Author Topic: Methalox ISRU on the Moon?  (Read 22292 times)

Offline Pipcard

  • Full Member
  • ****
  • Posts: 622
  • Liked: 275
  • Likes Given: 130
Methalox ISRU on the Moon?
« on: 04/07/2016 06:38 am »
The Moon is known to hold deposits of water ice, probably in permanently shaded craters. This is thought to be something that can be processed into hydrolox propellant. ULA plans to use that as part of their CisLunar-1000 vision.

But long-term storage of liquid hydrogen is difficult because of boiloff and hydrogen embrittlement. This has led SpaceX to choose methane over hydrogen for its future launch vehicle(s). Methane is "space storable," and does not require as much specialized equipment for zero boil-off capability. If it were possible to develop methalox ISRU for the Moon, there would also be better synergy with propellant manufacturing systems on Mars.

It has been said that
According to LCROSS, the main component of lunar ice is carbon monoxide, then water, then CO2. Lunar poles ISRU is quite similar to Mars ISRU in that sense.

The lunar cold traps could accumulate other cometary volatiles besides water.

LCROSS ejecta:
N   6.6000%
CO   5.7000%
H2O   5.5000%
Zn   3.1000%
V   2.4000%
Ca   1.6000%
Au   1.6000%
Mn   1.3000%
Hg   1.2000%
Co   1.0000%
H2S   0.9213%
Fe   0.5000%
Mg   0.4000%
NH3   0.3317%
Cl   0.2000%
SO2   0.1755%
C2H4   0.1716%
CO2   0.1194%
C   0.0900%
Sc   0.0900%
Ch3OH   0.0853%
S    0.0600%
B   0.0400%
P   0.0400%
CH4   0.0366%
O   0.0200%
Si   0.0200%
As   0.0200%
Al   0.0090%
OH   0.0017%

As you can see, there's some carbon. Lots of nitrogen too. If the volatiles kicked up by LCROSS came from the same source as the ice sheets detected by mini-SAR radar, there may be abundant carbon compounds there as well as water.

But the issue is that the Sabatier Reaction that is a part of Mars ISRU requires carbon dioxide (which was a much smaller component of the observed ejecta), and carbon monoxide is a waste product (because it was the result of obtaining oxygen from the CO2). I do not know everything about chemistry, so is there any way to turn CO (and hydrogen electrolyzed from water) into methane/LOX propellant?
« Last Edit: 04/07/2016 06:52 am by Pipcard »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #1 on: 04/07/2016 04:11 pm »
Combine it with some of the output oxygen from electrolyzing the water. This still works out because usually you want a fuel-rich mix anyway.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #2 on: 04/07/2016 05:30 pm »
Methane is "space storable,"

Can you cite a reference ? Because currently it is not, and as far as i know, not in the foreseeable future. See the reference chart from Handbook of Space technology, ISBN: 9780470697399

Also, there are previous threads on this.
Orion - the first and only manned not-too-deep-space craft

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #3 on: 04/07/2016 07:00 pm »
Methane is "space storable,"

Can you cite a reference ? Because currently it is not, and as far as i know, not in the foreseeable future. See the reference chart from Handbook of Space technology, ISBN: 9780470697399

Also, there are previous threads on this.
It indeed is. You store it in the shade. If your vehicle is a cylinder, have the long axis of the cylinder point toward the Sun. Make sure you use emissivity-optimized paint.

There is no single "temperature" in space. Although you do have to go to extremes to keep hydrogen and helium from boiling off, it's not terribly difficult to keep methane and oxygen from doing so. Note that spacecraft normally get pretty cold in space already, to the extent that hypergolic fuels actually need to be actively heated to prevent them from freezing.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Doesitfloat

  • Full Member
  • ***
  • Posts: 334
  • Detroit MI
  • Liked: 499
  • Likes Given: 197
Re: Methalox ISRU on the Moon?
« Reply #4 on: 04/07/2016 07:01 pm »
https://www.nasa.gov/feature/in-space-manufacture-of-storable-propellants

Above is link to NASA site for" In-Space Manufacture of Storable Propellants"
Updated Feb 2016

Site lists the following as propellants:
Hydrogen
Oxygen
Methane
Methanol
Dimethyl Ether
Hydrogenperoxide

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #5 on: 04/07/2016 07:39 pm »
https://www.nasa.gov/feature/in-space-manufacture-of-storable-propellants

Above is link to NASA site for" In-Space Manufacture of Storable Propellants"
Updated Feb 2016
NASA website also has blog posts about other futuristic stuff, like NIAC interstellar propulsion studies. Just because that blog post from a SBIR company  ( that to date, has not actually flown anything to space ) is published on nasa.gov does not change the current state of the art in space technology.

