Blue Origin Thread (merged)

[YNM]

10 minutes ago, CatastrophicFailure said:

Any fledgling Mars colony would be regularly resupplied, too. That's where those hundreds of tons of cargo I've been mentioning come in. That's the point you guys seem to be missing. That's what makes it viable. The regular resupply while learning to live with what's there. We know people can live in semi-closed loops for more than two years like this.

... Then kepler is your enemy.

10 minutes ago, CatastrophicFailure said:

Look at the current political state of the world. Methinks this will be one of the very factors driving people to go there. 

Look at Republic of Minerva.

Edited October 1, 2016 by YNM

[Nibb31]

4 minutes ago, CatastrophicFailure said:

Any fledgling Mars colony would be regularly resupplied, too. That's where those hundreds of tons of cargo I've been mentioning come in. That's the point you guys seem to be missing. That's what makes it viable. The regular resupply while learning to live with what's there. We know people can live in semi-closed loops for more than two years like this. 

So it isn't self-sufficient after all.

4 minutes ago, CatastrophicFailure said:

Look at the current political state of the world. Methinks this will be one of the very factors driving people to go there. 

Not many people want to live in a complete anarchy, controlled by either corporations or thugs. No government also means no public service, no rights, no justice, no protection. You can't really have much of a society without at least some form of government.

[tater]

5 minutes ago, CatastrophicFailure said:

Any fledgling Mars colony would be regularly resupplied, too. That's where those hundreds of tons of cargo I've been mentioning come in. That's the point you guys seem to be missing. That's what makes it viable. The regular resupply while learning to live with what's there. We know people can live in semi-closed loops for more than two years like this. 

We understand this completely. The difference is the resupply rate.  There are about 10 resupply missions to ISS each year, and about 4 crew launches (presumably with some supplies). Cargo, varies between serval hundred kg, and 3 tons. Call it 20 tons a year for 6 people...

If something breaks that you didn't send beforehand, this matters.

[Nibb31]

49 minutes ago, Rakaydos said:

You dismiss SpaceX as a free enterprise without goverment backing on it's goals.

I don't dismiss anything. I'm just observing that SpaceX's settlement initiative isn't backed by any political, social, or economical movement or organisation. Building a colony on Mars doesn't even register in the list of things that people worry about. Have you heard one of the US presidential candidates adding it to their platform?

49 minutes ago, Rakaydos said:

https://www.bustle.com/articles/109479-elon-musks-net-worth-is-more-than-the-gdp-of-nicaragua-54-other-countries

After a certian point, a sufficently rich backer with a goal in mind can effectively BE the "goverment" backing it. He who has the Gold makes the Rules.

That's would be a dictatorship. Musk isn't keen on actually building a settlement himself, let alone governing it. I also don't think that a government where the head of state is also the local business mogul is very appropriate.

 

 

[Rakaydos]

Just now, Nibb31 said:

I don't dismiss anything. I'm just observing that SpaceX's settlement initiative isn't backed by any political, social, or economical movement or organisation. Building a colony on Mars doesn't even register in the list of things that people worry about. Have you heard one of the US presidential candidates adding it to their platform?

That's would be a dictatorship. Musk isn't keen on actually building a settlement himself, let alone governing it. I also don't think that a government where the head of state is also the local business mogul is very appropriate.

 

 

It's not the best option, but it is an option. Elon Musk is ideologically driven. He currently believes that simply making the rocket will lead to expansion happening, but if that fails, he's still got a slowly building fortune, and the same ideology. If the rocket doesnt solve the problem he wants solved, he'll start work on the next bottleneck, and the next, until he dies, changes his mind, goes unexpectedly bankrupt or has his mars colony.

[Exoscientist]

On 9/30/2016 at 11:24 AM, Nibb31 said:

No. He said it *might* be able to reach orbit, if you really really stripped it down, with no payload, and no return capability.

That is not in any way a useful SSTO capability. There are already plenty of rockets that can do that. Nobody does it, because it's pointless.

 Actually he said the tanker definitely could reach orbit, but couldn't return. I assume because it couldn't keep enough fuel on reserve. So it could be an expendable SSTO. How much payload that means as an expendable SSTO hasn't been given.

 

  Bob Clark

[Nibb31]

Stripped down means no payload. He's not building these things to make them expendable. They are twice the cost of an F9. 

[Technical Ben]

Why provide transport (ships) to the new lands? Why provide transport (railroads) in the new lands?

It was trade and materials.

What does Mars have it can trade?

Space? Earth has that. A lot more (physically it is larger and environmentally it has seas/ice sheets/deserts).

Materials? Earth has them. A lot more.

There is literally zero reason to go as an individual other than "because". Even as a group, only control/independence would be the drive. That is not a good enough reason IMO, go live in the north/south pole or the moon if you really want isolation.

22 hours ago, CatastrophicFailure said:

You die in space. You die at the South Pole. You die at the bottom of the sea, and plenty of other places hostile to human life we've learned to live at with regular resupply. That's really the fundamental goal of Musk's vision here, making all this routine and pridictable. 

