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Comment Not theory (Score 1) 103

Unless you have actually tried to build a rotating space station, your answer is also theoretical.

They have tried to extend tethers in space, and run into multiple problems caused by them being not-rigid. Gemini 11 (which was tethered to it's Agena to test just these things) encountered problems with spin-up due to this and other dynamics issues. The problems I cite spring directly from experience, mathematics, and engineering.

So no, my answer isn't theoretical.

Comment Re:Artificial Gravity (Score 4, Insightful) 103

From what I've read, it can be done cheaply with a long tether and a counter weight at the other end.

It can be done cheaply in theory... In practice, there's all sort of complications with tether deployment, spin up, and stability. Plus you can't dock with a station spinning like that, so now you encounter the practical problems with spinning down. (All these problems are caused by the fact that tethers aren't rigid.) Any time you need to maneuver the station (for re boost or to avoid debris), you also encounter the spin-up/spin-down problems. Then there are the problems the spin causes in keeping your solar panels aligned with the sun, and your radiators aligned away from the sun. Any directional antennas also suffer from the same problems. Etc... etc...

Easy in theory, difficult in practice.

Comment Re:Reckless endangerment (Score 1) 185

It varies a lot by state (and even more outside the US). The intent to kill isn't a hard requirement for attempted murder - sometimes the line is drawn at an intentional action that could reasonably cause death. Seems like the sort of charge an ambitious prosecutor might try on.

Also worth noting: if maliciously calling in a fake 911 call is a felony, then in most states it would be murder if someone actually died as a result.

Comment Re:How much to re-create Apollo? (Score 1) 277

If you can get - for the same launch cost - not 70 tons, but 1400 tons to orbit, even if they are in 54 ton, not 70 ton lumps - it starts being really questionable what the benefit of the 'shuttle derived' heritage is buying you.

It stops being questionable when you stop comparing prices - and start comparing what you get for those prices. Splitting the payload increases the amount of parasitic mass, I.E. non payload mass such as the support systems the payload requires until joined up in the final assembly. Splitting the payload also considerably increases the total risk of the mission - both by increasing the number of launches required and by adding rendezvous, docking, and assembly steps not required by a unitary payload.
 
Seriously, while I can't and won't argue the SLS is a good idea - there's a lot more to the equation than simply price. My minivan is much cheaper than a full sized pickup truck, but nobody sober and in full possession of his senses would ever confuse one for the other. No sane person would ever send one to do the other's job.

Comment Re:How much to re-create Apollo? (Score 1) 277

How expensive would it be to re-create the Apollo program?

Outrageously expensive - because pretty much every piece would have to be re- or reverse- engineered, production facilities established and qualified, all of the production and part QA processes and procedures re-established and re-validated, etc... etc...
 

In other words, would we save $BIGBUCKS by building on what we have instead of starting nearly from scratch?

The problem is... there's nothing to build on. Apollo is over forty years in the past, and there's nothing left of it. Zip, zilch, NADA. Pretty much very manufacturing process has changed (they welded together parts we'd machine in one piece out of a single block nowadays for example). A good chunk of it's electronics were analog - and used very low part count IC's (for both digital and analog) that were manufactured using processes that haven't been used in decades. Etc... etc...

Beside which - what makes you think an Apollo-Saturn launch was cheap? In current year dollars, they cost over a billion a pop out of pocket. (I.E. not considering sunk costs or amortization.)

Comment Re: Great idea... But there is a problem... (Score 1) 277

Delta-V costs are not the only criteria.

The number one limiting factor of any space vehicle is cost per kg at launch. NASA could build a Mars vehicle any size they wanted except they have to figure a way to get it in orbit without spending the entire budget to launch it.

Irrelevant when the number one defining factor of STS is how much pork can be siphoned off to spend into each supporting senator's district and not whether or not it helps the an extremely improbable Mars mission or even just the improbable "planned" moon flyby.

