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China launches new space station module.

And, after the initial investment (which will, indeed, be considerable) mining aka cutting up an asteroid will be far cheaper than digging massive holes on Earth for far meagre bounties.

You are joking of course. Digging relatively small holes on Earth produces fabulous wealth. That isn't going to go away any time soon.

This 'fabulous wealth' is peanuts - and I mean truly insignificant - by comparison with what you would obtain by merely cutting up the surface layer of an asteroid.

Read on wikipedia how much more even a small NEO contains - more than you could extract from the entire Earth!

Further - if we look at historical examples - the so-called sailing age of discovery - we see that humans don't go insane - or become suicidal/etc - after years living on uncomfortable, cramped ships, risking death every day by a random storm.

Yes, but a lot of them weren't very happy and a lot of them did die. A lot of them didn't volunteer and a lot of them had long term illnesses that shortened their lives. For every jolly jack tar you had ten miserable bastards.

Yes - but the fact remains, they performed admirably, proving that human beings are not so frail as to go insane if they can't see Earth out the window or if they're separated from society for years or etc.

Of course, the miners will be volunteers, with adequate salaries - I very much doubt there will be a shortage of them.

As to illnesses/etc - easily prevented with rudimentary hygiene, nowadays.

As to being comfortable - their quality of life (after the O’Neill colony is built) will probably be superior to the quality of life most humans enjoy today, on Earth.
It's worth noting that many humans live - and lived - in communities not larger - many smaller - than 100 people.
 
But, how would you get those there..except from Earth..or the Moon.. noting that for each Kg of matter brought up from the Earth you pay $20,000 to get it to geosynchronous orbit.

Getting stuff from earth's surface to GEO takes about 13 to 14 km/s. It is likely this delta V budget will require multi-stage expendables for some time to come. Expendable is another word for disposable. And very expensive disposable hardware is a major factor that keeps space transportation expensive.

Stages.jpg


for the Moon, one has the added costs of facilities and operation as well as huge start-up costs..

One could use the same argument to demonstrate it's better to cross rivers with ferries than build bridges.

One has to have an infrastructure built up to do anything one proposes, and it's simply not there yet..and wont be with current expendentures..

Presently about a third of NASA's budget is for human spaceflight. This is about 6 or 7 billion per year. Here are two lunar development proposals that could be done within those constraints:

Spudis and Lavoie's lunar return proposal.
Spudis and Lavois suggest the use of telerobots for the early stages of building luna infrastructure. After humans arrive, telerobots could be a force multiplier.

ULA's Commercially Based Lunar Architecture This document was written before the discovery of lunar ice deposits. So lunar ice ISRU wasn't considered. It would put in place propellant depots and LEO and EML2, though. And they note frequent delivery of propellant (a cheap commodity) would be an ideal market new commercial space players. A robust flight rate would allow commercial space to enjoy a economies of scale return on investment. This alone would decrease cost of space access.

Yes, propellant depots and lunar infrastructure would cost money. But 100 billion over 20 twenty years isn't cost prohibitive. And lunar supplied propellant depots at different locations would allow travel with smaller, simpler, reusable vehicles.

Again, here is the graphic showing lunar propellant and resources are much closer to LEO and EML1:

CislunarFuelDepot.jpg



Chemical rockets are simply impractical for long term space colonization.. period.

For a number of reasons establishing a base on the moon would be much cheaper than establishing a base on NEOs or Mars. This would be the case even if we magically developed space elevators or other science fiction transportation. The moon is a better target even if these science fiction vehicles came to pass.

But we're not developing NTRs or space elevators. Presently it looks like we're going to spend several hundred billion for flags and footprints on an NEO via the SLS chemical rocket. For the same amount we could build permanent infrastructure on the moon.

As a taxpayer I would support going to space to stay. At this point a permanent lunar base is doable. Permanent Mars or NEO bases are not.

