Blue Origin Thread (merged)

[TheEpicSquared]

Didn't they say November?

[kurja]

1 hour ago, kunok said:

The only advantage that I can see about 3d printing in this scenario is that you need less skilled workers

Except for the platoon of engineers you'd need to run and maintain our hypothetical orbital rocket-size printer. And the machinists who would have finish and inspect the prints. And and and.

[Elthy]

2 hours ago, kerbiloid said:

So, as you all can see, 3d printing (or additive manufacturing, doesnt matter) is just the key thing for Martian plans.

If they build a self-sustaining Martian colony, will they send a whole metallurgical plant (plants, as iron and aluminium production use rather different technologies), or will the colony need a high-quality industrial printer?
Bother with landing tin cans or just make them cheap expendables in the same way?

As you can see, a good 3d printing is a much more actual to colonize Mars rather than rocket equilibristics.

You are talking about 2 different things here, one is manufacturing on Mars (where 3D printing could be usefull for some things) an building the rockets/spaceships (where 3D printing could be usefull fpr a few parts). Also "cheap expendables" is a contradiction in itself.

The needed abilitys for a spacecraft to get from LEO to mars surface (powered landing, heatshield, high deltav...) are very similar to those needed to get back to earth surface. It seems quite stupid to not reuse them, on mars they are mostly useless chunks of metall/carbon.

[Mitchz95]

 

[kerbiloid]

4 hours ago, kunok said:

Is easier and require less machinery to cast the metal than to 3d print it.

On the Earth where you already have whole industry, Open the sortament reference and count how many thousands of metal products one should roll and cut.
On the Earth it's not a problem, as anything they produce, somebody will sooner or later buy. At least to melt. But when they need, say 1 t of bolts, 1 t of nuts, 2 t of 3 mm wire, 1 t of 4 mm wire, 3 t of tin scrolls, etc, should they build 100 metal rolling facilities each 100 times heavier than its total production?

Casting is not appropriate everywhere, because of dislocations and other defects. In fact, cast iron is used for brutal heavy dummy things, all more or less accurate goods are being cut from the rolled metal.

2 hours ago, Elthy said:

You are talking about 2 different things here, one is manufacturing on Mars (where 3D printing could be usefull for some things) an building the rockets/spaceships (where 3D printing could be usefull fpr a few parts). Also "cheap expendables" is a contradiction in itself.

No, I'm talking about the same thing. A skeleton key for both doors.

[Elthy]

Its not the same since the spaceships are build on Earth, where 3D printers are more expensive for most things.

[Tullius]

1 hour ago, kerbiloid said:

On the Earth where you already have whole industry, Open the sortament reference and count how many thousands of metal products one should roll and cut.
On the Earth it's not a problem, as anything they produce, somebody will sooner or later buy. At least to melt. But when they need, say 1 t of bolts, 1 t of nuts, 2 t of 3 mm wire, 1 t of 4 mm wire, 3 t of tin scrolls, etc, should they build 100 metal rolling facilities each 100 times heavier than its total production?

Casting is not appropriate everywhere, because of dislocations and other defects. In fact, cast iron is used for brutal heavy dummy things, all more or less accurate goods are being cut from the rolled metal.

No, I'm talking about the same thing. A skeleton key for both doors.

The precision and quality of casting are not the problem. Just look at the church bells, they are all cast and yet sound perfectly, despite small errors risking to be clearly heard.

The problem with casting iron is that it is much less strong than if it where rolled and then cut into the right shape. And since for 3D printing, the metal would need to be liquid, you will only get at best the quality of cast metal, but never the quality if it were rolled or forged.

Welding the tanks of a rocket allows you to use rolled sheets of metal and therefore to build lighter tanks, since the structural strength of rolled metal is so much better. On Earth, 3D printing is just an option for very difficult forms and prototypes, while there exist a lot of methods to produce stuff cheaper, faster or of higher quality than any 3D printer could ever do.

On the other hand, if you are on Mars, a 3D printer might come in handy, if you notice that you have missed something. Just think of Apollo 13, where they had to improvise an adapter to use the CMs CO2 scrubbers in the LM. With a 3D printer, they just could have printed an adapter, designed by the engineers on Earth. That is also why NASA is exploring 3D printing on ISS: They want to use it to print all those little things that you might have forgot to bring up with you. A 3D printed screwdriver might be of worse quality than a normal one, but at least you have one.