There is a long way to go before either LOX or Methane can be classified as space storable propellants.
Orion - the first and only manned not-too-deep-space craft

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #6 on: 04/07/2016 08:19 pm »
https://www.nasa.gov/feature/in-space-manufacture-of-storable-propellants

Above is link to NASA site for" In-Space Manufacture of Storable Propellants"
Updated Feb 2016
NASA website also has blog posts about other futuristic stuff, like NIAC interstellar propulsion studies. Just because that blog post from a SBIR company  ( that to date, has not actually flown anything to space ) is published on nasa.gov does not change the current state of the art in space technology.

There is a long way to go before either LOX or Methane can be classified as space storable propellants.
Nope. In your opinion alone.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Methalox ISRU on the Moon?
« Reply #7 on: 04/07/2016 08:48 pm »
Although I tend to give Robotbeat a bit more credence here "you're wrong" ... "no, you're the wrong one", "no you" tends to be quite boring.  Rather than argue about who said what was storable and when, perhaps it would be more instructive to discuss for all our edification what exactly the criteria for storables are.

I had thought that any propellant that could be stored, without suffering boiloff, in LEO or in deep space with only passive temperature control was pretty obviously storable. Is there more to it than that? Is it still storable if it requires active control, but doesn't have to boil off (solar/battery providing energy to drive cooling or heating systems, perhaps)?

THAT said, perhaps the question actually belongs somewhere else... and we should confine discussion in this thread to whether we know enough about lunar ice or other carbon sources to know if methalox ISRU is feasible or not. That's the thread title, not storable propellants...

Some of the prior discussion on lunar methalox seemed to assume that carbon was brought along somehow (just as some early martian methalox assumed hydrogen is brought along) ... is modern thinking still going that way at all?

LCROSS data is interesting but it may be we won't know until we actually send a prospector to take some samples and assay them.
« Last Edit: 04/07/2016 08:52 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Oli

  • Senior Member
  • *****
  • Posts: 2467
  • Liked: 605
  • Likes Given: 60
Re: Methalox ISRU on the Moon?
« Reply #8 on: 04/07/2016 10:29 pm »
The methalox stages in NASA's recent Mars plan have cryocoolers. The stages are assembled is cis-lunar space or shipped to Mars orbit with SEP (takes several years).
« Last Edit: 04/07/2016 10:31 pm by Oli »

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #9 on: 04/08/2016 02:25 am »
I do not know everything about chemistry, so is there any way to turn CO (and hydrogen electrolyzed from water) into methane/LOX propellant?

This is done with something called Fischer–Tropsch process, where for terrestrial Gas-to-Liquids plants methane is often an unwanted side product
Orion - the first and only manned not-too-deep-space craft

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39215
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32735
  • Likes Given: 8178
Re: Methalox ISRU on the Moon?
« Reply #10 on: 04/08/2016 09:07 am »
Reverse steam reforming should do the trick.

CO + 3H2 -> CH4 + H2O, Delta H = –206 kJ/mol

This is an exothermic process. A catalyst might be required. The Hydrogen can be obtained from electrolysing H2O

3H2O -> 3H2 + 1.5O2, Delta H = 711 kJ/mol

Overall reaction is

CO + 2H2O -> CH4 + 1.5O2, Delta H = 505 kJ/mol

That's an oxidiser to fuel ratio of 2.99. Ideally, would like a ratio of 3.5 to 1, which means generating more oxygen. That means 0.255 more O2 will need to be generated.

CO + 2.51H2O -> CH4 + 1.755O2 + 0.51H2
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline RocketmanUS

  • Senior Member
  • *****
  • Posts: 2226
  • USA
  • Liked: 71
  • Likes Given: 31
Re: Methalox ISRU on the Moon?
« Reply #11 on: 04/10/2016 07:01 pm »
{snip}
LCROSS data is interesting but it may be we won't know until we actually send a prospector to take some samples and assay them.
Agree, need to send probes to Lunar surface to confirm if there is carbon source(s) and enough of it.

Morpheus could have been a possible lander for such types of prospector probes.

