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



 
 
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  #1  
Old May 20th 19, 05:56 PM posted to sci.space.policy
[email protected]
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Posts: 649
Default NASA’s full Artemis plan revealed: 37 launches and a lunar outpost

"In the nearly two months since Vice President Mike Pence directed NASA to return
to the Moon by 2024, space agency engineers have been working to put together a
plan that leverages existing technology, large projects nearing completion, and
commercial rockets to bring this about.

Last week, an updated plan that demonstrated a human landing in 2024, annual
sorties to the lunar surface thereafter, and the beginning of a Moon base by 2028,
began circulating within the agency. A graphic, shown below, provides information
about each of the major launches needed to construct a small Lunar Gateway, stage
elements of a lunar lander there, fly crews to the Moon and back, and conduct
refueling missions.

This decade-long plan, which entails 37 launches of private and NASA rockets, as
well as a mix of robotic and human landers, culminates with a "Lunar Surface Asset
Deployment" in 2028, likely the beginning of a surface outpost for long-duration
crew stays. Developed by the agency's senior human spaceflight manager, Bill
Gerstenmaier, this plan is everything Pence asked for—an urgent human return, a
Moon base, a mix of existing and new contractors."

See:

https://arstechnica.com/science/2019...lunar-outpost/
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  #2  
Old May 20th 19, 09:50 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

wrote on Mon, 20 May 2019 09:56:58 -0700 (PDT):

"In the nearly two months since Vice President Mike Pence directed NASA to return
to the Moon by 2024, space agency engineers have been working to put together a
plan that leverages existing technology, large projects nearing completion, and
commercial rockets to bring this about.

Last week, an updated plan that demonstrated a human landing in 2024, annual
sorties to the lunar surface thereafter, and the beginning of a Moon base by 2028,
began circulating within the agency. A graphic, shown below, provides information
about each of the major launches needed to construct a small Lunar Gateway, stage
elements of a lunar lander there, fly crews to the Moon and back, and conduct
refueling missions.

This decade-long plan, which entails 37 launches of private and NASA rockets, as
well as a mix of robotic and human landers, culminates with a "Lunar Surface Asset
Deployment" in 2028, likely the beginning of a surface outpost for long-duration
crew stays. Developed by the agency's senior human spaceflight manager, Bill
Gerstenmaier, this plan is everything Pence asked foran urgent human return, a
Moon base, a mix of existing and new contractors."

See:

https://arstechnica.com/science/2019...lunar-outpost/


This 'plan' is DOA. Hell, I'm about as 'pro-space' as you can be and
*I* am against it. Take money from college grants, increase NASA's
budget by over 30%, give them unprecedented authority to 'reprogram'
money, and rely on a booster (SLS Block 1B) that has essentially had a
'stop work' put on it)? That's just not a realistic plan.

What does it cost insofar as budget increases if we kill SLS and
reprogram THAT money and build a plan without SLS?


--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney
  #3  
Old May 20th 19, 10:58 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Default NASA's full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Mon, 20 May 2019
15:30:31 -0400:

On 2019-05-20 12:56, wrote:
"In the nearly two months since Vice President Mike Pence directed NASA to return
to the Moon by 2024


Unless MASA is given unlimited budgets, could it do this by 2024?


First, nobody is asking for "unlimited budgets". Second, I'm not
convinced that THIS plan is executable even if they give them all the
money they think they need (around another $8 billion a year on top of
the $20 billion they currently get).


A while back, NASA signalled that it isn't opposed to commercial rockets
and mentioned Falcon Heavy. Could this be the perfect excuse to put SLS
out of its misery and redirect budgets towards building a moon lander
ASAP and launch using Falcon Heavy or some other commercial rocket?


Falcon Heavy just doesn't have the 'grunt' for the sort of mission
architecture that NASA has fixed on. In fact, SLS Block 1 is short by
around 10 tonnes of having enough power for these missions. Block 1B
is required and that's essentially under a 'stop work' until Block 1
is completed. Since SLS Block 1B was scheduled for 2024 BEFORE it was
stopped, I doubt it can be completed in time for a 2024 manned lunar
landing. Falcon Heavy comes in around another 10 tonnes under SLS
Block 1, so NASA's mission architecture requires something MUCH bigger
than Falcon Heavy (about twice the capability).

