SpaceX Interplanetary Transport System (updates)


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Great NSF article about Raptor by Alejandro Belluscio,

 

https://www.nasaspaceflight.com/2016/10/its-propulsion-evolution-raptor-engine/

 

Key points

 

1) The Raptor on the McGregor test stand is 1 meganewton, or about 225,000-230,000 lbf, about 1/3 scale. The full engine is >3 meganewtons.

 

Me: the RS-25 Space Shuttle Main Engine is 1.86 - 2.28 meganewtons. 1 meganewton is  perfect for the USAF. Falcon 9/FH upper stage project. Being subscale matters not as Full Flow Staged Combustion engines scale easily, unlike most other cycles.

 

2) Raptor is about 40% 3D printed.

 

Me: no surprise as it lets you prototype quickly, and NASA studies show it can reduce the parts count by 90% and weight significantly. Parts can be made which are impossible using traditional machining, an example being the SuperDraco engine.

 

3) electric spark ignition. Unlimited restarts, no more TEA-TEB pyrophoric ignition fluids.

 

4) could break Merlin 1D's record breaking power to weight ratio of 198:1.

 

Me: A street fighter not much larger than Merlin 1D.

 

5) 3 known variants with throat area ratios of 40, 50 and 150.

 

Observation: it appears the blast cells which protect Merlin 1D engines from fratricde in the F9/FH Octaweb are now part of the Raptor engine.  See image below, which shows where the shell is cut away.

 

Ladies and gents, we have a monster more powerful and far more mass efficient than the RS-25 Space Shuttle Main Engine/SLS core engine.

 

Raptor (armor) sm.jpg.

 

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On 02/10/2016 at 11:35 PM, SALSN said:

Even though it might not be the right place, I think the question about sanitation and waste recycling is quite interesting, but perhaps that is just because I just finished the Martian for the second time :-P

I don't think the question itself was the problem, but more in how it was phrased... Really, there was no need to use the crude language the questioner used, Elon just looked embarrassed...

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As a side note...comedy time

 

Boeing CEO Vows to Beat Musk to Mars

 

Quote

Boeing Co. once helped the U.S. beat the Soviet Union in the race to the moon. Now the company intends to go toe-to-toe with newcomers such as billionaire Elon Musk in the next era of space exploration and commerce.


Boeing Chief Executive Officer Dennis Muilenburg sketched out a Jetsons-like future at a conference Tuesday, envisioning a commercial space-travel market with dozens of destinations orbiting the Earth and hypersonic aircraft shuttling travelers between continents in two hours or less. And Boeing intends to be a key player in the initial push to send humans to Mars, maybe even beating Musk to his long-time goal.

 

“I’m convinced the first person to step foot on Mars will arrive there riding a Boeing rocket,” Muilenburg said at the Chicago event on innovation, which was sponsored by the Atlantic magazine.

https://www.bloomberg.com/news/articles/2016-10-04/boeing-ceo-vows-to-beat-musk-to-mars-as-new-space-race-beckons

 

Boeing and powerpoint...no real plan but most importantly...no money from the trough, meaning this is a PR stunt.

 

SpaceX has really riled "oldspace"  but as always, oldspace can't do anything unless it has taxpayers money...of which there is no amount for their cost structure.

 

On a good note...SpaceX support...

 

Congress members pen letter to FAA in support of SpaceX investigation

 

Quote

Last week, a congressional delegation with ties to SpaceX competitor ULA issued an open letter to the FAA, criticizing their admittedly fully legal self-directed investigation into the cause of the early September Falcon 9 rocket explosion. Now, a group of 24 bipartisan members of congress have issued a retort.

 

This letter maintains that SpaceX has conducted the investigation in keeping with the established practice, which is true, and urges the FAA to ignore entreaties it claims aim to “politicize” the investigation, and implies that the purpose of doing so would be to hamper SpaceX’s ability to operate competitively with other, more established players. 

https://techcrunch.com/2016/10/04/congress-members-pen-letter-to-faa-in-support-of-spacex-investigation/

 

IAC 2016 woke up a few....:D

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A question!  I see a lot of talk about making fuel on Mars, but I've yet to see anyone talking about how to actually MINE the materials needed to make the fuel.  Just how do they plan to go about actually doing that?  

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1 hour ago, FloatingFatMan said:

A question!  I see a lot of talk about making fuel on Mars, but I've yet to see anyone talking about how to actually MINE the materials needed to make the fuel.  Just how do they plan to go about actually doing that?  

There are 2 things needed to use a Sabatier reactor for making methane and oxygen on Mars; carbon dioxide and hydrogen. It's an exothermic reaction so you get a lot of heat, which can also be useful. Store some in phase change media.

 

Mars atmosphere is almost entirely carbon dioxide, so that's not a problem. 

 

Hydrogen can be had by electrolyzing water using solar arrays and/or any number of catalytic reactions. 

