Total Members Voted: 102
Voting closed: 02/12/2016 08:01 pm
That part of ISS was highly successful. It's too bad we didn't do more such aid for post-Soviet Russia in the 1990s, we may not have a tyrant in power there and geopolitical frictions like we have today. There really needed to be a post-Cold-War Marshall Plan. (And you could say the same thing about the Rust Belt and Appalachia, especially after the 2008 recession.) Anyway.
Quote from: ncb1397 on 12/28/2016 09:04 pmQuote from: Oli on 12/25/2016 09:56 pmQuote from: ncb1397 on 12/24/2016 05:46 pmJust to flesh out ideas on how Moon and Mars don't have to be in conflict with each other. And you can do both using assets and technology that NASA already has or is over half-way through the development pipeline.1.5MW is not sufficient for crew transfer given that kind of mass. Or what are the SEP specs?These were the specs that I was working off of:fuel - 35,000 kg Xenonsolar power - 1500 MW @ 1 AUengine power - 1375 MWengine thrust - 23 Nisp - ~9500 secondsMars- ~50% powerEarth- 100% powerWhich would yield approximate maneuver times of the manned interplanetary leg of:-LEO to EML-1 - 7000 m/s (SEP ~30 months)...unmanned-EML-1 to TMI - 650 m/s (chemical, PL stage 1), 200 m/s (SEP ~1 month)-TMI to HMO - 600 m/s (chemical, PL stage 1), 600 m/s (SEP ~3 months)-HMO to TEI -140 m/s (chemical, ITV main engine, PL stage 2), 1350 m/s(SEP ~5 months )-TEI to earth/moon capture - 1300 m/s (SEP ~3 months)It is a bit sluggish at Mars(5 months for TEI). If you look at slide 7 that I updated on the slide deck, that is a potential upgrade path but it uses TRL 6 150 W/kg solar panels vs TRL 9 80 W/kg. That would give you 80% SEP thrust at Mars. Otherwise, to save chemical fuel for TEI, you might look at aerobraking in other maneuvers with the solar array or a second tug that does the TMI burn(which adds a SHLV launch).Ah, so it's a hybrid?600m/s + 650m/s = 1.25km/s.A huge amount of fuel is needed for that, given the first vehicle is roughly 105t+104t+16t at departure. Does it come from the lander? If yes how to land?
Quote from: Oli on 12/25/2016 09:56 pmQuote from: ncb1397 on 12/24/2016 05:46 pmJust to flesh out ideas on how Moon and Mars don't have to be in conflict with each other. And you can do both using assets and technology that NASA already has or is over half-way through the development pipeline.1.5MW is not sufficient for crew transfer given that kind of mass. Or what are the SEP specs?These were the specs that I was working off of:fuel - 35,000 kg Xenonsolar power - 1500 MW @ 1 AUengine power - 1375 MWengine thrust - 23 Nisp - ~9500 secondsMars- ~50% powerEarth- 100% powerWhich would yield approximate maneuver times of the manned interplanetary leg of:-LEO to EML-1 - 7000 m/s (SEP ~30 months)...unmanned-EML-1 to TMI - 650 m/s (chemical, PL stage 1), 200 m/s (SEP ~1 month)-TMI to HMO - 600 m/s (chemical, PL stage 1), 600 m/s (SEP ~3 months)-HMO to TEI -140 m/s (chemical, ITV main engine, PL stage 2), 1350 m/s(SEP ~5 months )-TEI to earth/moon capture - 1300 m/s (SEP ~3 months)It is a bit sluggish at Mars(5 months for TEI). If you look at slide 7 that I updated on the slide deck, that is a potential upgrade path but it uses TRL 6 150 W/kg solar panels vs TRL 9 80 W/kg. That would give you 80% SEP thrust at Mars. Otherwise, to save chemical fuel for TEI, you might look at aerobraking in other maneuvers with the solar array or a second tug that does the TMI burn(which adds a SHLV launch).