You're the one proposing that it is "easier [to] refuel at the moon" [sic] so the onus is on you to detail how much developing a moon base

I am not proposing. I am relaying what has been proposed.

We're not in junior high here, you can stop trying to play semantic games. You bring the subject to the conversation, you defend it. Knowing that there is hydrogen on the Moon does not mean that it is under the form of water ices nor how accessible it is nor how difficult and expensive harvesting it may be.

sufficient to perform extraction of fuel/oxidizer and the means to transfer them to earth launched vehicles are versus doing so from earth.

No oxidizer is required for electrolysis.

You cannot know that lunar hydrogen is in the form of water ice, have not proven it's accessibility, have not proven that you have worked out the process to develop it as a usable ressource nor proven that you can do so for less than it will cost at that point in time to deliver from earth. Pray do so now.

Don't forget that spending billions to develop a rarely used infrastructure is precisely the point that most critics of NASA have at present...

1) I didn't say it would be easy. I said it would be "easier".

Proof? Nah you don't have proof (indeed you _cannot_ at present) and if this post is any indication you'll try playing semantic games again to attempt to avoid answering.

2) How much fuel is left in a space vehicle after Earth orbit is reached? Very little. There's a reason most space probes use gravity assists to speed them towards their destination. And being unmanned they don't have constraints on time and resources that manned missions will have.

Oooh, ooh I know this one! it's because Nasa, being hobbled by the U.S legislature never invested significantly in lowering the cost of launching mass to orbit, preferring to spend the money on futile studies as the only meaningful yardstick became $$$/district.

3) NASA has been directed to do something; you may not like what they propose but that doesn't mean they can refuse to do it. Get to Mars is directive. For NASA that means getting to the Moon again.

You seem to have been living in a cave with no contact with the exterior for the last few months. Allow me to enlighten you: Nasa's congressional masters and the president have changed. No-one knows exactly what the implications are yet but Trump's declarations that cost cutting is more important than rockets to nowhere means that the directives are to change soon and Mars is not likely to be a directive for much longer.

"Current" NASA plans have a tendency to change with administrations.

Engineering and numbers don't change with administrators. Math is math. What is the cost of launching directly from Earth vs launching from the moon.

Spoken like someone who lives off of studies that will never come to fruition.

Comment Re: Great idea... But there is a problem... (Score 1) 277

I think you're confusing "a moon base" with "a full industrial infrastructure capable of producing complex objects". Even the concept that it would be cheaper to launch unrefined raw regolith from the moon cheaper than we can launch equivalent mass payloads from Earth anytime even remotely soon is absurd.

Nowhere did I say that NASA needs to rebuild and entire installation; however, in terms of fuel cost it is much easier to launch from the Earth to the moon then refuel at the moon to launch at Mars than to launch from Earth directly to Mars. Do the math.

Delta-V costs are not the only criteria. You're the one proposing that it is "easier [to] refuel at the moon" [sic] so the onus is on you to detail how much developing a moon base sufficient to perform extraction of fuel/oxidizer and the means to transfer them to earth launched vehicles are versus doing so from earth. Don't forget that spending billions to develop a rarely used infrastructure is precisely the point that most critics of NASA have at present...

Earth is where industry is. The fact that we're a deep gravity well increases costs, but that difference is nothing compared to the difference in industrial capacities on and off Earth. Every production process has feedstock and consumables dependency chains. Those have dependency chains, and those have further chains, to a massive network of ever-increasing complexity. One of the worst dependencies is humans, which in turn spawn massive dependency chains.

Current NASA plans have the moon as a refueling point. That requires a moon base.

"Current" NASA plans have a tendency to change with administrations.

Comment Re:Death To All Jews (Score 1) 910

But why should there be a risk?

It's newsworthy is PDP turned out to actually be a white supremist or somesuch, given his following. But that's clearly not the case here. This was simply "PDP did something tasteless, like so many of his videos", not even newsworthy.

But it's not about truth or what newsworthy, is it? It's about forwarding the narrative, and punishing the heretics. And only that.

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