 

So, where to get water on Mars? 

 

1) use robot diggers to dig ice out of the thermofrost. This works where the ice is shallow, which it is over much of Mars. In nothern latitudes it's just under the surface.  Caterpillar has built several protypes of robotic miners for the Moon. Melt it with Sabatier reactor heat and electrolyze.

 

2) Mars atmosphere also contains water vapor, and at night in low elevations the humidity approaches 100%. It's not a lot, but just suck in the Martian atmosphere and pass it through zeolite beds. When they saturate, close the system and use some of the Sabatier reactors heat directly to distill out the water. Rinse, wash, repeat. Best to have many operating in parallel and phased for continuous output. Studies have shown this could be quite effective, and it's stone cold simple.

 

3) deeper ice could be drilled for and the phase change media's heat used for extraction. Once the hole is drilled extract the heat into a heat exchanger, using it to melt the ice for extraction and freezing in a container. Rinse, wash, repeat using many bots and use the Sabatier reactors heat at camp to melt it for electrolyzing.

 

4) some craters constantly show signs of melted brine running down their walls starting just below the rim. Exploit.

 

Edited by DocM
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Theory is great, but has anyone actually built these machines and tested that they do actually work as expected? Reliably? In Mars conditions, and at a size and weight that can be transported?

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That is exactly what this entire plan is still missing. it is nice to be able to ship off 100 people to Mars in a giant spaceship and they could probably live inside that same spaceship for a little while after arriving. But before the first people even set food on Mars we need a lot of machinery and tools on the ground and in working condition to!

 

I imagine a bunch of machines such as these should be sitting on the surface waiting for their operators to arrive:

stock-photo-track-type-bulldozer-machine

 

Machines such as these need to be adapted for operating in Mars conditions, it would mainly be the fluids that drive the pistons that need an overhaul for those temperatures I guess. But then again, you would also need to either make these machines remotely controllable (either from a base camp or by a suited up person walking alongside it). Having the option to climb into a cabin and operate the traditional could as well be a doable, however in the interest of 'KISS' I guess it is better not to go bother with pressurized cabins and life support systems and such.

 

I wonder if Caterpillar or any other manufacturers already have something production worthy that could be dropped on Mars. I suppose Antarctica would be nice testing environment for these machines :D

 

Anyway, these here is just one single example of equipment and machinery that needs to be adapted for Mars use. I'd love to discuss about other stuff that is required. Such as basic building material for the first habitats and buildings.

 

How would you build on the surface of Mars? Are foundations such as needed here on Earth required? Would be able to (semi easily) create iron (rebar) over there and concrete, etc?

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Well if you are going to send any kind of heavy machinery it has to be completely redesigned from the bottom up, in my opinion internal combustion engines would not make sense, because of the fuel and oxygen requirement and weight, better to run everything on electricity. Also everything made from steal has to be made from high strength composites to save on weight, otherwise it will take up far too much mass on the rocket. Perhaps it is better to go with smaller multi purpose machinery in the beginning, and build the larger machines when you have local production of steal, which I imagine would be something you would want up as soon as possible regardless.

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Some parts of these machines are basically made of steel because of the extreme stress and pressure that is being put on them, could the business end of that mover I posted above for example be of anything but steel? I somehow get the feeling that after the first couple of times you push a composite into the dirt and try to dig a hole it would just rip to sh*t or something. I hope I am wrong tho, but for this sort of extremely heavy duty work you cannot get around it.

 

You are right about stuff like engines tho, internal combustion on Mars is just a no-no, Elon better put some guys over at Tesla to work :D But yeah, a production facility for iron and steel is one of the first things you would want up and running on Mars. The sooner you can locally produce replacement parts the better.

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I have no idea how composites would work for this, but not everything necessarily has to be carbon composites, high strength alloys could probably also be used as a replacement for steel in cases where carbon composts are not ideal.
My point is that steal is mostly used because it is fairly cheap, and weight is not a problem here on earth, in some cases it might be very desirable for these kinds of machines. However when you send something to Mars the material cost becomes negligible compared to the launch cost so even if the dozer is 20 times as expensive with new materials, perhaps you save 100 times that due to the reduced mass (completely made up numbers). You can always load it with rocks or other ballast on Mars for weight.

I imagine the first many structures build on Mars could be made in such a way that dozers are not needed or at least could be replaced by smaller machines or manual labour until such a time one could be build locally.
Eventually of course heavy machinery has to be used on Mars one way or the other, but to me it seems that the first launches could make better use of their payload mass than sending a huge chunk of steel.

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5 hours ago, FloatingFatMan said:

Theory is great, but has anyone actually built these machines and tested that they do actually work as expected? Reliably? In Mars conditions, and at a size and weight that can be transported?

Sabatier reaction: 

 

CO2 + 4 H2 → CH4 + 2 H2O + heat

 

The catalyst is nickel, or ruthenium on analuminum oxide.

