried and thus reducing payload?


That's what you get when you are "justifying" SLS to keep the Alabama
mafia happy. It's also what you get when you are "accelerating" the
schedule to keep Trump/Pence happy. You do everything you can to
minimize development of anything "new" that's not "needed".

Jeff
--
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These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
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  #52  
Old May 26th 19, 04:49 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default NASA's full Artemis plan revealed: 37 launches and a lunar outpost

David Spain wrote on Sat, 25 May 2019 09:27:56
-0400:


We'd be better served if NASA acted like an investment bank and Congress
gave it the funds necessary to buy the desired end goal with as little
micro-management as possible. That has not been the established paradigm
and is not evident in this work of fiction either.


I've said for decades that we'd all be better served if NASA operated
more like the NACA upon which it was originally modeled, as a
technology development agency that did experimental projects and
helped fund the same by industry.


--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney
  #53  
Old May 26th 19, 05:09 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Sat, 25 May 2019
19:39:13 -0400:

On 2019-05-25 18:13, Fred J. McCall wrote:

Well, there's that and there's the problem that if you combine
everything in LEO now you need an upper stage with enough grunt to get
the whole works to where it's going all at once. Sending little
pieces is easier.


So they are hoping to have pieces small enough to get to Gaweway with
standard Falcon 9 second stage?


No. Falcon 9 flown as expendable can get around 6 tonnes to TLI.
Lander Elements will likely mass more than that. Falcon Heavy flown
reusable has about the same capability, but if expended can manage
around 20 tonnes or so to TLI


If you need to build a new second stage to get the pieces to Gateway,
why not build 1 hefty one which you fuel from LEO and get everything in
one go?


Because that's more complicated and requires a tanker vehicle that's
capable of refueling it. In other words, YOUR way takes longer, costs
more, and is more expensive to operate. Perhaps NASA has a job for
you?


During ISS assembly, people here complained about the 53 inclination
"costing" many more Shuttle flights since cargo capacity was more
limited.


And rightly so, since the only reason to launch to that high an
inclination was because of Russian limitations.


If you need to ship separate stage II to Gateway to deliver
each component, don't you end up with same problem of extra mass being
carried and thus reducing payload?


No, you don't. What you get is the difference between "possible" and
"impossible". You don't ship "stage II" to Gateway. That stage gets
you to the point where you can insert into Gateway's orbit. When in
doubt, look at reality to check your logic. You could perhaps throw
it all direct once you have SLS Block 1B on a pair of launches at $850
million dollars or more per launch. Or you can launch pieces on
Falcon Heavy expendable at around $150 million per launch and use
three launches (less than half the cost of SLS) plus an SLS launch for
Orion. So by breaking things up you SAVE around half a billion
dollars.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #54  
Old May 27th 19, 03:53 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

Jeff Findley wrote on Sun, 26 May 2019
08:43:17 -0400:

In article ,
says...

Jeff Findley wrote on Sat, 25 May 2019
08:47:58 -0400:

In article ,
says...

On 2019-05-24 06:34, Jeff Findley wrote:

Because if you look at the damn picture of the proposed time-line that's
all over online, *none* of the stages of the lunar lander are launched
by SLS. They're *all* launched on *separate* commercial launch
vehicles.

Are the separate launches all going to "Gateway" to deliver their
hardware, or would there be LEO dockings involved before the combined
parts get to Gateway ?

Everything possible goes to Gateway in order to justify its existence.
The only exception would be uncrewed landers with surface instruments,
robotic rovers, or modules/supplies to be prepositioned on the surface
for longer term crewed missions.


Well, there's that and there's the problem that if you combine
everything in LEO now you need an upper stage with enough grunt to get
the whole works to where it's going all at once. Sending little
pieces is easier. That's one of the 'justifications' for doing a
Gateway is to give an 'assembly area' to send pieces too without
having to send them all at once.


NASA is trying its best not to need LEO refueling. But, if they ever
get to the point where they're reusing crewed lander ascent stages and
transfer stages (Gateway to LLO), they'll need to be doing similar
refueling at Gateway.


True, but the 'argument' there is that everyone is docked up to
Gateway and 'tended' in order to refuel.


Ultimately, we need in orbit refueling to perform missions that are
bigger than Gateway/lunar surface. Whether that first refueling happens
in LEO (likely with cryogenics) or at Gateway (likely with hypergolics),
it's got to happen sooner or later. One of those approaches gets us
ready to go to Mars while the other simply doesn't.

NASA is making all the wrong long term investments in order to justify
SLS/Orion to the greatest extent possible. So that means delaying the
development of refueling and descoping that development to hypergolics
instead of cryogenics. NASA is deliberately choosing a path which
delays any "exploration" beyond the moon.