If our human space flight program is flags and footprints, better to cut it completely and not waste the money on publicity stunts.
 
to go insane if they can't see Earth out the window

Uhuh. At what time in history was a workforce, that wasn't a prison workforce, not able to see Earth out of the window?

As to being comfortable - their quality of life (after the O’Neill colony is built) will probably be superior to the quality of life most humans enjoy today, on Earth.

Surely it would behove humanity to make all humans on Earth enjoy a good quality of life before investing most of the wealth of the planet on a few miners. Especially when automation would be far cheaper.
 
to go insane if they can't see Earth out the window

Uhuh. At what time in history was a workforce, that wasn't a prison workforce, not able to see Earth out of the window?

Now you are surely joking.
Every sailing ship crew could not see anything but a watery abyss beyond the ship.
A prison cell is comfortable by comparison. Also – again, as historically proven, prisoners don’t go insane, despite abject conditions, confinement, etc.

As to being comfortable - their quality of life (after the O’Neill colony is built) will probably be superior to the quality of life most humans enjoy today, on Earth.

Surely it would behove humanity to make all humans on Earth enjoy a good quality of life before investing most of the wealth of the planet on a few miners. Especially when automation would be far cheaper.
And how do you propose to improve the quality of life for all humans on earth?
No matter what you do on Earth, the resources will remain the same - scarce.

By mining asteroids, the wealth of humanity - the resources to which we will have access - will increase thousandfold - no, millionfold! That WILL increase the quality of life for all humans.

And - automation far cheaper? At present - and for the foreseeable future - automation is not even technologically possible.
Before you talk ‘cheap’, you should talk ‘possible’.
 
Wouldn't launch loops serve as “mass drivers” on Earth? They have the potential to decrease the cost for launching people and equipment from Earth too.

The mesosphere about 70 kilometers up is where most shooting stars burn up. The pressure there is about 1 millibar, 1/1000 that of sea level.

The Space Shuttle Columbia burned up at an altitude of 20 kilometers going a velocity of .8 km/sec. The pressure at that altitude is about 1/14 that of sea level.

Achieving orbital velocity (8 km/s) in the troposphere would be very bad. Even a fraction of orbital velocity on earth's surface would be very bad.

Rail guns, cannons, trebuchets, etc. are viable on airless worlds. But earth's atmosphere precludes their use down here.

(Googling launch loop...) The Wikipedia article mentions a structure 2000 km long at an altitude of 80 km. 80 km is well above the troposphere. But such a huge structure 80 km above earth's surface isn't plausible in the near future.
 
for the Moon, one has the added costs of facilities and operation as well as huge start-up costs..

One could use the same argument to demonstrate it's better to cross rivers with ferries than build bridges.
..and this analogy is flawed.


A bridge is one thing, you can build it and many people can use it immediately upon completion, but selling a Lunar base has always been hard, no matter what the nation as it's expensive and only a few will get to use it..

The only thing holding us back from a complete permanent manned presence in space is budget and political will..none of which we have at the present time.

So, vote for folks that support a Space Program that isn't about flagpoles in rocks but about building the infrastructure to support Luanr bases and eventual colonies on the Moon and Mars..If enough votes are registered in that way, it'll be easy for that Lunar base to be started up...
 
About NASA having more than a few competent engineers - show, don't tell.
During the last 30 years, their main accomplishment was to keep the shuttle operational - with a few disasters along the road, and by spending HUGE sums of money.
Nowadays, they're having trouble building a slightly better/larger Apollo (using shuttle parts/etc).
The fact that, after so many years worth of delays, they barely made progress - and the fact that they don't reach after Apollo's plans (which they should have) and just rebuild the thing - actually manages to lend credence to the conspiracy theories that said the moon landings were faked and the whole moon program, a sham.
HIGHLY UNIMPRESSIVE.
Contrast this with SpaceX.

Nowadays, everything seems to be difficult for Nasa.
Nasa says a problem is very difficult? I look for a second opinion.

Now this is just insulting to the NASA engineers. The problem with NASA has nothing to do with the engineers, It's the politics they have to deal with. I make most of the SpaceX posts on this board, you don't have to educate me about their accomplishments.