Quote from: ncb1397 on 12/24/2016 05:46 pmJust to flesh out ideas on how Moon and Mars don't have to be in conflict with each other. And you can do both using assets and technology that NASA already has or is over half-way through the development pipeline.1.5MW is not sufficient for crew transfer given that kind of mass. Or what are the SEP specs?
Just to flesh out ideas on how Moon and Mars don't have to be in conflict with each other. And you can do both using assets and technology that NASA already has or is over half-way through the development pipeline.
I think the Moon is the only logical choice as a destination for the next several decades at least. It's close for both travel and communication times, it's a stable platform, it has mineral resources that can provide oxygen, metals, water and protection.
Can we have our cake and eat it too?Fund both SX and ULA for the new hardware to the first few new Lunar exploration missions.
Quote from: wannamoonbase on 01/04/2017 03:59 pmI think the Moon is the only logical choice as a destination for the next several decades at least. [...] it has mineral resources that can provide oxygen, metals, water and protection.OTOH it lacks carbon, nitrogen, sulfur, chlorine and other volatiles. Hydrogen availability is questionable.You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry.
I think the Moon is the only logical choice as a destination for the next several decades at least. [...] it has mineral resources that can provide oxygen, metals, water and protection.
Quote from: wannamoonbase on 01/04/2017 03:59 pmI think the Moon is the only logical choice as a destination for the next several decades at least. It's close for both travel and communication times, it's a stable platform, it has mineral resources that can provide oxygen, metals, water and protection.OTOH it lacks carbon, nitrogen, sulfur, chlorine and other volatiles. Hydrogen availability is questionable.You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry.
WMB was speaking in terms of a few decades. It will take a long time before there's enough industry on the moon (or anywhere else) to convert basic hydrocarbons (CO₂, methane, etc) into the full range of complex plastics, paints, solvents, etc, necessary to compete with specialised materials sent from Earth. Bulk commodities alone -- oxygen, water, hydrolox-prop, bulk nickel-iron (from MM-dust), Lunacrete, etc -- represent enough work for decades of development. Highly processed materials, pressure-grade steel, structural aluminium, clear glass, etc, will take even longer.
Quote from: gospacex on 03/06/2017 04:48 pmQuote from: wannamoonbase on 01/04/2017 03:59 pmI think the Moon is the only logical choice as a destination for the next several decades at least. [...] it has mineral resources that can provide oxygen, metals, water and protection.OTOH it lacks carbon, nitrogen, sulfur, chlorine and other volatiles. Hydrogen availability is questionable.You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry.WMB was speaking in terms of a few decades. It will take a long time before there's enough industry on the moon (or anywhere else) to convert basic hydrocarbons (CO₂, methane, etc) into the full range of complex plastics, paints, solvents, etc
Quote from: gospacex on 03/06/2017 04:48 pmQuote from: wannamoonbase on 01/04/2017 03:59 pmI think the Moon is the only logical choice as a destination for the next several decades at least. It's close for both travel and communication times, it's a stable platform, it has mineral resources that can provide oxygen, metals, water and protection.OTOH it lacks carbon, nitrogen, sulfur, chlorine and other volatiles. Hydrogen availability is questionable.You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry.I think you might find all that in the polar crater deposits - even hydrogen, mostly bound in water. These polar craters are really cold, colder than the surface of Pluto, and even if the volatiles are intermixed with some dirt, it should be easier to get them there than to bring them in from the Earth or somewhere else.
Quote from: RocketmanUS on 03/06/2017 01:31 amCan we have our cake and eat it too?Fund both SX and ULA for the new hardware to the first few new Lunar exploration missions.Jon Goff speculated about combining SpaceX/ULA architecture. Sx carries the monkeys in Dragon, ULA launches the lunar lander (XEUS) and ACES TLI/TEI-booster.http://selenianboondocks.com/2017/02/random-thoughts...Functionally "single-bidder" by FAR standards -- since each contractor is exclusively supplying a discrete component -- while actually funding both systems to increase launcher availability for other missions.