I think folks going to Gateway will do what Blue Origin has done and
opt for LH2/LOX engines, so it will be cryo either way. It will be
large volume 'mild cryo' in LEO (Starship) or deep cryo (LH2/LOX) at
Gateway. The big 'delay' in exploration beyond the Moon is that I
think the NASA plan assume in situ fuel manufacturing on the Moon
before they go for deep space. Deep Space exploration vehicles would
fly to Gateway, refuel with lunar LH2 and LOX, and depart. This makes
some sense in that getting fuel up from the Moon is much 'cheaper'
energetically than boosting it up from Earth, but it impacts your Mars
infrastructure as well, since now your in situ fuel factory there has
to find ice and make LH2/LOX out of water rather than making LOX and
liquid methane out of the atmosphere.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #55  
Old May 27th 19, 05:09 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Sun, 26 May 2019
14:01:35 -0400:

On 2019-05-26 12:09, Fred J. McCall wrote:

Because that's more complicated and requires a tanker vehicle that's
capable of refueling it. In other words, YOUR way takes longer, costs
more, and is more expensive to operate. Perhaps NASA has a job for
you?


SpaceX already has the software for Dragon2 to dock to another ship.


You say this like you have a point. You don't.


SpaceX is already planning on-in-orbit refueling and originally set to
go to mars by 2024. Surely the refueling mechansims are already in
development?


You say this like you have a point. You don't.


Surely those mechanisms could be fitted/tested on Falcon based vehicles
before BFR/BFS are in service?


Gee, USAF already knows how to do in flight refueling of aircraft.
Boeing already knows how to build supersonic aircraft. Surely all
that stuff could be fitted/tested on Piper Cub based vehicles?


Also, if a Falcon Stage 2 were sent up with a large tank for itslef in
lieu of any payload. Could the actual payloads launched separately then
dock/attach to it and the bit-tanker Stage2 then act as the CDM to bring
all the hardware between LEO and Moon ?


Unlikely and I'm not going to go to the effort to do the math to prove
or disprove it. It's your loony idea. YOU prove whether it will work
or not.


Or is the extra fuel needed for LEO-Gateway trip with all the hardware
attached to it (lander, ascent, transfer) too much to be carried to LEO
by a Falcon Heavy in single launch?

Using a Stage 2 with big fuel tanks would eliminate the need for fuel
transfers.


OK, but even Falcon Heavy cannot get a second stage to LEO with more
than about 54 tonnes of fuel on board in lieu of cargo. So that's
what I've got to get from LEO out to Gateway. I have to take the dry
mass of the second stage (a little under 4 tonnes), the mass of the
Ascent and Descent Elements (if we assume something about the mass of
the old LEM that's around 15 tonnes, give or take; using NASA numbers
for something more modern with more people you get 24-28 tonnes), and
the mass of the Transfer Element (which NASA thinks comes in around
12-15 tonnes). So the total mass you need to get to the Gateway from
LEO comes in at around 40-45 tonnes with 54 tonnes of fuel on a stage
with an Isp of 348 seconds. Getting from LEO to L2 is around 3400 m/s
delta-v. The kludge vehicle can manage a little over 2900 m/s of
delta-v.

You can't get there the way you're proposing, even using a pair of
Falcon Heavy launches. If you assume you can fully fuel the Falcon
second stage, you can get a little under 4100 m/s and you can. But
you need a second stage that can 'dock' to your other assembled
components, that can be refueled on orbit (you need at least 80 tonnes
of propellant aboard), and a 'tanker stage' that can refuel it. You
need three Falcon Heavy launches to get all this up there. Easier and
cheaper to change no vehicles, load the three pieces on separate
Falcon Heavy, and make three Falcon Heavy launches.

Will you stop proposing stupid **** now?


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #56  
Old May 27th 19, 11:51 AM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 1,974
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

In article ,
says...
I think folks going to Gateway will do what Blue Origin has done and
opt for LH2/LOX engines, so it will be cryo either way. It will be
large volume 'mild cryo' in LEO (Starship) or deep cryo (LH2/LOX) at
Gateway.


True, but this depends on what lander parts NASA picks. HSF at NASA has
been risk averse since the Challenger disaster. That means they'll
likely pick lander parts that use hypergolic propellants. So Blue
Origin would be out. Starship is never going to be picked as part of
the lunar architecture because it will be seen as "high risk".

Plus NASA mandated a three stage lander. That screams hypergolics from
the start. Neither Blue Origin's Blue Moon lander nor Starship would
qualify in NASA HSF's mind.