The only vehicles in any stage of development that could do the job
with NASA's architecture are SLS Block 1B and Block 2, Falcon Super
Heavy (BFR), New Armstrong, and Long March 9. The latter two are
still in the planning stages right now. Musk's plan with Falcon Super
Heavy and Starship doesn't need NASA's architecture, but does require
the completion of Starship Tanker as well as the crewed article. Super
Heavy as a booster in the NASA program could probably do the job, but
it's not really intended to ever be used that way.


Would NASA require a sequence of flights similar to those that
preeceeded Apollo 11? Or would it compress the testing into fewer
flighst? Combine 9 and 10 together and test the LEM in Earth orbit, and
eliminate 8 which was a sightseeing flight.


It's probably going to require something similar. And you're
mischaracterizing the purpose of Apollo 8.


If NASA insists on SLS, would it compress the testing to culminate onto
the pne flight to the moon on the last set of SSMEs they have left? Or
would this trigger the contract to actual build more of them instead of
just studying how to build new SSMEs ?


Where did you get that they only have a single set of SSMEs left? Last
I knew they had 16 engines and hadn't expended any, so they should
have four sets of engines on hand. As for building more, that's
already at least partially triggered, since they've procured all the
long lead time items to produce six engines.


In terms of a lunar lander, considering the time frame, is NASA's only
option to dust off the LEM plans and just update avionics? (Or even
build an emulator on an iPhone and have it run the original software).


No. Do you not follow any news at all? NASA just recently let
contracts to 11 different companies to study and, in some cases, build
prototypes of pieces of their lander architecture. Note that one of
those companies is Blue Origin, which says that its Blue Moon lander
will be ready to fly by 2024.


Or do current NASA safety rules eliminate the LEM due to lack of
shielding , lanck of redundancy etc etc ?


What eliminates the LEM is that you would have to totally rebuild an
industrial base to produce it. It's probably faster and cheaper to go
with a 'clean sheet' design that uses currently existing industry.


In terms of hypergolic engines, has efficiency changed much since the
last Apollo missions, (aka: mass of new lander would have to be as
limited as it was for Apollo missions) or have significant improvements
happened since then to allow far more mass (shielding etc) to be loaded
onto the lander?


It doesn't matter, since hypergolic engines aren't a requirement. Blue
Moon, for instance, uses LH2/LOX.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #4  
Old May 21st 19, 03:05 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default NASA's full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Mon, 20 May 2019
17:59:01 -0400:

On 2019-05-20 16:50, Fred J. McCall wrote:

This 'plan' is DOA. Hell, I'm about as 'pro-space' as you can be and
*I* am against it. Take money from college grants, increase NASA's
budget by over 30%, give them unprecedented authority to 'reprogram'
money, and rely on a booster (SLS Block 1B) that has essentially had a
'stop work' put on it)? That's just not a realistic plan.


Likly designed to burden Trump's succesor with either a big boondoggle
or the unpopular "we are cancelling the project to get back to the moon".


Don't look now but your Trump Derangement Syndrome is showing. Take
your lithium and don't post until morning.


Looking at NASA web site:

They have a page announcing pork to 11 companies to generate reports.
https://www.nasa.gov/press-release/n...lunar-landers/


You're funny. You start with squealing about how NASA must start
working to develop a lander. When you find they have, you whine about
'pork'.


"transfer element for the journey from the lunar Gateway to low-lunar
orbit, a descent element to carry them to the surface, and an ascent
element to return to them to the Gateway"


I am curious about the "transfer element". Wouldn't the descent element
get crew from "Gateway" to the lunar ground like the LEM did? Why need
2 components to get from orbit to ground ?


You understand that the Gateway isn't in an orbit around the Moon,
right? It's in a LaGrange halo orbit. You need a piece to get you
from CPA to the Moon in that orbit to a low orbit that goes over
someplace you want to land. Everything I see talks as if 'direct
ascent' back to the Gateway will be used by the Ascent Element and
that the Transfer Element will return separately, but I don't see why
that should necessarily be the case. It might make more sense to use
the Transfer Element to get from LLO back to Gateway. Which one makes
the most sense might change on a case by case basis.