Edited October 27, 2016 by Tullius

[Northstar1989]

7 hours ago, kunok said:

3d printing is just a fancy new name to the additive manufacturing, a concept somewhat old. Also 3d printing is not used usually in some of the additive manufacturing techs, I think is because they aren't mean to the average Joe, they are restricted to the industry.

I'm not sure what are we talking about.

Is easier and require less machinery to cast the metal than to 3d print it.

When you have the liquid metal you can use it directly in a mold made by mars sand (you will need to look for a good one and sieve it), which can be done handmade with basic tools. To 3d print it you need to transform the liquid metal in something usable, that can be powder, wire, or whatever it uses.

So:

-For casting you only need producing the liquid alloy itself.

-For 3d printing you need to produce the liquid alloy, use a machine to made the consumables of the 3d printer, and then you need to use a 3d printer to make whatever. That's two more machines, consuming more time, resources (specially electricity) for a comparable final quality.

The only advantage that I can see about 3d printing in this scenario is that you need less skilled workers

Casting is not a usable method for producing modern rocket fuel tanks, actually.  It's not precise enough.  The *only* way we can currently produce fuel tanks to needed technical specifications is through reductive manufacturing (where you take a plate and machine it down).  SpaceX managed to reduce the amount of machining a bit by adding reinforcing "ribs" to their tanks, but it's still the only way to make a rocket fuel tank.

Certainly if 3D printing technology *vastly* improved in terms of speed, accuracy, and the strength of the manufactured products over the next 3 or 4 decades it might become an economical way to produce rockets, perhaps even expendable ones that could compete on a cost-basis with reusables.  But that level of refinement of the technology is AT LEAST 40 years away, and like cost-effective fusion power, might *never* materialize.  Musk is working within the realm of what's possible today and tomorrow, not what *might* be feasible in 40 years...

1 hour ago, Tullius said:

The precision and quality of casting are not the problem. Just look at the church bells, they are all cast and yet sound perfectly, despite small errors risking to be heard.

Church bells are hardly high-precision components.  Casting is, as an undisputable fact, NOT accurate enough for rocket parts- which need to be produced to insanely high precision due to the very narrow engineering margins on a modetn rocket...

(Narrow engineerong margins are the main reason rockets are currently so expensive- in fact the whole principle behind Big Dumb Boosters was to produce a rocket with much more generous engineering margins, so that the rocket could be manufactured much more cheaply.  BDB's would *NOT* be any less reliable than conventional rockets, but they would have *much* lower payload-fractions- which is why Musk thinks they're a bad idea.  Smart rockets make better reusable rockets, as they amortize their much higher manufacturing costs over many launches, and they have a clear payload size advantage over comparably sized Big Dumb Boosters, making them cheaper in the long run...)

 

Regards,

Northstar

P.S.  If Musk and SpaceX fail to obtain promised low costs for re-using their Falcon rockets, I really do hope they'll switch to Big Dumb Boosters.  Like it or not (Nibb, we all know your opinions on this subject, and you're wrong.  But please don't derail this discussion by starting  arguments about Big Dumb Boosters) BDB's are the next-best thing if you can't develop affordable reusables...

Edited October 27, 2016 by Northstar1989

[kunok]

I'm a manufacturing engineer, and

3 minutes ago, Northstar1989 said:

reductive manufacturing

please is subtractive manufacturing if you want to use this kind of expression and nobody uses that, is just plain machining. And we also do tanks by forming metal (not sure of the term in english, not my field) and with composites.

There is high quality casting (injection casting for example) and there is low quality 3d printing. They have a huge set of common disadvantages, about metal structure and precision.

2 hours ago, kerbiloid said:

Casting is not appropriate everywhere, because of dislocations and other defects. In fact, cast iron is used for brutal heavy dummy things, all more or less accurate goods are being cut from the rolled metal.

Hey, I'm trying to simplify things to the average Joe, and this is not in my language, of course you are right, but is not like there isn't that kind of defects in metal additive manufacturing.