Offline R7

  • Propulsophile
  • Senior Member
  • *****
  • Posts: 2725
    • Don't worry.. we can still be fans of OSC and SNC
  • Liked: 992
  • Likes Given: 668
Re: Methalox ISRU on the Moon?
« Reply #12 on: 04/13/2016 08:04 am »
NASA website also has blog posts about other futuristic stuff, like NIAC interstellar propulsion studies. Just because that blog post from a SBIR company  ( that to date, has not actually flown anything to space ) is published on nasa.gov does not change the current state of the art in space technology.

There is a long way to go before either LOX or Methane can be classified as space storable propellants.

Methane would freeze behind JWST sun shield. Heck, even oxygen would freeze there.

Equating passive thermal management involving reflective surfaces with NIAC breakthru interstellar ambitions is intellectually lazy.
AD·ASTRA·ASTRORVM·GRATIA

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #13 on: 04/13/2016 03:55 pm »
Methane would freeze behind JWST sun shield. Heck, even oxygen would freeze there.

Equating passive thermal management involving reflective surfaces with NIAC breakthru interstellar ambitions is intellectually lazy.
My point is, that propellant isn't a propellant without a functioning propulsion subsystem. You can call a rock propellant, but lacking a functioning mass driver it isn't much of use.
And a liquid biprop propulsion subsystem, especially one that is supposed to fire up after spending months and years in deep space, requires quite a bit more than a tank or a sun shield.
For current space storable propellants, all the required subsystems are catalog items.
Orion - the first and only manned not-too-deep-space craft

Offline R7

  • Propulsophile
  • Senior Member
  • *****
  • Posts: 2725
    • Don't worry.. we can still be fans of OSC and SNC
  • Liked: 992
  • Likes Given: 668
Re: Methalox ISRU on the Moon?
« Reply #14 on: 04/13/2016 04:55 pm »
My point is, that propellant isn't a propellant without a functioning propulsion subsystem.

It is pointless to argue against lunar methalox ISRU with "current catalogs lack methalox engine therefore no" argument. The methalox ISRU concept happens in the future (if it happens) and obviously assumes that catalogs then do have methalox engines and actual customers using them.

At least two companies are working on methalox engines, and the other plans to use them to get to Mars.
AD·ASTRA·ASTRORVM·GRATIA

Offline gospacex

  • Senior Member
  • *****
  • Posts: 3024
  • Liked: 543
  • Likes Given: 604
Re: Methalox ISRU on the Moon?
« Reply #15 on: 04/13/2016 05:42 pm »
https://en.wikipedia.org/wiki/Moon#Physical_characteristics

doesn't look good. Basically, both C and H are rare.

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Methalox ISRU on the Moon?
« Reply #16 on: 04/13/2016 06:08 pm »
https://en.wikipedia.org/wiki/Moon#Physical_characteristics

doesn't look good. Basically, both C and H are rare.
When viewing the earth as a whole, gold is "rare". And yet people found gold nuggets in streams.

What matters is not what the overall ratios are, but rather whether there are usable concentrations in sufficient quantity to be useful.   700 years from now our ancestors may be cursing that we used up most of the findable CO and H20 on Luna for fuel :) ... but I think LCROSS has shown there is usable water to be found.

From the same WP article
Quote
The 2008 Chandrayaan-1 spacecraft has since confirmed the existence of surface water ice, using the on-board Moon Mineralogy Mapper. The spectrometer observed absorption lines common to hydroxyl, in reflected sunlight, providing evidence of large quantities of water ice, on the lunar surface. The spacecraft showed that concentrations may possibly be as high as 1,000 ppm.[89] In 2009, LCROSS sent a 2,300 kg (5,100 lb) impactor into a permanently shadowed polar crater, and detected at least 100 kg (220 lb) of water in a plume of ejected material.[90][91] Another examination of the LCROSS data showed the amount of detected water to be closer to 155 ± 12 kg (342 ± 26 lb).[92]
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline gospacex

  • Senior Member
  • *****
  • Posts: 3024
  • Liked: 543
  • Likes Given: 604
Re: Methalox ISRU on the Moon?
« Reply #17 on: 04/13/2016 06:26 pm »
1000 ppm of water? That's about as much water as in a typical block of concrete.