The big 'delay' in exploration beyond the Moon is that I
think the NASA plan assume in situ fuel manufacturing on the Moon
before they go for deep space. Deep Space exploration vehicles would
fly to Gateway, refuel with lunar LH2 and LOX, and depart. This makes
some sense in that getting fuel up from the Moon is much 'cheaper'
energetically than boosting it up from Earth, but it impacts your Mars
infrastructure as well, since now your in situ fuel factory there has
to find ice and make LH2/LOX out of water rather than making LOX and
liquid methane out of the atmosphere.


I've heard the water to LH2/LOX argument before. I find it lacking.
Again, we're talking NASA here. The agency who signed off on solid
aluminum wheels for all of its Mars rovers. The wear and tear on those
is mind boggling. They're literally falling apart after what I would
consider to be a pathetic number of miles/km traveled.

And we expect NASA to mine water, on the moon (with its abrasive dust
environment), and turn it into LH2/LOX? I'll believe that when pigs
fly.

All the engineering competitions (mostly college level) I see to mine
lunar regolith have everyone starting from scratch. Because we all know
that no one on earth moves around dirt/rock or mines anything, right?

There are industries on earth that know how to do this and they aren't
run by aerospace engineers. Adapting earth equipment to do this on the
moon would be the most straightforward way to go. The problem with that
is this equipment is *heavy*. But there are reasons it's heavy!

At any rate, once you reduce launch costs to put a reasonable amount of
equipment on the moon to start production of LH2/LOX in quantity, you
need to compare the new, lower, cost of launching LH2/LOX (or better
yet, methane/LOX) from earth to that mined on the moon. If you take
into account all the money it's going to take to maintain that
(expensive) infrastructure on the moon to produce that propellant, I'm
not convinced that it's going to break even in terms of the economics in
the next 25 years or so.

I'm not arguing that we shouldn't invest in lunar water mining. I'm
just against putting it on the critical path to send people to Mars.
It's simply not needed if something like Starship/Super Booster works
out. It's quite simply a hell of a lot easier to refuel a
Starship/Super Booster on earth using methane/LOX (both super cheap on
earth) than it is to mine water on the moon.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #58  
Old May 27th 19, 03:53 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default NASA's full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Sun, 26 May 2019
23:45:14 -0400:

On 2019-05-26 22:44, Fred J. McCall wrote:

NASA is saying that they need something like $32 billion in additional
funding over the 2020-2024 timeframe. But the amount is really
irrelevant. What's relevant is that one of the houses of Congress is
controlled by Democrats and they would go out on the launch pad and
shoot down vehicles before they'd allow Trump to have this.


Trump has not included NASA in his reality show scripts because it is of
little interest to his audience/base. He doesn't tweet about it, doesn't
rant about it in press conferences and doesn't raise it during campaign
speeches.


And yet it is Trump who first set the 2024 date.


Since either passing or blockng would have no political value because it
won't generate any fireworks at the 1600 Pennsylvania studios, it is
much easier to just process the funding and get it approved quietly.
Politically, there is nothing to win on either side. But from the lobby
side, both political parties likely benefit from approving it.


How much crack did you smoke to get far enough from reality to arrive
at your preceding conclusions?


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine
  #59  
Old May 27th 19, 04:49 PM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

Jeff Findley wrote on Mon, 27 May 2019
06:51:00 -0400:

In article ,
says...
I think folks going to Gateway will do what Blue Origin has done and
opt for LH2/LOX engines, so it will be cryo either way. It will be
large volume 'mild cryo' in LEO (Starship) or deep cryo (LH2/LOX) at
Gateway.


True, but this depends on what lander parts NASA picks. HSF at NASA has
been risk averse since the Challenger disaster. That means they'll
likely pick lander parts that use hypergolic propellants.


Unlikely, since the stated goal is to shift to in situ fuel production
on the Moon and you aren't going to be making hypergolics down there.


So Blue
Origin would be out. Starship is never going to be picked as part of
the lunar architecture because it will be seen as "high risk".


I think it's quite likely that choosing LH2/LOX will be seen as a
feature for Blue Moon, not a bug. We've come a long way from the days
when we used to worry about being able to get a restart on a rocket
engine (which is one of the justifications for accepting the poorer
performance of hypergolics).


Plus NASA mandated a three stage lander. That screams hypergolics from
the start. Neither Blue Origin's Blue Moon lander nor Starship would
qualify in NASA HSF's mind.


Actually, no. The Transfer Element isn't part of the lander. The
Blue Moon lander is a Landing Element. Blue Origin doesn't seem to
think they'll have any problems adding a 7.6 tonne Ascent Element on
the cargo platform and the Blue Origin effort is pretty much EXACTLY
what NASA has asked for.