You can live in some awful places with predictable resources. I'd say mars is actually easier to survive on long term than the South Pole, at least it's theoretically possible to be self-sufficient on Mars. 

Will the first ship carry 100 people? No, of course not. And it will find hundreds of tonnes of cargo and supplies waiting when it does bring those first 10 or 20 or whatever people. That's not the point of this endeavor. 

The point is that others will follow. That's what really makes a colony. 

Ok, so even though some of the land near the poles has accessible ground (for mining), excess oxygen (for breathing), unlimited water (for drinking) and you would only need power (for heat) and a hydroponics farm (for food)... you consider Mars a better candidate (minus the delta v budgets needed as we presume Elon is providing them for free)?

I need to ask myself why I am bothering to attempt to use logic of any form to educate in this argument here...

Edited October 1, 2016 by Technical Ben

[wumpus]

On 9/30/2016 at 1:38 PM, Aethon said:

NASA has some big tanks too.

Weld complete on the core stage hydrogen SLS tank.

http://www.nasa.gov/exploration/systems/sls/multimedia/welding-complete-on-fuel-tank-for-sls-rocket

I'm pretty sure that "big hydrogen tank" is redundant.  That stuff basically doesn't have a density.  Is the tank for the oxydizer 1/6th the size or even less?

[Bill Phil]

14 minutes ago, wumpus said:

I'm pretty sure that "big hydrogen tank" is redundant.  That stuff basically doesn't have a density.  Is the tank for the oxydizer 1/6th the size or even less?

https://www.google.com/search?q=external+tank+diagram&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjsir6mrrrPAhVB6yYKHTTVCVkQ_AUICCgB&biw=1280&bih=623

If you look at ET diagrams, the LOX tank is much, much, smaller.

[Vanamonde]

Mr. Musk seems to be concerning himself with the process of getting to Mars, and leaving the matters of survival there and governance to others. So that this thread doesn't become too much of a grab bag, why don't we follow his example? Please take the discussion of colonization to another thread, and leave politics for another forum altogether, since that never ends well here. 

(And yes, I realize I contributed to the clutter by merging some threads recently, but what can I say? Threads evolve.) 

Edit: like this one.

[CatastrophicFailure]

54 minutes ago, Technical Ben said:

I need to ask myself why I am bothering to attempt to use logic of any form to educate in this argument here...

Ad hominem? Ok, I'm done here then. 

The entire thing is completely speculation, so y'all pessimists can use anything you want to rationalize your pessimism. I will continue to be an optimist until there's a concrete, demonstrated reason to be otherwise.  

[Motokid600]

What about artificial gravity? Do they plan on getting the transit time whittled down so much it wont factor in? Iirc Musk was throwing around numbers as low as 30 days. How could such a thing be even possible with the current Raptor engines? Some kind of external tank extension? Dv would be off the charts.

[tater]

Given a travel time of 80-180 days, it might not matter that much. 

[Motokid600]

1 minute ago, tater said:

Given a travel time of 80-180 days, it might not matter that much. 

Is 80 days possible with the current design? Talking tens of thousands of m/s.That would take a bunch of ITS strapped together I suppose. Maybe even drop most of the engines.

[tater]

36 minutes ago, Motokid600 said:

Is 80 days possible with the current design? Talking tens of thousands of m/s.That would take a bunch of ITS strapped together I suppose. Maybe even drop most of the engines.

This is for a non-tangential transfer orbit to Mars (i.e.: not a Hohmann):

Note that the dv total includes insertion at Mars. Depending on what the allowable EDL parameters are (perhaps an aerobraking pass for capture?), it might be closer to the lowest energy case. 80 days is for 10km/s, but you can half the transit time with just a couple km/s.

Note that the above is for an average Mars separation.

 

Edited October 2, 2016 by tater

[tater]

Interesting link about total mission times:

http://www.csc.caltech.edu/talks/mazanek.pdf

Adding just a little dv makes a profound difference in travel times, however, assuming you can deal with the EDL at higher entry velocities. All tend to use that left part of the graph above (Hohmann upper left, basically). Low energy transfers can actually be as short as ~135 days depending on the geometry, apparently.

[Northstar1989]

5 hours ago, Technical Ben said:

Why provide transport (ships) to the new lands? Why provide transport (railroads) in the new lands?

It was trade and materials.

What does Mars have it can trade?

Space? Earth has that. A lot more (physically it is larger and environmentally it has seas/ice sheets/deserts).

Materials? Earth has them. A lot more.

There is literally zero reason to go as an individual other than "because". Even as a group, only control/independence would be the drive. That is not a good enough reason IMO, go live in the north/south pole or the moon if you really want isolation.

Ok, so even though some of the land near the poles has accessible ground (for mining), excess oxygen (for breathing), unlimited water (for drinking) and you would only need power (for heat) and a hydroponics farm (for food)... you consider Mars a better candidate (minus the delta v budgets needed as we presume Elon is providing them for free)?

I need to ask myself why I am bothering to attempt to use logic of any form to educate in this argument here...

The South Pole has the same problem as the Republic of Minerva- it's on Earth, so SOMEONE will try and enforce a claim on it if you seriously begin an effort to settle it...

