China launches new space station module.

[Edit_XYZ]

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?

You give the strong impression that you have a boat you never sailed because of how you refer to the ocean, not because you disagree with me.

You obviously feel the need to bicker about something.
Well, I have no interest in such a conversation.
This means we'll have to agree to disagree - on whatever you want to bicker about in your next post.

 

[YellowSubmarine]

I agree with the point though: Humans have been through tough shit and in ridiculously unnatural situations, and made it fine through all of them, even if slightly dead sometimes. All comparisons will be bad, because space and isolation in space is quite unlike anything we've been through, but that's all that we have.

Being right in the middle of the Pacific in a medieval ship, in worsening weather, with nothing but ocean around you for weeks, while everything there reminds you how far from the continents you are... That must be a hell of a situation, one that bears resemblance to the isolation of a colony far from Earth's orbit. And being through previous sailing troubles will make you see the sea with different eyes, perhaps make it much more alien than it seems at first. I dunno, deep space even seems more tolerable to me.

 

[Edit_XYZ]

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.

There's also the metaphorical use of the term, in order to make a point.

If you want to be literally-minded, you can go with meaning no 1. ~vast chasm or 2. ~anything profound.

During history - and even today - the depths of the planetary ocean were/are largely inaccessible and unknown.

 

[Deckerd]

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.

Uhuh and which abyss would you be looking at out the porthole of a ship? Just asking, like, since all I ever saw was sealife and waves. And weather. In UK waters at least you never see much below 2 meters no matter what the depth, so you could be over a trench or in 3 meters.

 

[YellowSubmarine]

By that same line of thinking, from the window of your colony you just see the night sky on all sides. Nothing particularly interesting.

Thing is, some of us imagine the unknown depths of the ocean when we're looking at these waves – just being on the shore is quite fascinating to me. The sea life to me is just glimpses of the life that's in the ocean, so my mind extrapolates from what I've seen. And then there's the distance to the shore and the fact that the ocean is not exactly the most hospitable place for a human to be, and your ship is the only thing that's making it liveable – just like in deep space.

 

[Asbo Zaprudder]

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.

Uhuh and which abyss would you be looking at out the porthole of a ship? Just asking, like, since all I ever saw was sealife and waves. And weather. In UK waters at least you never see much below 2 meters no matter what the depth, so you could be over a trench or in 3 meters.

See definition 2 - I believe the poster was using poetic imagery rather than being merely literal.

 

[Deckerd]

The big difference between being on a boat and being in a tin can is, I suppose, that if you fall off the boat you have a decent chance of not dying.

 

[Asbo Zaprudder]

Columbus's or Magellan's expeditions probably wouldn't get funded or crewed now because of the inherent risk.

 

[Crazy Eddie]

A mining business would mean transporting heavy ore all the way to earth.

The first two letters if ISRU stand for "in situ." If the business spends some extra fixed capital developing the ability to process those ores into raw metals right where they're mined, then you don't need to send ores, you can send rolled sheetmetal of various alloys (including some you can't make on Earth) back home.

Any propulsion system that uses chemical energy would be inadequate for this task

Speaking as someone who has actually run the numbers on this, you are incorrect. An eight ton spacecraft with twenty tons of propellant could carry six tons of ore OR refined metals to an Earth-impact trajectory. A more ideal situation would be to haul eight or nine tons into lunar orbit and stick it on a VASIMR-powered space tug for the trip home.

Indeed, chemical reactions simply don't generate enough energy. The craft so powered are too expensive to build and maintain, use FAR too much fuel, are too slow, too heavy, have too many failure modes.

So do helicopters, and yet we still use them.

A true interplanetary society must use nuclear power (fission or fusion); nothing less suffices for easy (more or less) interplanetary transport.

That or an assload of patience.

 

[Crazy Eddie]

Also, read about the mission architecture I sketched above - you go to an asteroid to stay, for years (at least until the next launch window, when you'll be replaced by another crew), in order to mine it. You bring industrial equipment, etc, and your first task is to become self-sufficient (as in you won't need expensive shipments from earth merely to survive) aka build the O'Neill colony/space station/whatever with the initially mined ore. Only afterwards, will you start to send the ore to earth. The investment will amortize itself in decades, if necessary (not in a mere few years).

You're not going to become self-sufficient using the resources on an asteroid. To begin with: little or no accessible water (from which you get oxygen, fuel, and... well, WATER) and Earth resupply is complicated and irregular.

You're probably better off starting with a lunar outpost and using the resources there. It's not as rich as an asteroid, but then again neither is Earth and we've been mining THAT for centuries.

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.

That depends ENTIRELY on your setup costs. A fifty billion dollar space mission that nets fifty billion and twenty thousand dollars worth of precious metals isn't exactly turning you a fortune. You can't wish away the up-front costs as if they will never matter.

Perhaps the politicians are the culprit, and not the engineers.
But Nasa is composed of both.

No, NASA is not. The Kay Bailey Hutchinson is NOT a member of NASA and neither is Ben Nelson, despite the fact that the two of them designed the Space Launch System pretty much single handedly.

They say an elephant is a mouse designed by committee; X-37B is what the space shuttle would have looked like if NASA wasn't being used as a bork-barrel cookie jar for the U.S. Senate.

So - what are the reasons for discarding Apollo, sojourner?

Similar to the reasons for discarding my grandfather's model-T ford: it no longer exists, and it didn't work all that great when it did.