Give me a good CNC 5axis lathe, milling machine, and cylindrical grinder and I will change the world. But then I will also need a lamination factory to get the metals as you said

[Northstar1989]

On Tuesday, October 25, 2016 at 5:14 AM, kunok said:

If only we had a minor body close to earth, relatively easy and fast to reach with low gravity, like some natural satellite

Colonization without doing any biological research is absurd, if only for the huge cost of making the first settlement in mars, to then discover that (for example) humans body develops illness at an exponential rate in low or no gravity, an effect that we still didn't see because it gets perceptible when you goes 2 years in low gravity.

We only have full data of 1g, and a little (the longest stay in space was Valeri Polyakov, 437 days in the MIR) in 0g. Nothing in between, nothing at longer times

Lunar gravity isn't high enough for normal human health.  Liquids settle too slowly on the Moon,  we already know that.  There's a BIG difference between lunar gravity (0.16 g), and Mars gravity (0.38 g).  Mars gravity is more than 2x as strong!  In fact Mars gravity is probably about the *bare minimum* necessary for (relatively) reasonable human health over a lifetime spent off-planet (i.e. I doubt lunar colonies will ever be a thing- the gravity is just too low).

Don't get me wrong, Mars gravity is likely to cause some health problems.  A higher risk of kidney stones and kidney failure, severe constipation, and osteoporosis mainly.  But the increase in incidence of these diseases shouldn't be nearly bad enough to make colonization unfeasible, though they'll probably replace obesity, heart disease/stroke (the two are actually closely related, and bad cholesterol is a huge risk factor for both as it leads to clot-formation), and diabetes as the main public health menaces on Mars... (because food will be very limited on Mars- so people won't be able to literally eat themselves to death like on Earth).

Early Mars colonists will probably be limited to a mostly-vegetarian, vegetable and cereal-rich diet.  The main sources of animal protein will probably be silkworms and snails... (I know they don't sound appealing, but the Chinese/French eat them!) And when they eventually bring over the first mammals, they will be used entirely for milk production (as it's more calorie-efficient than meat-production).

 

Regards,

Northstar

Edited October 27, 2016 by Northstar1989

[tater]

2 minutes ago, Northstar1989 said:

Lunar gravity isn't high enough for normal human health.  Liquids settle too slowly on the Moon,  we already know that.  There's a BIG difference between lunar gravity (0.16 g), and Mars gravity (0.38 g).  Mars gravity is more than 2x as strong!  In fact Mars gravity is probably about the *bare minimum* necessary for (relatively) reasonable human health.

We know neither of those things very well.

Staying on the topic of ITS (because SpaceX). Even an unmanned mission requires BFR, ITS, and Tanker to all exist. The life support systems would require stress tests (i.e.: with occupants actually messing the place up with their breath, waste, etc), and duration tests to characterize what tends to need replacing/fixing, and how often (ISS is constantly resupplied in this regard). 

So I'd orbit a tanker and an ITS loaded for a crew of X for a whole mission duration, then tether them and make a bolo and characterize things better. I might include mammals that could be raised/bred aboard (puppies---everyone needs a space dog, and there will be 0.38 g).

2 minutes ago, Northstar1989 said:

Don't get me wrong, Mars gravity is likely to cause some health problems.  A higher risk of kidney stones and kidney failure, constipation,  and osteoporosis mainly.  But the increase in incidence of these diseases shouldn't be nearly bad enough to make colonization unfeasible, though they'll probably replace obesity, heart disease, and diabetes as the main public health menaces on Mars...

Say 0.38g is enough to mitigate bone loss. Great. So those of us with "earth bones" will keep them. What about people raised on Mars? They might not constantly lose bone, but would;t their bone growth possibly arrest at some point, since it is simply unneeded? What are the implications? I personally have no idea, but it might be useful to find out before stranding people there (100 outbound, but only 20 can return, right?).

[Northstar1989]

Actually, we do know enough about lunar gravity to reasonably predict it would be disastrous for human health.

People born and raised on Mars, by contrast (babies who left at an early age would have few problems) would probably have a very difficult, even impossible time, living a normal life on Earth unless they engaged in some *very* intensive weight-training from an extremely early age.  Most simply wouldn't be able to return.  The extreme bodybuilders of Mars might be ultra-lightweight boxers by Earth standards.  But typical bone and muscle development for non-athletes would be enough to live a normal, healthy life on Mars, which is all that really matters...

