Author Topic: NASA updates Lunar Gateway plans  (Read 49537 times)

Offline freddo411

  • Full Member
  • ****
  • Posts: 1052
  • Liked: 1197
  • Likes Given: 3417
Re: NASA updates Lunar Gateway plans
« Reply #60 on: 09/15/2018 03:13 am »
I find it astounding the way the comments continue to be on here.  I understand that most everyone is beyond cynical at this point, and for some good reasons for sure.  But listening to everyone state that what is essentially a mini ISS in lunar orbit that involves multiple space agencies has zero value?  I don't get it, even if you are not for government funded launch vehicles.



Perhaps an analogy would be useful here.   

Imagine the Army corp of Engineers needs a project in order to stay gainfully employed.   So a mysterious process occurs where the it is decided that they should go to the geographic center of Kansas and build a giant, 5 billion dollar earthen wall 900 meters high by 10 km long -- the largest dam ever constructed ... except it is not actually holding back a river.

This is the most fantastic project ever!  It is the biggest!   It takes a great deal of work by talented engineers and builders from all 50 US states.   It is a marvel of engineering.

Is this wise?

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8862
  • I live... along the coast
  • Liked: 10199
  • Likes Given: 11933
Re: NASA updates Lunar Gateway plans
« Reply #61 on: 09/15/2018 04:18 am »
That is why they call it the "proving ground". It will eventually "evolve" into a Mars transportation system.

I think that there are many that don't see how the Lunar Gateway is a direct "proving ground" for going to Mars.

Sure, it's going to be a human habitat that is beyond LEO, but it's not meant for long-term occupation - which is probably the single most important attribute to be developed and tested for long-duration trips to places like Mars.

The Lunar Gateway would certainly be a progression from our LEO efforts. But at what cost? And while NASA talks about Public/Private Partnerships (PPP), which are laudable, PPP's require a business case for the private partners, and it's not clear what that business case is.

For instance, neither of the current PPP's, the Commercial Cargo and Commercial Crew programs, have been able to attract non-NASA business. So I would not be surprised if the private sector would be leery/cautious about assuming there would be a business case for investing their own money in a Lunar Gateway.

But a Lunar Gateway effort could just use the private sector in a straight contractor capacity, which is fine, but that should be delineated in the cost analysis for the Lunar Gateway. And, BTW, such a cost analysis has not been given to Congress, much less the public. So we don't know how this Lunar Gateway would compare to our current space station, the ISS - which is important, since the cost of the ISS is something that is debated as to whether it's worth the taxpayer money, so one would think knowing the cost of the Lunar Gateway would be important as a comparison.

It is clear that NASA has more to do on the proposal for the Lunar Gateway, so maybe the above questions will be addressed. More information would be helpful...
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Prettz

  • Full Member
  • ****
  • Posts: 497
  • O'Neillian
  • Atlanta, GA
  • Liked: 259
  • Likes Given: 30
Re: NASA updates Lunar Gateway plans
« Reply #62 on: 09/15/2018 04:30 am »
If you couldn't afford to use it, why do you build it in the first place?

Because of this:

the point is to crank back up the NASA build machine

The very same reason why SLS and Orion are (still) being built.
... and that is the reason why the benefit of these projects is questionable. NASA builds then so that NASA can build them.

That is why they call it the "proving ground". It will eventually "evolve" into a Mars transportation system.
Solar-electric propulsion has no role to play in manned missions to Mars.

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
Re: NASA updates Lunar Gateway plans
« Reply #63 on: 09/15/2018 04:49 am »
It would be useful to send 'cargo containers' or chemical propulsion modules (Earth return?) to Martian orbit. Or indeed, most anything you want. It all depends on one's chosen mission architecture.
"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
Re: NASA updates Lunar Gateway plans
« Reply #64 on: 09/15/2018 04:55 am »
I'm beginning to think the LOP-G overall is a $20 billion dollar waste of time and money. You could build a pretty good Lander for that kind of money - or at least get most of the way to one. Unless the facility was a dedicated Propellant Depot for a truly reusable Lunar Lander; and it would have to be in the best orbit possible for delta-vee benefits (L-1?). I would recommend L-1 because if a lunar farside radio astronomy rig is set up, a station constantly at L-2 could undermine the research.
« Last Edit: 09/15/2018 05:00 am by MATTBLAK »
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline speedevil

  • Senior Member
  • *****
  • Posts: 4406
  • Fife
  • Liked: 2762
  • Likes Given: 3369
Re: NASA updates Lunar Gateway plans
« Reply #65 on: 09/15/2018 09:45 am »
It would be useful to send 'cargo containers' or chemical propulsion modules (Earth return?) to Martian orbit. Or indeed, most anything you want. It all depends on one's chosen mission architecture.
For a fully developed LOPG to be cheaper to do some mission architectures, and for that to be a valid justification for it implies some things that it seems a large stretch to be true.