Saying NASA should rebuild Apollo just points to the lack of knowledge on the subject and history of NASA's new launcher.

If they say something is difficult, you can bet it is and engineers elsewhere will agree. Don't confuse politics with engineering.
 
(Googling launch loop...) The Wikipedia article mentions a structure 2000 km long at an altitude of 80 km. 80 km is well above the troposphere. But such a huge structure 80 km above earth's surface isn't plausible in the near future.

The “structure” is just the cable, it is kept aloft by the centrifugal force of the cable rotor which continuously moves inside the cable sheath. Still sounds too optimistic – we're talking about a 4000 km long iron tube that's 5 cm thick continuously moving at 14 km/s, but it's still not the same as a 80 km free-standing structure. I think the main issue is the enormous engineering challenge to make it work and not fall apart, otherwise we have the materials and the money to do it, and it sounds cheap in the context of space travel.
 
But, as said, there are convincing proposals. For example Skylon;

And there's Elon Musk's Grasshopper. Presently, I'm not giving Skylon or Grasshopper even odds.

and here's an old one - G O'Neill mentioned it in "the high frontier" - mass drivers 'floating' via balloons at a high altitude above Earth (if you read the full details from the book, it will sound a lot less silly).

What is the buoyancy of the balloons holding the mass driver aloft? What is the mass of the mass driver and payload?

Most of the high altitude balloons have walls thinner than Seran Wrap. Strapping massive structure to these walls would cause them to tear. Adding structure to make the balloons durable would further decrease buoyancy.

Balloons would have a huge cross sectional area which makes them vulnerable to being blown about by the wind.

This proposal is far less plausible than Skylon or Grasshopper RLVs.

I find your discussed objections regarding delta v and launch windows to Nereus not much of an impediment at all - as long as you travel to Nereus (or another NEO) to stay.

You'd send them on a three year tour of duty with zero experience mining in vacuum and microgravity. Sounds like a good reality show. Learn how to mine water and O2 within months, or you die!

This one way trip would be a suicide mission.

About 'mining experience' - this belongs to the category of eminently solvable obstacles that are considered game-stoppers (much like developing new space suits).

Solvable given enough time and money. Unfortunately these are finite. Unlimited budgets are a fantasy.

There will be unforseen surprises,

Indeed, unforeseen surprises frequently happen even in familiar terrestrial mining. Miners call this "Murphy's Law". They will happen much more frequently when we start attempting to mine completely alien ore bodies.

Unlike building AIs capable of autonomous mining

Straw man. I've been advocating telerobots, not autonomous AI. Telerobots are already being used by industry and their state of the art is improving.


Unless we are talking about astronomical amounts of chemical fuel (as per the rocket equation) situated at EML1 or EML2 or anywhere else (which, of course, require money to be put there), the launch windows towards Mars or an NEO or another human colony will be few and far between.

Delta V from earth to deep space body is typically 13 to 14 km/s. From LEO to a deep space body typically 3 to 4 km/s.

EML1 and EML2 have about a 2.4 km/s advantage over LEO.

Given a mere 1.2 km/s for Trans Mars Injection with a fully fueled and stocked ship, you have much wider launch windows and/or the option of shorter trip times.

From EML1, trans NEO injection can be be as low as .8 km/s.


As said - there's not enough energy in chemical fuels to create anything resembling easy interplanetary transport, anything resembling interplanetary trade.

Interplanetary trade is implausible because of the deep gravity wells. Better to get your resources locally.

Trade between asteroids is more plausible. But only if there is lunar and orbital infrastructure.

But, as said, there are convincing proposals. For example Skylon;

And there's Elon Musk's Grasshopper. Presently, I'm not giving Skylon or Grasshopper even odds.

and here's an old one - G O'Neill mentioned it in "the high frontier" - mass drivers 'floating' via balloons at a high altitude above Earth (if you read the full details from the book, it will sound a lot less silly).