The big 'delay' in exploration beyond the Moon is that I
think the NASA plan assume in situ fuel manufacturing on the Moon
before they go for deep space. Deep Space exploration vehicles would
fly to Gateway, refuel with lunar LH2 and LOX, and depart. This makes
some sense in that getting fuel up from the Moon is much 'cheaper'
energetically than boosting it up from Earth, but it impacts your Mars
infrastructure as well, since now your in situ fuel factory there has
to find ice and make LH2/LOX out of water rather than making LOX and
liquid methane out of the atmosphere.


I've heard the water to LH2/LOX argument before. I find it lacking.


Well, if you're going to pick and choose which bits of reality you
accept you can arrive at any conclusion you like.


Again, we're talking NASA here. The agency who signed off on solid
aluminum wheels for all of its Mars rovers. The wear and tear on those
is mind boggling. They're literally falling apart after what I would
consider to be a pathetic number of miles/km traveled.


You say that as if it's somehow relevant. It's not. And what is the
design lifetime of these things supposed to be, again?


And we expect NASA to mine water, on the moon (with its abrasive dust
environment), and turn it into LH2/LOX? I'll believe that when pigs
fly.


No, I expect them to let some contract to have someone do it, just
like they're doing with landers and such. As I said, if you're going
to pick and choose which bits of reality you accept you can arrive at
any conclusion you like. Me, I'm going to go with what people have
said. You understand that one of the drivers behind the NRHO that
Gateway is in is ease of access to the Moon's south pole (where we
think the highest chance is of finding water), right?


All the engineering competitions (mostly college level) I see to mine
lunar regolith have everyone starting from scratch. Because we all know
that no one on earth moves around dirt/rock or mines anything, right?

There are industries on earth that know how to do this and they aren't
run by aerospace engineers. Adapting earth equipment to do this on the
moon would be the most straightforward way to go. The problem with that
is this equipment is *heavy*. But there are reasons it's heavy!

At any rate, once you reduce launch costs to put a reasonable amount of
equipment on the moon to start production of LH2/LOX in quantity, you
need to compare the new, lower, cost of launching LH2/LOX (or better
yet, methane/LOX) from earth to that mined on the moon. If you take
into account all the money it's going to take to maintain that
(expensive) infrastructure on the moon to produce that propellant, I'm
not convinced that it's going to break even in terms of the economics in
the next 25 years or so.


So Mars is right out, then, since in situ fuel production is so hard
and it's REQUIRED if you're going to do Mars?


I'm not arguing that we shouldn't invest in lunar water mining. I'm
just against putting it on the critical path to send people to Mars.
It's simply not needed if something like Starship/Super Booster works
out. It's quite simply a hell of a lot easier to refuel a
Starship/Super Booster on earth using methane/LOX (both super cheap on
earth) than it is to mine water on the moon.


I think I made that argument somewhere along the way. Mostly it's a
bad idea because it leaves you with Mars vehicles that are burning the
'wrong' fuel for in situ production on Mars. Yes, there's water
there, but going with LH2/LOX for Mars vehicles makes things harder.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #60  
Old May 28th 19, 12:03 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 1,974
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

In article ,
says...
At any rate, once you reduce launch costs to put a reasonable amount of
equipment on the moon to start production of LH2/LOX in quantity, you
need to compare the new, lower, cost of launching LH2/LOX (or better
yet, methane/LOX) from earth to that mined on the moon. If you take
into account all the money it's going to take to maintain that
(expensive) infrastructure on the moon to produce that propellant, I'm
not convinced that it's going to break even in terms of the economics in
the next 25 years or so.


So Mars is right out, then, since in situ fuel production is so hard
and it's REQUIRED if you're going to do Mars?


The difference is in the effort that the in-situ propellant production
requires. On Mars, you've got some filters and vacuum pumps to pull in
CO2 from the thin atmosphere and your gas processing equipment that can
be located inside the landing craft (protected from the elements).

On the moon, we don't really know what we'll need to produce water in
quantity. Some people think it will be as easy as scooping up some
loose surface material from the lunar south pole area and baking it so
that the volatiles (mostly water) come out. I think that's going to be
a lot harder than it seems since we have zero actual surface data on the
properties of said surface material that is "high" in water content.
Add in the abrasive nature of the lunar regolith and you have a recipe
for constant breakdowns of equipment exposed to that regolith.

IMHO, lunar in-situ LH2/LOX production will be at least an order of
magnitude harder (which means more expensive) than in-situ methane/LOX
production on Mars done with LH2 brought from earth. Bringing the LH2
from earth makes the initial process much easier for those first Mars
missions. Later missions can likely get their H2O from Mars as well,
but it's not strictly necessary, so this provides for one more stepping
stone on the path.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
 




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