In order for it to be useful to do that, you need to get the component to LOPG, which is most of the delta-v to Mars.
Once you add on the required Argon or whatever to get the tug to and back from Mars insertion, the total mass may well not have gone down, and additional requirements may have been added on to make it safe to approach LOPG.
If you're using the ion tug to bring it from earth, it is unclear why you'd move it through LOPG.

If you are sending (say) 100 tons total to Mars using a (by that time) $30B resource, and using as a primary justification that you've halved the cost of doing so (which may be true, for some sorts of launchers), you are implicitly valuing your cargo at some 600M/ton, and assuming that it is utterly impossible to do it cheaper.

I note that FH can launch stuff direct to Mars for of the order of $10M/ton, without any optimisation, so the above justification also implies that it is impossible to shrink cost of stuff going to Mars (not cost of launch) to much below $600M/ton.

It also implies wholesale failure of the efforts to get reusability working, and assumes that they have been delayed for more than a decade, and that assembly in orbit - even for docking - remains impossible for that decade, even in the face of a $30B investment as an alternative in those technologies.



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
Re: NASA updates Lunar Gateway plans
« Reply #66 on: 09/15/2018 09:53 am »
I did say 'depending on one's chosen mission architecture'. I was not explicitly advocating SEP cargo tugs. A combined chemical/SEP approach - under certain circumstances - could be a really efficient way to do things.
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline speedevil

  • Senior Member
  • *****
  • Posts: 4406
  • Fife
  • Liked: 2762
  • Likes Given: 3369
Re: NASA updates Lunar Gateway plans
« Reply #67 on: 09/15/2018 10:06 am »
I did say 'depending on one's chosen mission architecture'. I was not explicitly advocating SEP cargo tugs. A combined chemical/SEP approach - under certain circumstances - could be a really efficient way to do things.

'Depending on one's chosen mission architecture' implies there is one mission architecture at least for which LOPG plays a key role.

Can you point to one?

Offline TrevorMonty

Re: NASA updates Lunar Gateway plans
« Reply #68 on: 09/15/2018 11:00 am »
I find it astounding the way the comments continue to be on here.  I understand that most everyone is beyond cynical at this point, and for some good reasons for sure.  But listening to everyone state that what is essentially a mini ISS in lunar orbit that involves multiple space agencies has zero value?  I don't get it, even if you are not for government funded launch vehicles.



I think the problem with the Gateway is that while it may offer certain benefits, it has enough drawbacks that offset its benefits that it may well end up with a net zero value.

It makes a return to the Moon objectively harder by increasing the delta-V requirements, and the argument has been made that it will take up enough of NASA's HSF budget that the agency won't really be able to afford to do anything else of any significance during its lifetime.
How does it increase DV to moon surface.?

 Staging in LLO is impossible with Orion.
Which is one of reasons why they choose this orbit.

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
Re: NASA updates Lunar Gateway plans
« Reply #69 on: 09/15/2018 11:06 am »
I did say 'depending on one's chosen mission architecture'. I was not explicitly advocating SEP cargo tugs. A combined chemical/SEP approach - under certain circumstances - could be a really efficient way to do things.

'Depending on one's chosen mission architecture' implies there is one mission architecture at least for which LOPG plays a key role.

Can you point to one?
No - there have just been notional discussions here and elsewhere. I've seen a Boeing PowerPoint somewhere that was around before LOP-G and the 'Deep Space Gateway'. Solar SEP ideas have been around since the asteroid retrieval concept and before that, too.
« Last Edit: 09/15/2018 11:09 am by MATTBLAK »
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline speedevil

  • Senior Member
  • *****
  • Posts: 4406
  • Fife
  • Liked: 2762
  • Likes Given: 3369
Re: NASA updates Lunar Gateway plans
« Reply #70 on: 09/15/2018 11:17 am »
It makes a return to the Moon objectively harder by increasing the delta-V requirements, and the argument has been made that it will take up enough of NASA's HSF budget that the agency won't really be able to afford to do anything else of any significance during its lifetime.
How does it increase DV to moon surface.?

Staging in LLO is impossible with Orion.
Which is one of reasons why they choose this orbit.
That is only a justification for a program if all similar capability vehicles that might be purchased with equivalent funding share this limitation.
This is at least very arguable.