Offline Nilof

  • Full Member
  • ****
  • Posts: 1177
  • Liked: 597
  • Likes Given: 707
Re: Methalox ISRU on the Moon?
« Reply #18 on: 04/13/2016 11:31 pm »
1000 ppm of water? That's about as much water as in a typical block of concrete.
That is for regolith, the moon has vast water ice, carbon monoxide, and nitrogen deposits in polar cold traps. Saying that the moon lacks volatiles because regolith is dry is like looking at Egypt and ignoring the fact that the Nile exists. The poles have more than enough volatiles for very large scale colonization.
« Last Edit: 04/15/2016 01:16 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #19 on: 04/14/2016 12:04 am »
My point is, that propellant isn't a propellant without a functioning propulsion subsystem.

It is pointless to argue against lunar methalox ISRU with "current catalogs lack methalox engine therefore no" argument. The methalox ISRU concept happens in the future (if it happens) and obviously assumes that catalogs then do have methalox engines and actual customers using them.

At least two companies are working on methalox engines, and the other plans to use them to get to Mars.
Besides Blue Origin and SpaceX, you also have Masten Space Systems working on a 60klbf methane engine, which they've already test-fired a 45klbf variant. Also, Armadillo Aerospace (now still alive as Exos Aerospace) developed a methane engine used on NASA's VTVL test-bed. Plus Firefly Space Systems, who have also test-fired their upper stage methane rocket engine. Plus XCOR, who test-fired a methane rocket engine a while ago.

So that's 6 separate methane rocket engines in the US alone that have been test-fired recently. In 10 years, every orbital fully liquid rocket in the US may use methane for at least one stage (with the possible exception of RocketLabs and Virgin's LauncherOne if they get built). Pretty absurd to consider methane some exotic propellant.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #20 on: 04/14/2016 01:00 am »
A video of a methane/LOX rocket engine being flight tested at KSC.



This was Project Morpheus Free Flight 13 on Thursday, May 22, 2014. The HD5 has an Isp of 321 seconds and produces 24,000 N ( 5,400 lbf) of thrust.

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #21 on: 04/14/2016 01:34 am »
My point is, that propellant isn't a propellant without a functioning propulsion subsystem.

It is pointless to argue against lunar methalox ISRU with "current catalogs lack methalox engine therefore no" argument. The methalox ISRU concept happens in the future (if it happens) and obviously assumes that catalogs then do have methalox engines and actual customers using them.

At least two companies are working on methalox engines, and the other plans to use them to get to Mars.
Besides Blue Origin and SpaceX, you also have Masten Space Systems working on a 60klbf methane engine, which they've already test-fired a 45klbf variant. ...Pretty absurd to consider methane some exotic propellant.
Not sure why you insist arguing a strawman ? Methane rockets have been fired for a long time, all around the world, and your list isnt even nearly exhaustive. Many other liquid, hybrid and solid propellant configurations have long history in various applications, which has little to do with them being space storable.

Orion - the first and only manned not-too-deep-space craft

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #22 on: 04/14/2016 01:38 am »
It is time to devise and test tanks that can store methane and LOX for up to 4 years.

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #23 on: 04/14/2016 02:01 am »
It is time to devise and test tanks that can store methane and LOX for up to 4 years.
And again, its not just about tanks, injectors or nozzles. Pesky little details like transducers, regulators, latch and pyro valves, filters, thermal equipment like valve heaters etc etc. And then on top of traditional SOA deep space biprops like NTO/MMH you add ignition systems, active thermal management and a bunch of other details.
Companies like Vacco, Marotta , Paine, Conax and many others have been in the business of providing space qualified versions of such for spacecraft for commercial customers for decades. For a fun excercise, go try and quote a LOX compatible pyro valve from one of these, for lead time and tested batch price.
« Last Edit: 04/14/2016 02:01 am by savuporo »
Orion - the first and only manned not-too-deep-space craft

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Methalox ISRU on the Moon?
« Reply #24 on: 04/14/2016 02:19 am »
For a fun excercise, go try and quote a LOX compatible pyro valve from one of these, for lead time and tested batch price.

Because you have to use those suppliers and could never bring this technology in house...  Whatever SpaceX is doing? Clearly all wrong, look at their spectacular failures, one failure after another. They are going to run out of money soon, for sure.

