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.
That is why they call it the "proving ground". It will eventually "evolve" into a Mars transportation system.
Quote from: alexterrell on 09/14/2018 08:51 amQuote from: woods170 on 09/14/2018 08:09 amQuote from: su27k on 09/14/2018 07:48 amIf you couldn't afford to use it, why do you build it in the first place?Because of this:Quote from: TripleSeven on 09/13/2018 03:18 pmthe point is to crank back up the NASA build machineThe 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.
Quote from: woods170 on 09/14/2018 08:09 amQuote from: su27k on 09/14/2018 07:48 amIf you couldn't afford to use it, why do you build it in the first place?Because of this:Quote from: TripleSeven on 09/13/2018 03:18 pmthe point is to crank back up the NASA build machineThe 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.
Quote from: su27k on 09/14/2018 07:48 amIf you couldn't afford to use it, why do you build it in the first place?Because of this:Quote from: TripleSeven on 09/13/2018 03:18 pmthe point is to crank back up the NASA build machineThe very same reason why SLS and Orion are (still) being built.
If you couldn't afford to use it, why do you build it in the first place?
the point is to crank back up the NASA build machine
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.
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.
Quote from: Khadgars on 09/15/2018 01:17 amI 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.
Quote from: MATTBLAK on 09/15/2018 09:53 amI 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?
Quote from: Lemurion on 09/15/2018 03:05 amIt 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.
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.
Staging in LLO is impossible with Orion. Which is one of reasons why they choose this orbit.
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.
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.
Quote from: speedevil on 09/15/2018 09:45 amIn 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. QuoteIf 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.QuoteIt 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.
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.
Yes, I know but my point was that the Gateway would still work with BFR or some other commercial rocket.
For instance, the U.S. Government is not asking for the private sector to participate in the conceptual design ...
The SLS and Orion will perform all of the major transportation tasks
which is why I think private sector support missions will be a simple contractor arrangements.
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?