All that said, I'm not a big fan of NASA's architecture for lunar and
deep space exploration. There's a payload penalty for going to the
Gateway first and then down to the Moon and back. It leads to a whole
bunch of complication for no gain. It's not permanently manned and
needs Orion docked to it to support crew. That means crew duration is
pretty much limited to Orion duration. It does allow reuse of the
Descent and Transfer Elements, but it seems like all the fuel for them
will have to be lifted from Earth in the near term.


--
"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
  #5  
Old May 21st 19, 03:53 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default NASA's full Artemis plan revealed: 37 launches and a lunar outpost

JF Mezei wrote on Mon, 20 May 2019
19:37:57 -0400:

On 2019-05-20 17:58, Fred J. McCall wrote:

First, nobody is asking for "unlimited budgets". Second, I'm not
convinced that THIS plan is executable even if they give them all the
money


That was the crux of my question. aka: when budget is not an issue, can
they do it ?


Then you need to ask what you want to know without trying to 'spin'
the question with your politics. Personally, I don't think they can
get all the pieces done and in place by 2024.

Falcon Heavy just doesn't have the 'grunt' for the sort of mission
architecture that NASA has fixed on.


Siome of the NASA pictures showed different components launched
separately. Doesn't that give Falcon Heavy (or even Falcon 9) a means
to get the "stack" in orbit before it goes to the moon with all the fuel
it needs?


Pieces have to be just pretty damned small to do it with Falcon Heavy.
Nothing over 10 tonnes.


For SpaceX it woudl essentially be practice runs for the various systems
such as refueling, docking in orbit etch that would allow BFR/BFS to
launch and then multiple BFR launches to fuel BFS.


One more time. Things that are different just are not the same.
Nothing done would be applicable to BFR/BFS.

In fact, SLS Block 1 is short by
around 10 tonnes of having enough power for these missions. Block 1B
is required and that's essentially under a 'stop work' until Block 1
is completed.


Does Block 1B translate to new/updated engines, or would they uprate the
existing leftover SSMEs? In the case of the 6 new SSMEs that are being
produced, those are block 1s?


Oh, good Lord! Do you ever bother to find out even the most trivially
available things before you hang your hat on some preposterous notion?
There is no 'uprating' of the RS-25s between SLS Blocks, so all your
arm flapping is moot. Here is the difference. To get from Block 1 to
Block 1B the Interim Upper Stage is replaced by the Exploration Upper
Stage. To get from that to Block 2 you replace the SRBs with
something called the 'Advanced Booster'. This is still in study.

Where did you get that they only have a single set of SSMEs left?


16 engines = 4 SLS flights. So I was saying wthere NASA could do 3 tests
and use the last set to go to the moon. Or whether they need more sets
to get from a "never flown" to "boots on the moon".


That's not what you originally said. So you agree that they have FOUR
sets of engines left and not the single one you originally claimed.
Under the plan to get people on the Moon by 2024 the third flight of
SLS in 2024 does that. So after you put people back on the Moon you
STILL have a set of engines to fly the 2025 mission with.


We know first flight is unmanned. So that leaves 2 test flights before
a final set of engines can do the mission to the moon.


Except that doesn't get you there by 2024.


So if NASA will absolutely need more engines to make 2024 deadline, ...


They won't. Stop flapping your arms.


... how
come those 11 contracts don't include the contract extension to build
more than 6 SSME? Unless, of course, NASA knows it won't use SLS and
will use commercial to get the job done.


Because they won't need any new engines until 2026.

No. Do you not follow any news at all? NASA just recently let
contracts to 11 different companies to study and, in some cases, build
prototypes of pieces of their lander architecture.


Studies and prototypes. Does that really leave enough time to build/test
the damned thing for 2024 moonshot?


You've got to start somewhere. That is the first step. Did you
notice the duration of those contracts? Six months.


I am curious on the process where the VP was given indications that 2024
was doiable, or whether he knows it isn't realistics, but political
considerations made him make Nasa starts that undoiable project knowing
it will fail during the opposition party,s tenure at White House.


You're 'curious', all right. Curiously retarded by your Trump
Derangement Syndrome.