Sorry, that was sarcasm and that's not appropriate. But I think maybe I'm a bit frustrated at the naysaying... I think people get that yes, there's work to be done before you have a methalox based system that's storable in the conditions that will be faced, but I think that to suggest everything is TRL1 is also wrong.
« Last Edit: 04/14/2016 02:20 am by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #25 on: 04/14/2016 02:55 am »
Because you have to use those suppliers and could never bring this technology in house...  Whatever SpaceX is doing?
And commercial spacecraft industry has existed for much longer than SpaceX. I fail to understand how SpaceX is relevant to everything that happens in space.
There are thousands of very talented individuals in space industry across the world. There are also textbooks and engineering courses. Mere existence of SpaceX has not rewritten any textbooks or invalidated decades of cumulative experience, especially in parts that they haven't even touched yet.
It's also generally respectful to not assume that thsee people that have built myriad of complicated spacecraft don't really have a clue

And to the point of "building everything in house" - nobody does that for many good reasons that would be even more off topic here, not SpaceX nor anyone else
 
Quote
Sorry, that was sarcasm and that's not appropriate.

Unnecessary and tiresome

Quote
But I think maybe I'm a bit frustrated at the naysaying...
Making a distinction between engineering state of art, and future ideas that might happen or might get superseded by something completely different isn't naysaying in my book.


Quote
but I think that to suggest everything is TRL1 is also wrong.
I happen to know exactly where deep space lox/ch4 propulsion is pegged at in the TRL ladder by more than one evaluating agency, please don't argue things that nobody has said.
Orion - the first and only manned not-too-deep-space craft

Offline strangequark

  • Full Member
  • ****
  • Posts: 1072
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 226
  • Likes Given: 12
Re: Methalox ISRU on the Moon?
« Reply #26 on: 04/14/2016 03:43 am »
It is time to devise and test tanks that can store methane and LOX for up to 4 years.
For a fun excercise, go try and quote a LOX compatible pyro valve from one of these, for lead time and tested batch price.

About $1-2 million for the qual, and 52 weeks on the first lot. Not sure the point you're trying to make. Plenty of catalog components that are useable with methane.

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 5266
  • Sunnyvale, CA
  • Liked: 4992
  • Likes Given: 6459
Re: Methalox ISRU on the Moon?
« Reply #27 on: 04/14/2016 03:49 am »
Because you have to use those suppliers and could never bring this technology in house...  Whatever SpaceX is doing?
And commercial spacecraft industry has existed for much longer than SpaceX. I fail to understand how SpaceX is relevant to everything that happens in space.

Nobody said SpaceX is relevant to everything that happens in space.  Lar was mentioning SpaceX here because they're a counterexample to your claim that methane is not a space-storable propellant.  SpaceX plans to use methane as a space-storable propellant.  That's how it's relevant.

There are thousands of very talented individuals in space industry across the world. There are also textbooks and engineering courses. Mere existence of SpaceX has not rewritten any textbooks or invalidated decades of cumulative experience, especially in parts that they haven't even touched yet.
It's also generally respectful to not assume that thsee people that have built myriad of complicated spacecraft don't really have a clue

Nobody said those people don't have a clue.  Those people who built many other spacecraft never claimed methane isn't a space-storable propellant.  But GM and Ford building only gas-powered cars for decades doesn't mean electric vehicles are impossible, and other people building spacecraft that use propulsion other than methane for long-duration spacecraft doesn't mean methane is impossible as an alternative.

And to the point of "building everything in house" - nobody does that for many good reasons that would be even more off topic here, not SpaceX nor anyone else
 
Quote
Sorry, that was sarcasm and that's not appropriate.

Unnecessary and tiresome

Glass houses.

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #28 on: 04/14/2016 06:42 am »
It is time to devise and test tanks that can store methane and LOX for up to 4 years.
For a fun excercise, go try and quote a LOX compatible pyro valve from one of these, for lead time and tested batch price.

About $1-2 million for the qual, and 52 weeks on the first lot. Not sure the point you're trying to make. Plenty of catalog components that are useable with methane.

We have not built transfer vehicles designed to work in space for years. However we have built probes and satellites weighing many tons whose RCS use thrusters that work for 10-15 years in space.

The information and design specifications of the parts may be transferable. IMHO it is worthwhile someone spending a day to ensure that the engines, plumbing, avionics and structure of long lived vehicles like ACES, rovers and SpaceX's Mars vehicles are using the tougher standards.

Offline R7

  • Propulsophile
  • Senior Member
  • *****
  • Posts: 2725
    • Don't worry.. we can still be fans of OSC and SNC
  • Liked: 992
  • Likes Given: 668
Re: Methalox ISRU on the Moon?
« Reply #29 on: 04/14/2016 07:18 am »
Making a distinction between engineering state of art, and future ideas that might happen or might get superseded by something completely different isn't naysaying in my book.

You didn't make such distinction.

Quote
Because currently it is not, and as far as i know, not in the foreseeable future.