Also, I didn't say people with Earth bones would keep them.  Over time bones and muscles would partially-atrophy and stabilize at a level that would be reasonable for Mars life, but very problematic for returning to Earth. The only way to avoid this would be frequent and intensive weight-training on Mars...

 

Regards,

Northstar

Edited October 27, 2016 by Northstar1989

[Nibb31]

9 hours ago, Northstar1989 said:

Actually, we do know enough about lunar gravity to reasonably predict it would be disastrous for human health.

Again, we know absolutely zero about partial gravity. I really don't know where you're pulling these claims from.

9 hours ago, Northstar1989 said:

People born and raised on Mars, by contrast (babies who left at an early age would have few problems) would probably have a very difficult, even impossible time, living a normal life on Earth unless they engaged in some *very* intensive weight-training from an extremely early age.  Most simply wouldn't be able to return.  The extreme bodybuilders of Mars might be ultra-lightweight boxers by Earth standards.  But typical bone and muscle development for non-athletes would be enough to live a normal, healthy life on Mars, which is all that really matters...

Also, I didn't say people with Earth bones would keep them.  Over time bones and muscles would partially-atrophy and stabilize at a level that would be reasonable for Mars life, but very problematic for returning to Earth. The only way to avoid this would be frequent and intensive weight-training on Mars...

Pure conjecture. It might be an educated guess, but it's still complete guesswork.

[tater]

22 hours ago, Northstar1989 said:

Actually, we do know enough about lunar gravity to reasonably predict it would be disastrous for human health.

The longest durations on the Moon were 3 days. That's effectively zero data given that they took very limited health data during that infinitesimal time period.

Guesstimates are fine, but don't characterize them as anything more than the guesses they are.

 

Edited October 28, 2016 by tater

[tater]

http://www.spacex.com/news/2016/09/01/anomaly-updates

Quote

Through extensive testing in Texas, SpaceX has shown that it can re-create a COPV failure entirely through helium loading conditions. These conditions are mainly affected by the temperature and pressure of the helium being loaded.

 

Edited October 29, 2016 by tater

[Bill Phil]

On ‎10‎/‎27‎/‎2016 at 3:15 PM, Northstar1989 said:

The only way to avoid this would be frequent and intensive weight-training on Mars...

Or  build cities that are giant centrifuges... Awfully complex and hard to do, of course. But it might be the best way to live on Mars. Either that or centrifuge therapy. Maybe if they sleep and work out in a 1g environment (and maybe born in one? Centrifuge hospitals?) they could come back to Earth and have an experience similar to an Astronaut who's been in orbit for a few months. Some adjusting would be necessary, but they could actually start that phase on the way, by spinning the ship to simulate 1g.

[magnemoe]

On 27.10.2016 at 9:15 PM, Northstar1989 said:

Casting is not a usable method for producing modern rocket fuel tanks, actually.  It's not precise enough.  The *only* way we can currently produce fuel tanks to needed technical specifications is through reductive manufacturing (where you take a plate and machine it down).  SpaceX managed to reduce the amount of machining a bit by adding reinforcing "ribs" to their tanks, but it's still the only way to make a rocket fuel tank.

Certainly if 3D printing technology *vastly* improved in terms of speed, accuracy, and the strength of the manufactured products over the next 3 or 4 decades it might become an economical way to produce rockets, perhaps even expendable ones that could compete on a cost-basis with reusables.  But that level of refinement of the technology is AT LEAST 40 years away, and like cost-effective fusion power, might *never* materialize.  Musk is working within the realm of what's possible today and tomorrow, not what *might* be feasible in 40 years...

Church bells are hardly high-precision components.  Casting is, as an undisputable fact, NOT accurate enough for rocket parts- which need to be produced to insanely high precision due to the very narrow engineering margins on a modetn rocket...

(Narrow engineerong margins are the main reason rockets are currently so expensive- in fact the whole principle behind Big Dumb Boosters was to produce a rocket with much more generous engineering margins, so that the rocket could be manufactured much more cheaply.  BDB's would *NOT* be any less reliable than conventional rockets, but they would have *much* lower payload-fractions- which is why Musk thinks they're a bad idea.  Smart rockets make better reusable rockets, as they amortize their much higher manufacturing costs over many launches, and they have a clear payload size advantage over comparably sized Big Dumb Boosters, making them cheaper in the long run...)