I think it also implicitly assumes that SLS with the EUS is delayed for the forseeable future, as with the EUS, Orion can get to LLO. (rough numbers I have not verified)

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39215
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32735
  • Likes Given: 8178
Re: NASA updates Lunar Gateway plans
« Reply #71 on: 09/15/2018 11:38 am »
Staging in LLO is impossible with Orion. Which is one of reasons why they choose this orbit.

Staging in LLO is possible with Orion, provided that the EUS can last the three days to the Moon and perform LOI. Orion then has enough delta-V to leave LLO on its own.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline pathfinder_01

  • Senior Member
  • *****
  • Posts: 2074
  • Liked: 271
  • Likes Given: 8
Re: NASA updates Lunar Gateway plans
« Reply #72 on: 09/15/2018 04:34 pm »

In order for it to be useful to do that, you need to get the component to LOPG, which is most of the delta-v to Mars.
Once you add on the required Argon or whatever to get the tug to and back from Mars insertion, the total mass may well not have gone down, and additional requirements may have been added on to make it safe to approach LOPG.

The way it would work is that you would use an chemical rocket to escape earth orbit and SEP to speed the trip to Mars then use chemical again to get into orbit around Mars and use SEP or Chemical to return to Earth parking in an high earth orbit for reuse. The SEP would tend to shrink the total mass of the mission as most of the mass of an mars mission is propellant and you are departing from a high orbit. However I would agree that LOPG is not needed for this as the ship could be assembled anywhere and does not need LOPG for assembly. In fact many plans call for using SEP to push a craft into high Earth orbit from LEO( negating the need for SLS) and LOPG if assembled elsewhere could put built by currently operational rockets then moved to it's location.


Quote
If you're using the ion tug to bring it from earth, it is unclear why you'd move it through LOPG.

Reminds me of one of the selling points of the ISS that spacecraft could be assembled there for missions to the Moon or Mars and once the ISS is built, protecting the microgravity trumped that use.  Color me doubtful that NASA will build anything more after it gets LOP-G for budget reasons.



Quote
It also implies wholesale failure of the efforts to get reusability working, and assumes that they have been delayed for more than a decade, and that assembly in orbit - even for docking - remains impossible for that decade, even in the face of a $30B investment as an alternative in those technologies.

Nah it simply is a make work project for SLS/Orion. I like the SEP part but everything else is doubtful. SEP could reduce the cost of going to Mars under the right conditions but as currently presented I fear that LOPG will be more an hindrance than an help.

Offline TrevorMonty

Re: NASA updates Lunar Gateway plans
« Reply #73 on: 09/15/2018 08:21 pm »

In order for it to be useful to do that, you need to get the component to LOPG, which is most of the delta-v to Mars.
Once you add on the required Argon or whatever to get the tug to and back from Mars insertion, the total mass may well not have gone down, and additional requirements may have been added on to make it safe to approach LOPG.

The way it would work is that you would use an chemical rocket to escape earth orbit and SEP to speed the trip to Mars then use chemical again to get into orbit around Mars and use SEP or Chemical to return to Earth parking in an high earth orbit for reuse. The SEP would tend to shrink the total mass of the mission as most of the mass of an mars mission is propellant and you are departing from a high orbit. However I would agree that LOPG is not needed for this as the ship could be assembled anywhere and does not need LOPG for assembly. In fact many plans call for using SEP to push a craft into high Earth orbit from LEO( negating the need for SLS) and LOPG if assembled elsewhere could put built by currently operational rockets then moved to it's location.


Quote
If you're using the ion tug to bring it from earth, it is unclear why you'd move it through LOPG.

Reminds me of one of the selling points of the ISS that spacecraft could be assembled there for missions to the Moon or Mars and once the ISS is built, protecting the microgravity trumped that use.  Color me doubtful that NASA will build anything more after it gets LOP-G for budget reasons.



Quote
It also implies wholesale failure of the efforts to get reusability working, and assumes that they have been delayed for more than a decade, and that assembly in orbit - even for docking - remains impossible for that decade, even in the face of a $30B investment as an alternative in those technologies.

Nah it simply is a make work project for SLS/Orion. I like the SEP part but everything else is doubtful. SEP could reduce the cost of going to Mars under the right conditions but as currently presented I fear that LOPG will be more an hindrance than an help.
There is no public plans by NASA to enable EUS to do this.

There is also issue with Orion radiators not supporting LLO operations. See page 19-20 from this report.

http://fiso.spiritastro.net/telecon/Whitley_4-13-16/

The current long term plan is mining polar water for fuel, hence choice of NRO. With surface refuelling landers only need a DV of 2.7km/s, then staging at EML1 or NRO is better option. As this reduces DV requirements of LEO-NRO trip.