Perhaps you'd like to elaborate how far is foreseeable future and what reasons prevent space storable methalox propulsion systems from happening during that time.
AD·ASTRA·ASTRORVM·GRATIA

Offline Oli

  • Senior Member
  • *****
  • Posts: 2467
  • Liked: 605
  • Likes Given: 60
Re: Methalox ISRU on the Moon?
« Reply #30 on: 04/14/2016 12:13 pm »
Those people who built many other spacecraft never claimed methane isn't a space-storable propellant.

In all the papers I've read I've never seen anyone refering to LCH4 as "storable propellant", it's cryogenic. Of course every propellant is potentially storable in space, depends on the spacecraft and the distance to the sun.

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Methalox ISRU on the Moon?
« Reply #31 on: 04/14/2016 02:54 pm »
Suppose we say that yes, under the definition of "doesn't need active heating or cooling, can be stored passively, maybe with some shading but nothing else...." Methalox isn't "storable".. Now what?

To me it means that if we want long duration missions that use methalox, or that we want propellant depots, they are going to have to do some systems development... some active (powered) heating and cooling systems have to be developed and brought to sufficient TRL to be worth demonstrating in space as the success chances are high enough.

Can we say "yep, thats all true"... agree with each other, hold hands, sing kumbaya, whatever...

..., and get back to whether methalox ISRU is viable on Luna? Assume it would need active storage. (and don't mention it again, we all agree...)
« Last Edit: 04/14/2016 02:56 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5152
  • Liked: 1002
  • Likes Given: 342
Re: Methalox ISRU on the Moon?
« Reply #32 on: 04/14/2016 03:31 pm »
..., and get back to whether methalox ISRU is viable on Luna? Assume it would need active storage. (and don't mention it again, we all agree...)
If you assume ISRU is feasible in the first place with regolith processing, then the theoretical answer is yes. We know all the elements are there in regolith. Practical answer depends on much better understanding of lunar volatiles.

Quote
Analysis of these data sets suggests the presence of volatiles, including water,  hydrogen,  carbon monoxide,  methane,  and others, though their concentration and distribution, both laterally and vertically, seem to be quite variable, and their physical form is not clear.

There have been previous brief studies of of LOX/LH vs LOX/CH4 on the moon. In all likelihood, if we had the actual capabilities, we'd try both.


Perhaps you'd like to elaborate how far is foreseeable future and what reasons prevent space storable methalox propulsion systems from happening during that time.

I'll comment on this and leave it at that. There are no spacecraft currently being designed with integrated LOX/CH4 main propulsion or RCS. The reasons for this are somewhat obvious: for methalox to win against state of art storable biprops like NTO/MMH and NTO/N2H4 in design trades you'd need a fairly unique set of conditions. The ISP jump from 325~ to 350~ ( pressure fed obv. ) becomes relevant mostly for ascent and earth return applications, and then a spacecraft designer have to eat all the extra risk, timelines and complexity of flying things with no previous heritage. The spacecraft requiring these applications are few and far between.
It's unlikely that Chang'e-5 will tool around with cryogens, they have more pressing issues, and the next realistic candidate is a MAV for MSR. There is technical risk reduction work being done in more than one place to mature the required subsystems beyond TRL4-5 for methalox to become a credible option, so when a MSR mission actually does become a real prospect it might get picked.
A credible option would be to fly a purely tech maturation mission with similar goals to SMART-1 and DS-1, or most anything from New Millenium program, but then there are not so many ways of gettings such missions funded these days.
Hence, foreseeable future. I'm sure there are knowledgeable people with clearer foresight, but then history has shown that even for the best the future remains hard to predict. Except for Hari Seldon.
( And once again, i have not claimed methalox in-space propulsion is impossible or cant happen, it's obviously highly desireable, like many other things on space technology wish lists that tend to advance very slowly )
« Last Edit: 04/14/2016 04:45 pm by savuporo »
Orion - the first and only manned not-too-deep-space craft

Offline Nilof

  • Full Member
  • ****
  • Posts: 1177
  • Liked: 597
  • Likes Given: 707
Re: Methalox ISRU on the Moon?
« Reply #33 on: 04/15/2016 01:00 am »
...How is it relevant to this thread whether cryogenics are storable on orbit or not? A lunar poles surface depot has an easier thermal environment than Mars for Methalox storage. A reusable lander does not need to pull off Methalox storage for the same reason that earth-based launch vehicles don't, it just needs an endurance of a few hours and the ability to reignite.