 

Regards,

Northstar

P.S.  If Musk and SpaceX fail to obtain promised low costs for re-using their Falcon rockets, I really do hope they'll switch to Big Dumb Boosters.  Like it or not (Nibb, we all know your opinions on this subject, and you're wrong.  But please don't derail this discussion by starting  arguments about Big Dumb Boosters) BDB's are the next-best thing if you can't develop affordable reusables...

Rocket fuel tanks need to be light, leakproof and strong, mostly make of rolled plates. You want internal structural plates to increase strength and avoiding sloshing. 

On place I see 3d printing as nice would be the injector plate, it has an complex internal structure, the other option is casting and high quality 3d print would be better here. 
Casting is always used for complex internal structures like engine blocks who need cooling an oil channels inside the block. You would need to use lathes on the cylinders and you also use inserts here for increased strength and making it an replaceable part. 
the injector plate is far more complex and you want more accuracy than the cooling channels in an car engine. 

[HebaruSan]

6 hours ago, Bill Phil said:

Maybe if they sleep and work out in a 1g environment (and maybe born in one? Centrifuge hospitals?) they could come back to Earth and have an experience similar to an Astronaut who's been in orbit for a few months.

Do they really need to be able to return to Earth if it turns out they can live healthily on Mars with less bone mass? Granted, it would be necessary in the "repopulate with a back-up population" scenario, but it's very unlikely that any colonist will have to do that.

[StrandedonEarth]

10 hours ago, tater said:

http://www.spacex.com/news/2016/09/01/anomaly-updates

 

I'm glad to hear that they're closing in on a probable cause. They've learned an expensive lesson about not experimenting with loading procedures with a customer's payload on top.

[Nibb31]

11 hours ago, HebaruSan said:

Do they really need to be able to return to Earth if it turns out they can live healthily on Mars with less bone mass? Granted, it would be necessary in the "repopulate with a back-up population" scenario, but it's very unlikely that any colonist will have to do that.

The "backup population" scenario is only (flawed) rationale than space cadets use to justify colonization. If Martians can't return to Earth, the whole plan falls apart.

[Northstar1989]

11 hours ago, HebaruSan said:

Do they really need to be able to return to Earth if it turns out they can live healthily on Mars with less bone mass? Granted, it would be necessary in the "repopulate with a back-up population" scenario, but it's very unlikely that any colonist will have to do that.

The ability to exchange top talent (engineers, scientists, etc.) between Mars and Earth would be useful in the long run, though it's certainly not necessary for a Mars colony to survive and grow.  Ultimately thete are much bigger challenges/concerns to populating Mars than the gravity- like the fact everything has to be in an leakproof pressure vessel, and those tend to suffer fatigue and rupture over time...

 

Regards,

Northstar

[Nibb31]

1 minute ago, Northstar1989 said:

The ability to exchange top talent (engineers, scientists, etc.) between Mars and Earth would be useful in the long run, though it's certainly not necessary for a Mars colony to survive and grow.  Ultimately thete are much bigger challenges/concerns to populating Mars than the gravity- like the fact everything has to be in an leakproof pressure vessel, and those tend to suffer fatigue and rupture over time...

Pretty much all of the vital equipment is similar in that regard. Designing and running machines in a near vacuum, extreme cold, environment with low maintenance, is going to require a huge engineering effort. You can't just buy an off-the-shelf Caterpillar or A/C unit and adapt it to Mars conditions. The problem is that nobody has any plans to invest an R&D effort into those things, including habitation pressure vessels. Without life support, mining equipment, ISRU generators, habs, and so on, a colony is non-starter.

Also, that toxic dust and will get everywhere.

 

[tater]

1 hour ago, Nibb31 said:

The "backup population" scenario is only (flawed) rationale than space cadets use to justify colonization. If Martians can't return to Earth, the whole plan falls apart.

Not really. It's just backing up humanity, not humanity on Earth. This is way off topic for this thread, as it is fundamentally a philosophical issue. Does future human wellbeing have value? Ie: if everyone could with no suffering cease to exist, is anything lost? If you think that meaningful (to the humans in question) existence has any non-zero value, then a sustainable Mars population has value, and if such value on Earth decreases below this net value (even if it's only of minimal value), then it's a win.