What eliminates the LEM is that you would have to totally rebuild an
industrial base to produce it. It's probably faster and cheaper to go
with a 'clean sheet' design that uses currently existing industry.


Don't you have to do the same for any design since it is starting from
scratch? It isn't likie buying some off the shelf car and then souping
it up like the pimp mobile Austin Powers uses to travel back in time.


When you do a design you design to **** we already build and that you
can get manufactured. When you trot out a half century old design you
don't have that luxury. You have to both do a redesign AND engage to
get a bunch of old **** that's no longer part of the industrial base
spooled up.


Forgetting science fiction which inflences those making pretty 3D
designs for powerpoints shown to politicians, wasn't the LEM design
optimized very well for the mission? Wouldn't a similar mission not end
up designing something similar?


Nothing in that paragraph makes any sense, but let me provide your
answers. Easy to forget things that don't exist. No. No.


Knowing more about lunar surface, would the landing gear be very
different or pretty much the same?


Yes.

It doesn't matter, since hypergolic engines aren't a requirement. Blue
Moon, for instance, uses LH2/LOX.


I assume those would be kept in high pressure tanks since they have to
be kept days with wildly varying temperatures?


Assume what you like, but remember what it means.


--
"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
  #6  
Old May 21st 19, 11:42 AM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,969
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

In article ,
says...

On 2019-05-20 12:56,
wrote:
"In the nearly two months since Vice President Mike Pence directed NASA to return
to the Moon by 2024


Unless MASA is given unlimited budgets, could it do this by 2024?


Nope. I give this "plan" zero chance of achieving the Administration's
aspirational date.

A while back, NASA signalled that it isn't opposed to commercial rockets
and mentioned Falcon Heavy. Could this be the perfect excuse to put SLS
out of its misery and redirect budgets towards building a moon lander
ASAP and launch using Falcon Heavy or some other commercial rocket?


Nope. In order to have enough political support in the Congress, the
pork-lifter will be part of the plan. Note that each of its planned
launches are specifically (prominently, actually) shown in the graphic.

Would NASA require a sequence of flights similar to those that
preeceeded Apollo 11? Or would it compress the testing into fewer
flighst? Combine 9 and 10 together and test the LEM in Earth orbit, and
eliminate 8 which was a sightseeing flight.


The graphic shows all of the SLS/Orion flights on it including the
"test" flights. There are no more. There is no money nor the time for
more (if the 2024 date is to be believed).

If NASA insists on SLS, would it compress the testing to culminate onto
the pne flight to the moon on the last set of SSMEs they have left? Or
would this trigger the contract to actual build more of them instead of
just studying how to build new SSMEs ?


Congress insists on SLS. NASA obliges. We've already discussed new
build RS-25 engines. You can look that info up again if you'd like.

Same thing will happen for SRB segments too. It's not yet clear what
will happen when those run out. But Northrup Grumman Innovation Systems
has already designed composite wound casings of the same diameter for
their Omega launch vehicle, so it's likely they'll pitch them as a
replacement. So likely a new contract will go to them to test a five
segment SRB with composite wound casings. Because opening up something
like this to competition would not help with the time-line.

In terms of a lunar lander, considering the time frame, is NASA's only
option to dust off the LEM plans and just update avionics? (Or even
build an emulator on an iPhone and have it run the original software).


Did you even read the article? No, the LEM design won't be "dusted
off". It can't operate at sea level internal pressures, which is the
standard today. Its walls are horribly thin and would not have the
factor of safety required today. And most importantly, the suppliers
are all gone. So you'd have to re-certify everything anyway! So it
would be treated as a new design. So you gain nothing by starting
there.

In terms of hypergolic engines, has efficiency changed much since the
last Apollo missions, (aka: mass of new lander would have to be as
limited as it was for Apollo missions) or have significant improvements
happened since then to allow far more mass (shielding etc) to be loaded
onto the lander?


Nope. Physics is physics. Look at the engine in Orion. Look at where
it came from and where that engine came from. Then look at the specs of
each engine in its lineage and compare them.