Now, the LCROSS data posted in the original post of this thread shows that the cold traps do have nitrogen available(with a similar mass fraction to water and carbon monoxide), so if orbit-storable propellant ISRU is desired, an ammonia production facility would enable making nitrogen tetroxide as an alternative to LOX. Alternatively, you could go for hydrogen peroxide production. If you do both you could make both hydrazine and nitrogen tetroxide.
« Last Edit: 04/15/2016 01:23 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #34 on: 04/15/2016 03:39 pm »
Suppose we say that yes, under the definition of "doesn't need active heating or cooling, can be stored passively, maybe with some shading but nothing else...." Methalox isn't "storable".. Now what?

To me it means that if we want long duration missions that use methalox, or that we want propellant depots, they are going to have to do some systems development... some active (powered) heating and cooling systems have to be developed and brought to sufficient TRL to be worth demonstrating in space as the success chances are high enough.

Can we say "yep, thats all true"... agree with each other, hold hands, sing kumbaya, whatever...

..., and get back to whether methalox ISRU is viable on Luna? Assume it would need active storage. (and don't mention it again, we all agree...)
Well obviously you'll need active storage on the Moon since you'll have to be liquifying it after producing the gas.

But not in space. Space-storable, not lunar storable. No active cooling is necessarily required for zero-boiloff methane and oxygen storage in space.
« Last Edit: 04/15/2016 03:40 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline R7

  • Propulsophile
  • Senior Member
  • *****
  • Posts: 2725
    • Don't worry.. we can still be fans of OSC and SNC
  • Liked: 992
  • Likes Given: 668
Re: Methalox ISRU on the Moon?
« Reply #35 on: 04/15/2016 04:29 pm »
Well obviously you'll need active storage on the Moon since you'll have to be liquifying it after producing the gas.

Active storage? There are even natural PSRs where temps down to 26K. Elsewhere construct an artificial one. Tent poles and reflective foil ;)
AD·ASTRA·ASTRORVM·GRATIA

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Methalox ISRU on the Moon?
« Reply #36 on: 04/15/2016 04:40 pm »
My point was that you'll need the cryocoolers anyway, so even if passive boiloff is too difficult to achieve during the lunar day, you already have all the equipment necessary to keep the propellant liquid.

But definitely a good point. Cold traps on the Moon show that achieving passive cryogenic temperatures is not particularly hard given sufficient shielding of sunlight.
« Last Edit: 04/15/2016 04:41 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #37 on: 04/18/2016 02:39 pm »
Well obviously you'll need active storage on the Moon since you'll have to be liquifying it after producing the gas.

Active storage? There are even natural PSRs where temps down to 26K. Elsewhere construct an artificial one. Tent poles and reflective foil ;)

At 26K heaters will need adding to the LOX and methane tanks to keep the propellant liquid.

Online sdsds

  • Senior Member
  • *****
  • Posts: 7202
  • “With peace and hope for all mankind.”
  • Seattle
  • Liked: 2050
  • Likes Given: 1962
Re: Methalox ISRU on the Moon?
« Reply #38 on: 11/30/2016 04:07 am »
There are no spacecraft currently being designed with integrated LOX/CH4 main propulsion or RCS.

So that was the past. Does the ITS vehicle count as a spacecraft currently being designed and if so, does that change the "state of play" in this regard?
— 𝐬𝐝𝐒𝐝𝐬 —

Offline KelvinZero

  • Senior Member
  • *****
  • Posts: 4286
  • Liked: 887
  • Likes Given: 201
Re: Methalox ISRU on the Moon?
« Reply #39 on: 11/30/2016 10:00 am »
Methane on the moon is apparently disputed. We really really just have to go and have a look. It is so frustrating. So many billions have flowed since then and it is just not a priority. :p

Yes. The buzz-phrase for this is to say there is a "Strategic Knowledge Gap" regarding (in particular for this thread) lunar ice.
Also there is meant to be more CO than H2O in the LCROSS results so lunar methane ISRU sounds plausible and arguably less wasteful of all those volatiles.

I know this piece of common knowledge (that LCROSS found more CO than H2O) has been repeated a lot on NSF, but it may not be accurate, based on a conversation I had with Paul Spudis:

http://forum.nasaspaceflight.com/index.php?topic=39559.msg1612453#msg1612453

tl;dr is that only one of the two sensors showed less H2O, and it's the one they trust a lot less. The IR mass spectrometer data on the LCROSS shepherding craft showed 90-95% of the volatiles were water, and its results have never been revised downward. The LAMP data from LRO (which was within line-of-site for the impact) was revised downward, but we have a lot less experience with interpreting UV spectrometry than we do IR spectrometry.