Arguments without numbers is furious fan boy handwaving.

What is the buoyancy of the balloons holding the mass driver aloft? What is the mass of the mass driver and payload?

Most of the high altitude balloons have walls thinner than Seran Wrap. Strapping massive structure to these walls would cause them to tear. Adding structure to make the balloons durable would further decrease buoyancy.

Balloons would have a huge cross sectional area which makes them vulnerable to being blown about by the wind.

I find your discussed objections regarding delta v and launch windows to Nereus not much of an impediment at all - as long as you travel to Nereus (or another NEO) to stay.

You'd send them on a three year tour of duty with zero experience mining in vacuum and microgravity. Sounds like a good reality show. Learn how to mine water and O2 within months, or you die!

This one way trip would be a suicide mission.

About 'mining experience' - this belongs to the category of eminently solvable obstacles that are considered game-stoppers (much like developing new space suits).

Solvable given enough time and money. Unfortunately these are finite. Unlimited budgets are a fantasy.

There will be unforseen surprises,

Indeed, unforeseen surprises frequently happen even in familiar terrestrial mining. Miners call this "Murphy's Law". They will happen much more frequently when we start attempting to mine completely alien ore bodies.

Unlike building AIs capable of autonomous mining

Straw man. I've been advocating telerobots, not autonomous AI. Telerobots are already being used by industry and military. And their state of the art is improving.

Unless we are talking about astronomical amounts of chemical fuel (as per the rocket equation) situated at EML1 or EML2 or anywhere else (which, of course, require money to be put there), the launch windows towards Mars or an NEO or another human colony will be few and far between.

Delta V from earth to a deep space body is typically 13 to 14 km/s. From LEO to a deep space body typically 3 to 4 km/s.

EML1 and EML2 have about a 2.4 km/s advantage over LEO.

Given a mere 1.2 km/s for trans mars injection with a fully fueled and stocked ship, you have much wider launch windows and/or the option of shorter trip times.

From EML1, trans NEO injection can be be as low as .8 km/s.


Simple calculations prove it necessitates VERY long travel times and is capable of carrying VERY little mass at the interplanetary level.

Given a transfer orbit tangent to both earth and Mars orbit, Mars trip time can range from 210 days to 310 days.

Given a 130 tonne Mars Transfer Vehicle, a 7 to 10 month journey would be borderline suicidal. Very little mass for radiation shielding. And a failure of CO2 scrubber (such as the ISS suffered) could easily mean death.

However, given water, air and propellant at EML1, it is quite plausible to send a 250 tonne MTV Marsward. Extra radiation shielding and extra life support consumables makes an 8 month journey much less perilous.

Transfer orbits tangent to both earth's orbit and an eccentric NEO orbit are interesting. Here are some delta Vs for such orbits to asteroid 2009 OW6:

TanTransferDVs.jpg


Note earth Vinf at departure and asteroid Vinf at rendezvous add up to ~6.6 km/s for each transfer orbit. But a large earth Vinf can be helped a lot by the Oberth effect deep in earth's gravity well. It is the Oberth effect that makes aphelion rendezvous so cheap. From LEO, the distant rendezvous can be reached for as little 5.1 km/sec. But if you're willing to spend up to 6.2 km/s, trips less than two months occur occasionally. Given EML1's 2.4 km/s advantage, the 29.8 day trip would about 4.5 km/s.
 
Now you are surely joking.
Every sailing ship crew could not see anything but a watery abyss beyond the ship.
An abyss is a deep trench. What a sailing crew sees out its porthole, no matter what era, no matter if they're chained to the oars, it the Earth. More often than not, until recent history, the shore was almost always in sight and going ashore was frequent, to trade.

[And how do you propose to improve the quality of life for all humans on earth?
No matter what you do on Earth, the resources will remain the same - scarce.

Now you really are kidding. Earth resources are abundant. Far more abundant than anywhere else in this solar system and they have the beauty of being right here, without costing the Earth to get a few people out to the back of nowhere to prove something not very interesting.
 