I happen to think Mars is not the best solution to this, however, I'm more in the Gerry O'Neill camp, I suppose. On topic, Musk is clearly more in the Mars camp... dunno where Bezos is.

You could argue that it's not how money should be spent, as other issues that impact humanity can be far more cost effectively addressed, that's also fine---but it's also not our money in this case. If some billionaires want to colonize Mars, more power to them, it has zero effect on my life, and I have no right to tell anyone how to spend their own money.

[Northstar1989]

1 hour ago, tater said:

I happen to think Mars is not the best solution to this, however, I'm more in the Gerry O'Neill camp, I suppose. On topic, Musk is clearly more in the Mars camp... dunno where Bezos is.

You could argue that it's not how money should be spent, as other issues that impact humanity can be far more cost effectively addressed, that's also fine---but it's also not our money in this case. If some billionaires want to colonize Mars, more power to them, it has zero effect on my life, and I have no right to tell anyone how to spend their own money.

As Musk has stated many times, a Mars colony would act as a forcing function for cheaper space travel and access to LEO.

Once humans are flying to Mars every year, things like the SKYLON program (the UK's plan for a fully reusable spaceplane, using cutting-edge hydrogen-oxygen hybrid jet/rocket technology), Mass Driver launch systems, Microwave Beamed Power (initially as a power-source for ultra high-ISP one-way Mars injections, like for cargo missions to supplement the ITS structure), Propulsive Fluid Accumulators (which could be powered by nuclear reactors,or Microwave Beamed Power), reusable nuclear space-tugs, asteroid-mining, and perhaps even fusion reactors for space propulsion or futuristic materials for a Space Elevator will all become much more worthwhile endeavors...

And, all this economic activity is CERTAIN to have an impact on your life.  The biggest problem with economies in developed nations right now is that they aren't really the subject of any substantial capital investments that grow their economies- most new factories are built in places like China.  Space Exploration, on the other hand, requires a highly skilled workforce and is far, far less likely to be outsourced to China...

 

Regards,

Northstar

Edited October 29, 2016 by Northstar1989

[tater]

9 minutes ago, Northstar1989 said:

As Musk has stated many times, a Mars colony would act as a forcing function for cheaper space travel and access to LEO.

Except there is no RoI on going to Mars, so it requires vast sums to be poured down a hole (Mars) that could just as well be spent making LEO travel cheaper from the start. 

9 minutes ago, Northstar1989 said:

Once humans are flying to Mars every year, things like the SKYLON program (the UK's plan for a fully reusable spaceplane, using cutting-edge hydrogen-oxygen hybrid jet/rocket technology), Mass Driver launch systems, Microwave Beamed Power (initially as a power-source for ultra high-ISP one-way Mars injections, like for cargo missions to supplement the ITS structure), Propulsive Fluid Accumulators (which could be powered by nuclear reactors,or Microwave Beamed Power), reusable nuclear space-tugs, asteroid-mining, and perhaps even fusion reactors for space propulsion or futuristic materials for a Space Elevator will all become much more worthwhile endeavors...

Skylon guestimates have it barely competitive with F9.  The other stuff... why not just spend billions on that instead of lighting money on fire WRT Mars as some sort of driver?

9 minutes ago, Northstar1989 said:

And, all this economic activity is CERTAIN to have an impact on your life.  The biggest problem with economies in developed nations right now is that they aren't really the subject of any substantial capital investments that grow their economies- most new factories are built in places like China.  Space Exploration, on the other hand, requires a highly skilled workforce and is far, far less likely to be outsourced to China...

Reread what I wrote in context. It was meant as a comment about any counter-argument that somehow humans should spend money to "save humanity" in a more effective way. It's their (Musk/Bezos) money, if their "save humanity" notion is Mars, it has no impact on me at all, who I am I to say they should spend it on some other pet project to save humanity---they can spend it the same way Bender would, for all I care.

I'm all for the billionaire space race, but the idea that Mars is economically feasible is pretty comical. Bezos has a better business model, IMO, the tourism market is just a matter of cost when it comes down to it. Like most things, it's just a matter of price. We spend 10s of thousands on a vacation, for example (direct costs for travel someplace like Europe for 4 people, plus opportunity costs (lost income))---but a few hundred grand is out of the question. If a week in orbit was ever on the same order of magnitude as a week on the other side of the Earth... where do I buy my tickets?