~Jon

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #40 on: 11/30/2016 01:19 pm »
Does any of the replies to the small lunar surface payloads request for information included a methane detector?
There is still time to add one because the deadline for responses is December 9, 2016
https://www.nasa.gov/feature/nasa-seeks-additional-information-on-small-lunar-surface-payloads

Offline jongoff

  • Recovering Rocket Plumber/Space Entrepreneur
  • Senior Member
  • *****
  • Posts: 6807
  • Lafayette/Broomfield, CO
  • Liked: 3987
  • Likes Given: 1684
Re: Methalox ISRU on the Moon?
« Reply #41 on: 11/30/2016 03:30 pm »
Methane on the moon is apparently disputed. We really really just have to go and have a look. It is so frustrating. So many billions have flowed since then and it is just not a priority. :p

Yeah, it is disputed. I worry that so many people hate hydrogen and like Mars that when they saw data suggesting Methalox could work on the Moon, they kicked into bias-confirmation mode. They could still be right, but at least for me, my bias-confirmation mode suggests that the preponderence of the data always suggested water being a lot more common than CO or CO2...

More data would be awesome. Particularly ground-truth data.

~Jon
« Last Edit: 11/30/2016 03:31 pm by jongoff »

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #42 on: 11/30/2016 06:14 pm »

Yeah, it is disputed. I worry that so many people hate hydrogen and like Mars that when they saw data suggesting Methalox could work on the Moon, they kicked into bias-confirmation mode. They could still be right, but at least for me, my bias-confirmation mode suggests that the preponderence of the data always suggested water being a lot more common than CO or CO2...

More data would be awesome. Particularly ground-truth data.

~Jon

Ground truthing will require something like a mass spectrometer to be sent to the Moon. If we are going to send rovers into the permanently dark craters on the Moon for more than a few hours they will have to be nuclear powered. Since the Department of Energy is going to be very short of Plutonium for the next decade or so a different radioactive material is needed.  Fortunately the rover will only need to operate for 2 or 3 years so only a medium half life in needed. Stirling engines do not care what the heat source is providing there is sufficient heat.

Offline TrevorMonty

Re: Methalox ISRU on the Moon?
« Reply #43 on: 11/30/2016 07:04 pm »
Do you need a rover, a lander could work just as well. Land in crater hop between sites and fly back to sunlight all before it gets to cold.

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Methalox ISRU on the Moon?
« Reply #44 on: 11/30/2016 10:59 pm »
Do you need a rover, a lander could work just as well. Land in crater hop between sites and fly back to sunlight all before it gets to cold.

It will not take many hops before the lander runs out of fuel.

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Methalox ISRU on the Moon?
« Reply #45 on: 11/30/2016 11:31 pm »
Do you need a rover, a lander could work just as well. Land in crater hop between sites and fly back to sunlight all before it gets to cold.

It will not take many hops before the lander runs out of fuel.

That rocket equation is such a pain.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline TrevorMonty

Re: Methalox ISRU on the Moon?
« Reply #46 on: 11/30/2016 11:41 pm »
Do you need a rover, a lander could work just as well. Land in crater hop between sites and fly back to sunlight all before it gets to cold.

It will not take many hops before the lander runs out of fuel.
For most craters one or two samples should be enough to prove if further investigation is required.

Offline KelvinZero

  • Senior Member
  • *****
  • Posts: 4286
  • Liked: 887
  • Likes Given: 201
Re: Methalox ISRU on the Moon?
« Reply #47 on: 12/01/2016 12:35 am »
Do you need a rover, a lander could work just as well. Land in crater hop between sites and fly back to sunlight all before it gets to cold.
Im very much in favour of a rover just because we could have it running for _years_. The difference between just one sample and actually exploring is so huge. The rovers on mars have been spectacularly successful and a lunar rover could be far more convenient due to hugely lower lag.

There are some technical issues with the poles but potentially it is a very benign environment compared to other parts of the moon. I would like to go into the craters, which requires a significant power source, though we could probably learn a lot with a solar powered rover that just skirted the edges and had something like that laser that Curiosity uses.

I would like us to always have a rover or two puttering around on the moon. My vote is roveroverover!

Tags:
 

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