..and this analogy is flawed.


A bridge is one thing, you can build it and many people can use it immediately upon completion, but selling a Lunar base has always been hard, no matter what the nation as it's expensive and only a few will get to use it..

A lunar base isn't the only possible consumer of lunar propellant.

This pdf estimates 700 tonnes of LEO propellant are burned each year boosting comsats from LEO to GEO.

Presently our sats are so difficult to reach that the paradigm is design, build, launch, discard. Routine transportation between earth orbits would make it cost effective to make modular satellites that are amenable to upgrade and repair.

And then there's orbital debris. A growing problem that must be addressed sooner or later. Deorbiting or collecting a dead sat entails matching velocity with it for rendezvous. Which would take a lot of propellant.

Establish propellant depots and reusable Orbital Transfer Vehicles and there would be many immediate applications.

The only thing holding us back from a complete permanent manned presence in space is budget and political will..none of which we have at the present time.

As mentioned, 100 billion over 20 years is doable with plausible budgets.

Politically, more space dollars are invested in providing jobs building HLVs. I believe Mike Griffin and many HLV advocates subscribe to Zubrin's fantasy of terraforming and colonizing Mars. Many space advocates still don't know about the CHON at the lunar poles, nor do they know of the delta V advantages EML1 and EML2 can confer.

So, vote for folks that support a Space Program that isn't about flagpoles in rocks but about building the infrastructure to support Luanr bases and eventual colonies on the Moon and Mars

I will do that.

..If enough votes are registered in that way, it'll be easy for that Lunar base to be started up...

Sadly, that's a big if. Space exploitation or settlement isn't even on the radar screen of most congressmen.
 
But, as said, there are convincing proposals. For example Skylon;

And there's Elon Musk's Grasshopper. Presently, I'm not giving Skylon or Grasshopper even odds.


Grasshopper is not intend to enter service. It's a research vehicle to test what can be done to make Falcon 9 re-usable. It's envelop of operation is not planned to go higher than 20,000 feet or so.

Skylon, unlike Falcon 9, is still a paper rocket, so yeah, I agree with you on the odds there.
 
About NASA having more than a few competent engineers - show, don't tell.
During the last 30 years, their main accomplishment was to keep the shuttle operational - with a few disasters along the road, and by spending HUGE sums of money.
Nowadays, they're having trouble building a slightly better/larger Apollo (using shuttle parts/etc).
The fact that, after so many years worth of delays, they barely made progress - and the fact that they don't reach after Apollo's plans (which they should have) and just rebuild the thing - actually manages to lend credence to the conspiracy theories that said the moon landings were faked and the whole moon program, a sham.
HIGHLY UNIMPRESSIVE.
Contrast this with SpaceX.

Nowadays, everything seems to be difficult for Nasa.
Nasa says a problem is very difficult? I look for a second opinion.

Now this is just insulting to the NASA engineers. The problem with NASA has nothing to do with the engineers, It's the politics they have to deal with. I make most of the SpaceX posts on this board, you don't have to educate me about their accomplishments.

If they say something is difficult, you can bet it is and engineers elsewhere will agree. Don't confuse politics with engineering.

Perhaps the politicians are the culprit, and not the engineers.
But Nasa is composed of both. If, as an unit, a team, it fails, pointing the finger at the politicians doen't really change anything in its efficiency as an agency.

Saying NASA should rebuild Apollo just points to the lack of knowledge on the subject and history of NASA's new launcher.
Apollo is far better than Nasa's new launcher by virtue of actually working, as opposed to being a pretty powerpoint presentation - 'paper rocket' - that 'will' - in some nebulose future - carry more to orbit.

So - what are the reasons for discarding Apollo, sojourner?
 
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Now you are surely joking.
Every sailing ship crew could not see anything but a watery abyss beyond the ship.
An abyss is a deep trench.

You've obviously never sailed before.


[And how do you propose to improve the quality of life for all humans on earth?
No matter what you do on Earth, the resources will remain the same - scarce.