Offline yg1968

  • Senior Member
  • *****
  • Posts: 17267
  • Liked: 7123
  • Likes Given: 3065
Re: NASA updates Lunar Gateway plans
« Reply #74 on: 09/17/2018 02:51 pm »
To me Gateway is exactly what NASA should be doing. NASA can leave transportation to commercial companies but building space infrastructure such as Gateway is still needed.

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8862
  • I live... along the coast
  • Liked: 10199
  • Likes Given: 11933
Re: NASA updates Lunar Gateway plans
« Reply #75 on: 09/17/2018 11:12 pm »
To me Gateway is exactly what NASA should be doing. NASA can leave transportation to commercial companies but building space infrastructure such as Gateway is still needed.

With the Lunar Gateway NASA is still in the space transportation business - how do you think the crew get to/from the Lunar Gateway? The NASA SLS and Orion.

And building space infrastructure is also a transportation task, which is also being done by the SLS.

Taking that into account commercial companies don't really have much to do other than deliver some occasional cargo.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline yg1968

  • Senior Member
  • *****
  • Posts: 17267
  • Liked: 7123
  • Likes Given: 3065
Re: NASA updates Lunar Gateway plans
« Reply #76 on: 09/18/2018 02:39 am »
Yes, I know but my point was that the Gateway would still work with BFR or some other commercial rocket.
« Last Edit: 09/18/2018 02:40 am by yg1968 »

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1809
  • Likes Given: 1302
Re: NASA updates Lunar Gateway plans
« Reply #77 on: 09/18/2018 02:54 am »
Yes, I know but my point was that the Gateway would still work with BFR or some other commercial rocket.

In theory insert some electric propulsion modules in place of the "after cargo" modules in the BFR. Then you can have an orbiting BFS in any Lunar orbit you wanted by about 2024 if the SpaceX schedule holds for the cost of booking a few BFR flights and leasing a BFS.  ;D

It appears that the current LOP-G (Gateway) concept is superseded by current events at Hawthorne.

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8862
  • I live... along the coast
  • Liked: 10199
  • Likes Given: 11933
Re: NASA updates Lunar Gateway plans
« Reply #78 on: 09/18/2018 03:02 am »
Yes, I know but my point was that the Gateway would still work with BFR or some other commercial rocket.

Why would you need the Lunar Gateway if the BFS can take you to the surface of the Moon for far less than the SLS/Orion?

As of today the U.S. Government is hoping that the private sector will be willing to partner with NASA on the Lunar Gateway, but in reality there really isn't much that the private sector can partner on.

For instance, the U.S. Government is not asking for the private sector to participate in the conceptual design and what the goals will be (i.e. their needs) - those have already been decided. The SLS and Orion will perform all of the major transportation tasks, and what is left is unlikely to lead to an opportunity that the private sector will want to spend their own money on, which is why I think private sector support missions will be a simple contractor arrangements.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline ncb1397

  • Senior Member
  • *****
  • Posts: 3497
  • Liked: 2310
  • Likes Given: 29
Re: NASA updates Lunar Gateway plans
« Reply #79 on: 09/18/2018 04:43 am »

For instance, the U.S. Government is not asking for the private sector to participate in the conceptual design ...

There is more than one private sector company out there. See attachment.

Quote
The SLS and Orion will perform all of the major transportation tasks

20% of construction flights are currently slated for a launch vehicle other than SLS. If there was an alternative vehicle, that percentage might change. Cargo flights are slated to go on other launchers than SLS, with the caveat if there is extra performance on SLS crew flights, it will be used. 100% of crew flights are slated to go on SLS, but that percentage could change if there is an alternative vehicle (which there isn't currently).

Quote
which is why I think private sector support missions will be a simple contractor arrangements.

So?

Quote
Why would you need the Lunar Gateway if the BFS can take you to the surface of the Moon for far less than the SLS/Orion?

1.) BFS can't do anything currently. The farthest it has is a few hundred feet off of a barge
2.) NASA is developing electric propulsion systems that BFS doesn't satisfy. Travel times would be on the order of 2 months to 15 months to Mars, which, on the high performance end is far superior to anything BFS is capable of and requires far less IMLEO (like 150 tons for a single ship). If the government hadn't supported chemical rockets 50 years ago, it is entirely possible that they wouldn't have progressed to the point currently where BFR was acheivable.
« Last Edit: 09/18/2018 04:47 am by ncb1397 »

Tags:
 

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