Quote from: Bynaus on 03/07/2017 08:47 pmQuote from: gospacex on 03/06/2017 04:48 pmQuote from: wannamoonbase on 01/04/2017 03:59 pmI think the Moon is the only logical choice as a destination for the next several decades at least. It's close for both travel and communication times, it's a stable platform, it has mineral resources that can provide oxygen, metals, water and protection.OTOH it lacks carbon, nitrogen, sulfur, chlorine and other volatiles. Hydrogen availability is questionable.You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry.I think you might find all that in the polar crater deposits - even hydrogen, mostly bound in water. These polar craters are really cold, colder than the surface of Pluto, and even if the volatiles are intermixed with some dirt, it should be easier to get them there than to bring them in from the Earth or somewhere else.I propose that we should check this before we commit to Moon colonization effort. Because what if polar deposits are _not_ as good as we hope?
Just because we can find building materials doesn't mean we have all we need to set up shop on the Moon.Sure it's close, but absent living at the poles
Which brings us back around to asking WHY NASA should refocus on returning to the Moon?
At least the journey to Mars holds the possibility that we'll find life there
and Mars is the most Earth-like planet that is close-by.
So it's not so much where we go that is important, but the WHY and WHEN. Answer those and the WHERE will be obvious.
Quote from: Paul451 on 03/07/2017 08:27 pmWMB was speaking in terms of a few decades. It will take a long time before there's enough industry on the moon (or anywhere else) to convert basic hydrocarbons (CO₂, methane, etc) into the full range of complex plastics, paints, solvents, etcSo, the answer for future Moon colonists "why the hell did we build a colony on a body where a lot of essential materials simply can't be made from local materials?" will be "we did not realize that future will occur"? I thought after Y2000 problem we learned that lesson.
WMB was speaking in terms of a few decades. It will take a long time before there's enough industry on the moon (or anywhere else) to convert basic hydrocarbons (CO₂, methane, etc) into the full range of complex plastics, paints, solvents, etc
Quote from: gospacex on 03/07/2017 09:55 pmI propose that we should check this before we commit to Moon colonization effort. Because what if polar deposits are _not_ as good as we hope?It has been tested. From Clementine through LCROSS.
I propose that we should check this before we commit to Moon colonization effort. Because what if polar deposits are _not_ as good as we hope?
Quote from: Bynaus on 03/08/2017 04:49 amQuote from: gospacex on 03/07/2017 09:55 pmI propose that we should check this before we commit to Moon colonization effort. Because what if polar deposits are _not_ as good as we hope?It has been tested. From Clementine through LCROSS.The data from Clementine was apparently pretty low grade, the two main instruments on LCROSS reportedly contradicted each other.It's clear there's water ice. Lots of water ice. It's less clear what else is in there. Ground-truths are necessary before you even consider designing systems to extract even just the water.That said, it should be scientifically useful. Potentially a chronologically sorted record of hundreds of millions of years of impacts by comets and wet-asteroids. Neatly delineated by thin layers of dust from dry-asteroid impacts. Hence, physically-sorted isotopic samples from countless impactors. A priceless scientific boon.
Quote from: Paul451 on 03/08/2017 10:01 am[polar ice, because "science!"]but I agree, you can always do better by doing a more thorough investigation.
[polar ice, because "science!"]
I am not sure it will be chronologically sorted - you also have gardening by impacts at the poles which might well destroy and mix the top-layer of the deposits as it forms
and the dust from dry asteroid impacts will not easily find its way to the poles (and if it does, it will likely be strongly diluted by regolith dust ejected by the same impact).
However, it might be that volatiles in lunar caves will provide some stratigraphy - protected from impacts, yet very cold, they could be the perfect archives of lunar history (unless the surrounding rock is too warm - so caves near the poles perhaps?). I always wanted to try to model that but never found the time to do it.
I would suggest that the eventual goal would be a functioning interplanetary exploration center and shipyard, where interplanetary spacecraft are built, launched, recovered, refurbished, restocked, re-crewed and launched again.
Fighting only only 1/6 g it shouldn't be much problem to outfit engines strong enough to lift the vehicles into LLO before mission departure.