Additionally, as I pointed out, it's actually a lot harder to keep warm on the South Pole than on Mars.  And huge drifts of snow and ice can cover solar panels and crush greenhouses.  I don't know why people keep insisting it would be easier to survive in the Antartic than on Mars- that's simply NOT true.  You require more heating, more insulation, and a lot more and more dangerous ourside maintenance just to keep the electricity running in the Antartic.  Just like Mars, unprotected exposure will very quickly kill you, but unlike Mars the atmosphere is dense enough for winds to pose a serious hazard (The Martian is unrealistic in this manner- the strongest winds on Mars hold less momentum than a light breeze on Earth...) and to covect all your heat away very quickly.  Compared to all that, the availability of free O2 is a relatively small boon.

Life on Mars would be more easily sustainable than life on Antartica.

 

Regards,

Northstar

[magnemoe]

31 minutes ago, tater said:

Interesting link about total mission times:

http://www.csc.caltech.edu/talks/mazanek.pdf

Adding just a little dv makes a profound difference in travel times, however, assuming you can deal with the EDL at higher entry velocities. All tend to use that left part of the graph above (Hohmann upper left, basically). Low energy transfers can actually be as short as ~135 days depending on the geometry, apparently.

Well known for experienced KSP players, try to lift Ap above Minmus orbit and the tip takes 5 days. However the dV cost goes up fast, an porkshop graph shows this well. 

[Northstar1989]

1 hour ago, magnemoe said:

Well known for experienced KSP players, try to lift Ap above Minmus orbit and the tip takes 5 days. However the dV cost goes up fast, an porkshop graph shows this well. 

Which is exactly why SpaceX needs to plan on sending their cargo seperately.  It can cost little over 3 km/s to get to Mars according to the chart posted earlier, and less with aerocapture (I thought the 3 km/s figure included aerocapture in its assumptions???) and lunar gravity-assists.  Plus, if the tankers really do end up being completely reusable and as cheap as Musk seems to antocipate, you could actually cost-effectively bring the Delta-V gap even further down by refueling cargo shipments in an elliptical or lunar orbit (or an elliptical lunar orbit!) before proceeding to Mars...

Since it takes 5.4 km/s just to get the upper stage in orbit, though, they will either need to re-design the booster to reduce the Delta-V requirements on the upper stage, or launch the cargo ships empty and only load them once they are in Low Earth Orbit to really get the most out of them with a slower trajectory... (the idea is to cram as much cargo into a single shipment as possible- until you bring the cargo-only ICT's Delta-V down to 4 or 5 km/s or less...)

 

Regards,

Northstar

Edited October 2, 2016 by Northstar1989

[todofwar]

My apologies if this has been talked about already but this thread moves fast. Looking at that BFR, just how much fuel will be needed to get it back to the launch pad? It will have to kill all forward momentum and then give itself enough momentum to go back to base. I always thought the first stage is supposed to provide almost as much dv in the horizontal as the vertical, so it either has to basically just get the second stage to altitude without providing much horizontal speed (blanking on the real term here) or it needs to reserve almost the same amount of fuel for the trip back as the trip up. 

[CatastrophicFailure]

5 minutes ago, todofwar said:

My apologies if this has been talked about already but this thread moves fast. Looking at that BFR, just how much fuel will be needed to get it back to the launch pad? It will have to kill all forward momentum and then give itself enough momentum to go back to base. I always thought the first stage is supposed to provide almost as much dv in the horizontal as the vertical, so it either has to basically just get the second stage to altitude without providing much horizontal speed (blanking on the real term here) or it needs to reserve almost the same amount of fuel for the trip back as the trip up. 

Musk's estimate from the video is they'll have to keep 7% of the propellant in reserve for RTL. Remember, once all that upper stage mass is gone, a little fuel goes a long way.  

[kerbiloid]

Meanwhile...

https://www.washingtonpost.com/business/economy/implication-of-sabotage-adds-intrigue-to-spacex-investigation/2016/09/30/5bb60514-874c-11e6-a3ef-f35afb41797f_story.html?hpid=hp_hp-more-top-stories_spacex-738am%3Ahomepage%2Fstory

Edited October 2, 2016 by kerbiloid

[Nothalogh]

1 hour ago, kerbiloid said:

Meanwhile...

https://www.washingtonpost.com/business/economy/implication-of-sabotage-adds-intrigue-to-spacex-investigation/2016/09/30/5bb60514-874c-11e6-a3ef-f35afb41797f_story.html?hpid=hp_hp-more-top-stories_spacex-738am%3Ahomepage%2Fstory

1 mile, line of sight.

That's intredasting

[Exoscientist]

13 hours ago, Nibb31 said:

Stripped down means no payload. He's not building these things to make them expendable. They are twice the cost of an F9. 

 He was talking about two different things the tanker and the space ship. The spaceship would have to be stripped down because it contains the quite large crew quarters integral to the spaceship. Note also it has larger dry mass and reduced propellant load, which means worse mass ratio and delta-v.

     Bob Clark