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.
  #7  
Old May 22nd 19, 02:36 AM posted to sci.space.policy
Sylvia Else[_3_]
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Posts: 18
Default NASA’s full Artemis plan revealed: 37 launches and a lunar outpost

On 21/05/2019 2:56 am, wrote:
"In the nearly two months since Vice President Mike Pence directed NASA to return
to the Moon by 2024, space agency engineers have been working to put together a
plan that leverages existing technology, large projects nearing completion, and
commercial rockets to bring this about.

Last week, an updated plan that demonstrated a human landing in 2024, annual
sorties to the lunar surface thereafter, and the beginning of a Moon base by 2028,
began circulating within the agency. A graphic, shown below, provides information
about each of the major launches needed to construct a small Lunar Gateway, stage
elements of a lunar lander there, fly crews to the Moon and back, and conduct
refueling missions.

This decade-long plan, which entails 37 launches of private and NASA rockets, as
well as a mix of robotic and human landers, culminates with a "Lunar Surface Asset
Deployment" in 2028, likely the beginning of a surface outpost for long-duration
crew stays. Developed by the agency's senior human spaceflight manager, Bill
Gerstenmaier, this plan is everything Pence asked for—an urgent human return, a
Moon base, a mix of existing and new contractors."

See:

https://arstechnica.com/science/2019...lunar-outpost/


Plans are easy. They've been told they need to get back to the moon
quickly, so they've produced a plan to do so.

Doesn't mean it will happen, or even that the people at NASA think it
will happen.

It's a good way of telling contractors to increase their prices though.

Sylvia.
  #8  
Old May 22nd 19, 03:21 AM posted to sci.space.policy
Greg \(Strider\) Moore
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Posts: 661
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

"JF Mezei" wrote in message ...

On 2019-05-21 06:42, Jeff Findley wrote:

Nope. In order to have enough political support in the Congress, the
pork-lifter will be part of the plan. Note that each of its planned
launches are specifically (prominently, actually) shown in the graphic.


When I saw the graphic, I had i my mind the SLS "icon" as being generic
since I was thinking NASA was open to using commercial rockets to get
this done by 2024.

So the graphic shows they can land a man on moon by 2024 by using only 3
porklifter flights (12 of 16 engines). Also shows that each of the 3
components of the LEM will be sent to orbit separately (I guess this is
where the commercial launchers come into play) and I would assume much
of the testing will be done on flights that don't involve SLS.

The graphic shows all of the SLS/Orion flights on it including the
"test" flights. There are no more. There is no money nor the time for
more (if the 2024 date is to be believed).


But the graphics also show generic rockets lifting the 3 components of
the "LEM". So I have to assume that there would be some earth orbit
flights in the 2021-22-23-24 time frame to test the LEM prototypes. (not
sure if manned or not).

Does Orion have a hatch compatible with Dragon2/station ? If so, could
they send crews on Dragon2 to dock with the "LEM" in LEO for humans to
test the lander and then return to earth in a Dragon? (or Constellation).


Same thing will happen for SRB segments too. It's not yet clear what
will happen when those run out.


I was always under impression that only the engines were leftover
inventory from shuttle and limited in supply, and that the core stage
and SRBs were built new, based on designs for shuttle.


Did you even read the article? No, the LEM design won't be "dusted
off". It can't operate at sea level internal pressures, which is the
standard today.


Why would LEM-2 need to operate at 1ATM since it will never operate on
earth?


For the same reason ISS operates at 1 ATM. It makes some parts of the
operations easier.


Put blueprints on the RFP and suppliers able to build what is already
designed will bid and get contract. You save the years needed to design
something. The LEM's design was tested and went through all that
certification back in the 1960s.


Because the LM of the 60s isn't adequate for today's needs. Heck, even in
the 60s they were pushing the limits of what it could do for the J class
missions.

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #9  
Old May 22nd 19, 03:42 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 Tue, 21 May 2019
19:28:14 -0400:

On 2019-05-20 22:05, Fred J. McCall wrote:

You understand that the Gateway isn't in an orbit around the Moon,
right? It's in a LaGrange halo orbit.


Was not aware of that. I was under the impression it was in lunar orbit.


I've explained this before. You should have been aware.


How does one get to La Grange from earth orbit? Raise elliptical orbit
to have apogee at La Grange and when you reach this, you circularize
orbit with angular speed around the earth that matches the moon's
angular speed around earth ?