 

Sabatier reactors have been in use for a century, and they are a commercial off the shelf item. There's one on ISS for CO2 removal, so they're space qualified, but its methane gets dumped overboard. The waste water produced has obvious uses.

 

Zeolite beds are big time commercial and are used to dehumidify, in water purification, for gas separation, and several other chemical processes. Very well understood. 

 

A cargo ITS spacecraft can haul up to 450 metric tonnes of cargo to Mars a pop so up-mass is not much of an issue. The first to land will be a logistics flight with built-in Sabatier and water extraction methods & tanks.

 

Also: internal combustion engines in Mars could have uses, so much so that NADQ designed IC's for use on the Moon. Methane would be an easy conversion, and everyone forgets that carbon monoxide can also be used as a rocket fuel or for the production of other propellants or synthesizing petroleum products. Just convert the CO2 in the atmosphere.

 

 

Edited by DocM
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So, what you're saying is that there are enough gasses in the martian atmosphere to be able to produce the fuel without actual mining, at least at first?  What sort of production rate are we talking here? Has a fully operational Martian sabatier fuel plant been built and tested yet? If not, are SpaceX doing that or does someone else have it in hand?

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A large Sabatier reactor for Mars would need to be configured in certain ways, with a cryocooler for liquifying the methane and water storage, but the tech is known and scales well. On Earth they're used industrially, with Germany building a 6 megawatt unit in 2013 for fuelling vehicles.

 

In 2011 a small test unit was run for a week straight on a simulated Martian atmosphere with a 99%+ conversion rate and high purity. It produced 1 kg of liquid methane a day, and a much larger Mars unit would have 2 years to produce return fuel for the next flight. Sized for the task, a full sized reactor could be part of the cargo ITS ships systems. 

 

This is known science, its just that no one has previously had a rocket large enough to send one to Mars, but soon there will be Falcon Heavy, Vulcan, New Glenn and ITS. A Sabatier reactor testbed is one of the experiments for a precursor Red Dragon mission.

Edited by DocM
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5 hours ago, FloatingFatMan said:

If not, are SpaceX doing that or does someone else have it in hand?

SpaceX has said they are explicitly the vehicle, not the colonizers. But providing a cheap passage to Mars opens the door for others. Hell, even I'm considering sitting down with a couple engineer friends of mine and (for fun) brainstorming what would be necessary for a simple colony on Mars. Merely because if no one else wants to take the task, if I could get the right people together we have roughly 5-10 years to get a game plan going. I don't want this opportunity to be missed, of course there are many others who probably think like me with much more capital behind them.

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Our first Neowin ThinkTank was about that very topic. Lots of great Academic, Scientific and Industry links within to get "Feet Dusty". Feel free to grab any and all ideas you like from it.

 

:yes: 

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And anyone who thinks SpaceX set this course without the support and interest of third parties needs a rethink. More so now that they've started producing major hardware. 

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11 hours ago, Beittil said:

>

I  imagine a bunch of machines such as these should be sitting on the surface waiting for their operators to arrive:

stock-photo-track-type-bulldozer-machine

 

Caterpillar modified 2 Cat 287C Skid Steer Loaders for lunar use by NASA.  Something like that could do some serious regolith moving.

 

hqdefault.jpg

 

 

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8 hours ago, Emn1ty said:

SpaceX has said they are explicitly the vehicle, not the colonizers. But providing a cheap passage to Mars opens the door for others. Hell, even I'm considering sitting down with a couple engineer friends of mine and (for fun) brainstorming what would be necessary for a simple colony on Mars. Merely because if no one else wants to take the task, if I could get the right people together we have roughly 5-10 years to get a game plan going. I don't want this opportunity to be missed, of course there are many others who probably think like me with much more capital behind them.

I would consider refuelling to be part of the vehicle support services, and therefore come under SpaceX's purvue.

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7 hours ago, DocM said:

Caterpillar modified 2 Cat 287C Skid Steer Loaders for lunar use by NASA.  Something like that could do some serious regolith moving.

 

hqdefault.jpg

 

 

How about this?

 

scout.png

 

Whilst it IS from a game, the vehicles in it have actually been designed by JCB for heavy construction work on Mars. The one pictured above is just a smaller class.

 

https://www.jcbpioneer.com/

 

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7 hours ago, DocM said:

And anyone who thinks SpaceX set this course without the support and interest of third parties needs a rethink. More so now that they've started producing major hardware. 

I would dearly like to hear what news there is from such companies.  SpaceX getting us TO Mars is fantastic, but we need habitats and such to actually LIVE there!

 

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1 hour ago, FloatingFatMan said:

I would dearly like to hear what news there is from such companies.  SpaceX getting us TO Mars is fantastic, but we need habitats and such to actually LIVE there!

 

If there's new IP involved some partners may want to stay behind the scenes until the patents are filed. Way back when our group and a university were working on a condylar knee implant that was an issue.

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