The fact that Saturn hasn't been built in 30+ years should be of little consequence as long as the complete plans are available.

NASA will sure be relieved to hear that! Why don't you go over there and break the news? I'm SURE they never even thought of that.

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

Primarily, this is because the designs for a working SLS are of identical value to the designs for a working Saturn-V. Just because you have pictures of its parts doesn't mean you can BUILD it.

What exactly makes the tooling for Saturn so expensive, sojourner?

You don't actually know what tooling IS, do you?

 

[sojourner]

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.

Nope, wrong again. no goal posts moved here, we were talking about the difficulty of construction in orbit and specifically welding. as seen in this post:
http://www.trekbbs.com/showpost.php?p=5276414&postcount=68

You started talking about 30 years of NASA inefficiency here:
http://www.trekbbs.com/showpost.php?p=5276868&postcount=80
to which I try to steer you back on topic here:
http://www.trekbbs.com/showpost.php?p=5277101&postcount=87

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

The fact that Saturn hasn't been built in 30+ years should be of little consequence as long as the complete plans are available.

of little consequence???? You do know that replicators haven't been invented yet?

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 problems with SLS? please enlighten us. SLS is being designed to use as much of the shuttle infrastructure and construction tooling as is feasible. It uses the same engines, nearly the same boosters (5 segment as opposed to 4 on the STS) The external tank diameter is the same allowing the core to be built using the existing manufacturing tooling from the STS external tank. Hell, we already have about 15 engines ready to go - surplus from the shuttle fleet.

What exactly makes the tooling for Saturn so expensive, sojourner?

It doesn't exist.

 

[MANT!]

The tooling for the Saturn series rockets was destroyed long ago, along with many of it's engineering records..

When the Shuttle was selected as the way to go, almost anything that was related to the Saturn project was simply tossed..after all, Congress didn't authorize any more Saturn V construction after the first batch, and the assorted companies involved really didn't want to spend the money to store the tools and information....

And if you think developing it from scratch is expensive, try reverse-engineering..

 

[sojourner]

^It's an urban myth that the designs for building Saturn were lost. Complete blueprints still exist. The manufacturing methods for those plans, well, that's another story.

 

[Asbo Zaprudder]

I imagine that some of the details of the precise techniques of manufacture might have been lost forever - for example, the processes that were used to reduce the mass of the S-II stage while preserving its structural integrity.

 

[MANT!]

^It's an urban myth that the designs for building Saturn were lost. Complete blueprints still exist. The manufacturing methods for those plans, well, that's another story.

Strange, then the Jarvis rocket (proposed after the Challenger disaster) should have been a slam dunk..except for the afore mentioned records jettison by Rocketdyne..

I distinctly remember one of the reasons for the No-go on Jarvis was the lack of designs for the F-1A engine..And that the cost of reverse engineering was considered prohibitive..

I could be wrong, but as it was in The 1987 "Air Force" magazine..

Who knows?

 

[RobertVA]

Over nearly half a century there's probably been some turnover in the suppliers of parts and material used to build the Saturn rockets. Even if a supplier is still in business some of those parts and/or materials may have been discontinued decades ago. Some fabrication processes are dependent on the skill and/or experience of NASA or supplier personnel that retired or died decades ago.

The design of the equipment used to build the Saturn components might not be as well documented as the design for the components themselves. That might include things like fixtures that support the tank while they are fastened together or a device that holds a part while it's being machined.

For every part or material that's no longer available a substitute has to be identified and evaluated. There would probably be enough changes to require new launches and other testing to obtain enough confidence to put expensive payloads or crew on the rockets.

 

[HopDavid]

Over nearly half a century there's probably been some turnover in the suppliers of parts and material used to build the Saturn rockets. Even if a supplier is still in business some of those parts and/or materials may have been discontinued decades ago. Some fabrication processes are dependent on the skill and/or experience of NASA or supplier personnel that retired or died decades ago.

The design of the equipment used to build the Saturn components might not be as well documented as the design for the components themselves. That might include things like fixtures that support the tank while they are fastened together or a device that holds a part while it's being machined.

For every part or material that's no longer available a substitute has to be identified and evaluated. There would probably be enough changes to require new launches and other testing to obtain enough confidence to put expensive payloads or crew on the rockets.

The Saturn Vs were very large expendable rockets. About 10 billion a pop.

With very low flight rate, it's hard to amortize the design and development expense for monster HLVs. It looked like the Ares HLVs were going to be in the same ball park as the Saturns. I am not optimistic about SLS, either.

Building infrastructure on the moon, Mars, or an NEO would take many missions. Long before a space base came close to achieving a return on investment, a future Lyndon Johnson or Dick Nixon would say "This manned base is nice, but we can't afford it in these tough economic times. I will cancel it deader than Apollo."

Disposable mega rockets aren't sustainable. That's a dead end architecture.

 

[sojourner]

Strange, then the Jarvis rocket (proposed after the Challenger disaster) should have been a slam dunk..except for the afore mentioned records jettison by Rocketdyne..

I distinctly remember one of the reasons for the No-go on Jarvis was the lack of designs for the F-1A engine..And that the cost of reverse engineering was considered prohibitive..

I could be wrong, but as it was in The 1987 "Air Force" magazine..

Who knows?

I think that Airforce magazine was wrong. Here's a great article on the whole Saturn/F-1 issue:
http://www.thespacereview.com/article/588/1