Or just shoot up vertically such that you decelerate to 0 at La Grange
alttude and let Moon pull you forward as it rotates around the earth to
give you a circular orbit (matching moon's rotation so that you remain
between moon and earth) ?


You're a bit confused. There are five LaGrange points, not just one.
You're apparently thinking of L1. The planned orbit is around L2,
which is beyond the Moon. To be specific, the planned orbit would be
what is called a Near Rectilinear Halo Orbit around L2 such that it
would pass very low over the Moon's North Pole, somewhat higher (and
slower) over the Moon's South Pole, then out beyond the Moon to 'halo'
around L2. Now, halo orbits tend to be unstable, so require constant
powered adjustment to maintain.

Here, read this, watch the video, and read the cited papers.

https://space.stackexchange.com/ques...ear-halo-orbit


If the lunar lander ends up traveling from surface to Gateway in "direct
ascent", would that one be straight up ? or also raising orbit?


It could be anything, depending on where on the Moon you land. The
'best' current target for exploration is the South Pole, where we
think there is a lot of water ice.


The direct Ascent makes sense if you have weekly flights from La Grange
to moon orbit, but landers stay on moon for a month. Once the transfer
shuttle has dropped the lander in moon orbit, it can return to La Grange
to pick another lander to deliver to a different moon orbit (so first
lander wouldn't be able to catch a ride on it).


I'm missing something in your thought process here because the
preceding doesn't make sense. The Gateway is going to make its fast
and low north to south orbital segment around the Moon about every six
days. The Transfer Element(s) are going to take Lander(s) from the
NRHO of the Gateway to a low circular orbit about the Moon. From
there the Lander Element separates and lands. The Transfer Element
can't really get back to the Gateway for six days. So let's say it
does that because we want the Lander Element to spend roughly a month
on the surface. So they refuel it, mate with a new Lander, and 6 days
later (12 from the first Lander) it repeats and deploys a second
Lander. Another 12 days later and it deploys a third Lander. This
time instead of returning to the Gateway, it waits around. The first
Lander is 24 days into its mission. Six days later (during the next
Gateway pass) the first Lander flies up and rendezvous with the
Transfer Element, which then transfers back to the Gateway. Repeat
the same schedule an it recovers the other two Landers. You only have
a problem if one Lander wants to stay down N days and another lander
wants to stay down N-12 days, because then you have two Landers trying
to return at the same time.

Keep in mind that Gateway isn't all that big so you're not going to
have dozens of Landers and Transfer Elements available.


But I have to wonder about Gateway.

You not only have to carry the cargo to Gateway, but also the weight of
the stage that gets you there. So if you need 10 trips to fuel a ship at
Gateway, you are also raising 10 stage 2 (and the fuel needed for that
stage 2 to de-orbit).

If you do this from LEO, you have much smaller role for stage2, and you
end up raising to La Grange altitude only the final fully
assembled/fueled ship.


Or you don't do that at all (remember, we're talking about L2 here),
which is why I said there was something like a 20% 'cargo penalty'
when you used the Gateway rather than going directly to the Moon.


Say Gateway is supplied by only the Shuttle and Shuttle is grounded for
2 years. How long before it starts to fall towards Earth or moon?
aka: are frequent thurster adjustments needed or can the object be left
inert at that location for very long time ?


Shuttle couldn't get to the Gateway orbit even if it was still flying.
Gateway is intended to get something like one resupply mission a year.

pretty much limited to Orion duration. It does allow reuse of the
Descent and Transfer Elements, but it seems like all the fuel for them
will have to be lifted from Earth in the near term.


Doesn't the lamnder fiunction like the LEM, by leaving the lander on the
moon and ascending back to Gateway with only an "upper stage"? Or are
the modular section pr NASA graphics expected to remain attached as one
unit ?


I mistyped. That should have read "Ascent and Transfer Elements".


And if there a compelling reason while the lander couldn't leave from
Gateway and drop down to surface?


Other than that you would need (and throw away) a much larger and more
capable Descent Element because now it needs the 'grunt' to get from
NRHO to LLO in addition to what it needs to get from LLO to the
surface.