Now you really are kidding. Earth resources are abundant. Far more abundant than anywhere else in this solar system and they have the beauty of being right here
And you obviously didn't read up on the resources present on NEOs and how they compare to what's accessible on Earth.

Or you're just being contrary.
 
Perhaps the politicians are the culprit, and not the engineers.
But Nasa is composed of both. If, as an unit, a team, it fails, pointing the finger at the politicians doen't really change anything in its efficiency as an agency.
Nope, stop. no moving the goalposts. We were talking about NASA's ability to rate the difficulty of building something in orbit. Not it's efficiency as an agency.
Apollo is far better than Nasa's new launcher by virtue of actually working, as opposed to being a pretty powerpoint presentation - 'paper rocket' - that 'will' - in some nebulose future - carry more to orbit.

So - what are the reasons for discarding Apollo, sojourner?
1) Saturn V hasn't flown in over 37 years. Saturn I in over 35 years.
2) a Saturn rocket hasn't been built in over 35 years.
3) The tooling for Saturn hasn't existed in over 30 years.
4) blame Nixon and Vietnam for the system (and it's failings) we got to replace it (STS)
5) the original plans do exist contrary to urban myth, but it would cost more (see number 3 above) to try and put it into production than to build SLS which at least makes use of STS factory tooling.

Saturn is more of a "paper rocket" today than SLS.
 
Perhaps the politicians are the culprit, and not the engineers.
But Nasa is composed of both. If, as an unit, a team, it fails, pointing the finger at the politicians doen't really change anything in its efficiency as an agency.
Nope, stop. no moving the goalposts. We were talking about NASA's ability to rate the difficulty of building something in orbit. Not it's efficiency as an agency.

In my post which started this line of conversation, I talked about Nasa's inefficiency in general - "During the last 30 years[...]".
You actually thought I only talked about welding in orbit in that post?

If so, you showed no sign of it: you responded by mentioning the possible cause of Nasa's inefficency - inefficiency which covers far more than welding in orbit, etc.

If there was any goalpost moving, you are the one who just did it, in the post to which I'm responding.

Apollo is far better than Nasa's new launcher by virtue of actually working, as opposed to being a pretty powerpoint presentation - 'paper rocket' - that 'will' - in some nebulose future - carry more to orbit.

So - what are the reasons for discarding Apollo, sojourner?
1) Saturn V hasn't flown in over 37 years. Saturn I in over 35 years.
2) a Saturn rocket hasn't been built in over 35 years.
3) The tooling for Saturn hasn't existed in over 30 years.
4) blame Nixon and Vietnam for the system (and it's failings) we got to replace it (STS)
5) the original plans do exist contrary to urban myth, but it would cost more (see number 3 above) to try and put it into production than to build SLS which at least makes use of STS factory tooling.

Saturn is more of a "paper rocket" today than SLS.
The fact that Saturn hasn't been built in 30+ years should be of little consequence as long as the complete plans are available.

I find surprising that you affirm reconstructing the tooling for Saturn (everything there known) would cost more than solving the problems needed for building SLS (which, apparently, won't be solved with the available budget or in the planned timeline).
What exactly makes the tooling for Saturn so expensive, sojourner?

An abyss is a deep trench.

You've obviously never sailed before.

You mean apart from being part owner of a Prout Snowgoose for 10 years?

Are you? Have you sailed with it?
Considering how you speak, one would not say so. Quite the contrary, actually.
 
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Are you? Have you sailed with it?
Considering how you speak, one would not say so. Quite the contrary, actually.

Because I disagree with you, I have a boat I've never sailed? How do you think you sound to everyone else in this thread?
 
Definition of abyss:
1. a deep, immeasurable space, gulf, or cavity; vast chasm.
2. anything profound, unfathomable, or infinite: the abyss of time.
3. (in ancient cosmogony)
a. the primal chaos before Creation.
b. the infernal regions; hell.
c. a subterranean ocean.
 
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