By how much would the transfer vehicle reduce the mass of the lander
compared to a lander that has the bigger tanks to be able to make the
journey on its own ? Is this some hiuge difference, or is the difference
small enough that both concepts get investigated ?


How many million dollars do you have that you can give me to develop
this answer for you?


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #10  
Old May 22nd 19, 04:08 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 Tue, 21 May 2019
20:04:31 -0400:

On 2019-05-21 06:42, Jeff Findley wrote:

Nope. In order to have enough political support in the Congress, the
pork-lifter will be part of the plan. Note that each of its planned
launches are specifically (prominently, actually) shown in the graphic.


When I saw the graphic, I had i my mind the SLS "icon" as being generic
since I was thinking NASA was open to using commercial rockets to get
this done by 2024.


Then why did you think they had a different rocket "icon" for some of
the flights?


So the graphic shows they can land a man on moon by 2024 by using only 3
porklifter flights (12 of 16 engines).


I think I said that already.


Also shows that each of the 3
components of the LEM will be sent to orbit separately (I guess this is
where the commercial launchers come into play) and I would assume much
of the testing will be done on flights that don't involve SLS.


You can probably assume that all of the testing for Artemis 'elements'
will take place in LEO an not involve SLS.

The graphic shows all of the SLS/Orion flights on it including the
"test" flights. There are no more. There is no money nor the time for
more (if the 2024 date is to be believed).


But the graphics also show generic rockets lifting the 3 components of
the "LEM". So I have to assume that there would be some earth orbit
flights in the 2021-22-23-24 time frame to test the LEM prototypes. (not
sure if manned or not).


Probably some of each; manned and unmanned.


Does Orion have a hatch compatible with Dragon2/station ?


Yes. It has a NASA Standard Docking Adapter. Why is it that you
refuse to look up even the most trivial things for yourself?


If so, could
they send crews on Dragon2 to dock with the "LEM" in LEO for humans to
test the lander and then return to earth in a Dragon? (or Constellation).


What does what Orion has have to do with anything? Orion doesn't dock
to anything other than Gateway.

Same thing will happen for SRB segments too. It's not yet clear what
will happen when those run out.


I was always under impression that only the engines were leftover
inventory from shuttle and limited in supply, and that the core stage
and SRBs were built new, based on designs for shuttle.


I believe you're correct here. I think the original intent was to use
SRB segments that were identical to those used with the Shuttle, but I
think that intent changed.

Did you even read the article? No, the LEM design won't be "dusted
off". It can't operate at sea level internal pressures, which is the
standard today.


Why would LEM-2 need to operate at 1ATM since it will never operate on
earth?


Why does ISS need to operate at 1 atmosphere since it never operates
on Earth? Nevertheless, it does. Why does Crew Dragon need to
operate at 1 atmosphere since it never operates on Earth?
Nevertheless, it does. Why does Boeing's Starliner need to operate at
1 atmosphere since it never operates on Earth? Nevertheless, it does.

Its walls are horribly thin and would not have the
factor of safety required today.


So what magic has happened to allow a lunar lander to now have much
heavier structure t please NASA standards? At the end of the day, won't
they be working with the same limitations on mass/fuel for the lander?


No, they won't. In fact, as I explained to you earlier, there is no
requirement that a Lander even use hypergolic engines and Blue
Origin's lander does not.


I am sure NASA wanted more shielding for the Apollow ERA LEM, but when
engineers come back with "no can do, all we can afford in the mass
budget is aluminium foil walls", then NASA has to bend the rules,
doesn't it?

That is why I asked if engine efficiently had radically changed since
then to allow much heavier vehicle to land on moon.


You asked that question because you made the horrible mistake of
assuming that a Lander Element would use some sort of hypergolic fuel.


And most importantly, the suppliers
are all gone. So you'd have to re-certify everything anyway!


Put blueprints on the RFP and suppliers able to build what is already
designed will bid and get contract.


Except it doesn't work that way. Try to buy an Intel 80486 processor.
You can't. And that will apply to almost every part in the LEM
blueprints.


You save the years needed to design
something. The LEM's design was tested and went through all that
certification back in the 1960s.


But all your parts are going to be from new vendors using new assembly
lines. You're going to have to certify everything as if it was a
brand new vehicle.


--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney
 




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