President "Bush Delivers Remarks On U.S. Space Program

[London Geezer]

What the protestors failed to realize was the actual risk involved: the increase in radioactivity that would result from the destruction of Cassini would have been equivalent to a 15,000th of a normal lifetime absorption of radioactivity. There is most likely more radioactivity in a tanning booth or dental X-ray.

Oh... Didn't know THAT...

(If all that stuff is true, of course. In the end the americans are also the ones not agreeing with the Kyoto agreement because "there is no proof that global warming is caused by us"... Being very skeptical lately on everything coming out of the US)

 

[StefanS]

... Being very skeptical lately on everything coming out of the US)

Of course you are, you're from the Shire

Back on topic:

Nobody plans to launch nuclear propulsion on planet Earth.

 

[Bouncing Zabaglione Bros.]

All the commentators here pointed out that George Bush senior had announced the same thing during his presidency, to the same big fanfare. That lasted only until the cost estimates came back.

 

[zidane1strife]

I'm not sure it's possible, but I think I heard the russians are going to try and reach mars by 2018(manned)...

 

[StefanS]

I'm not sure it's possible, but I think I heard the russians are going to try and reach mars by 2018(manned)...

Russia got lots of the best engineers of the world, but I don't know if they have the money to do it.
But at least they have started to build a replica of an S/C capable of going to Mars. In this facility 4 cosmonauts have to survive for 4 years on their own... We'll see...

 

[Neeyik]

Any argument about space exploration by humans being a waste of money is rather moot when one considers that the British population alone spends around £3 billion on chocolate each year. 8)

 

[Fred]

'In the end the americans are also the ones not agreeing with the Kyoto agreement because "there is no proof that global warming is caused by us"... '

See I'd turn it around, and say 'I'm very skeptical of anything that has politics attached to it'. The environment is a place where bad science thrives, many environmentalists a breed without the use of Popper. Kyoto was a premature, reactionary movement that was pretty much not thought out well. It will need to be done at some point, but the technology is probably not quite there yet (hydrogen).

Unfortunately, this also applies to Nasa. I'm still highly skeptical of the advances that have been attributed to the space program. In a time when scientists have to fight amongst each other for funding, its somewhat natural to question the veracity of the claims. From a scientists perspective, the one indisputable, greatest achievement was the Hubble telescope (probably the greatest experiment in human history in terms of knowledge gleaned)

Look, everyone loves the idea of the ISS, Mars landings, and a Moon base. And its somewhat obvious that the latter will happen during the course of human endeavours.

Whether it should be now, as opposed to say, 20 years from now is subject to debate. The only troubling thing about sitting around though, is the appaling lack of advances in rocket technology...

Here;s to hoping a genius businessman comes up with a plan to make money, so that all of this can be privatized (where it belongs).

 

[RussSchultz]

I'm still highly skeptical of the advances that have been attributed to the space program. In a time when scientists have to fight amongst each other for funding, its somewhat natural to question the veracity of the claims.

There are certainly obvious benefits from NASA research in the past. We can only speculate that similar benefits are happening now and will reveal themselves to be important in the future.

If you're skeptical, maybe you out to look and educate yourself, rather than remaining ignorant.

(Sorry if it sounds harsh, but there are obvious past inventions/advances directly attributable to the space program. Being "skeptical" of them means you must not know about them)

 

[zidane1strife]

Here;s to hoping a genius businessman comes up with a plan to make money, so that all of this can be privatized (where it belongs).

Well, after going through some links in the site from that other thread(blackholes, etc.), I found some interesting info...

Supposedly, using diamond as a material future spacecraft could be just as strong as modern ones but weight 1/20th what they do now. If that is indeed true, then it is only a matter of time...

 

[DemoCoder]

Carbon nanotubes, if they can ever be manufactured in macroscopic quanities, are a quantum leap above our strongest materials today. A single wall nanotech has a Young's Modulus of 1054 gigapascals, and a tensile strength of 150 gigapascals. Compare with Steel's 208 modulus and 0.4 GPa tensile strength, or Wood's 16 and 0.008 GPa.

Now only this, but CNT's have a density of 2.6 grams per cubic centimeter while steel is 7.8. They easily exceed the requirements needed to build a space elevator.

Think of it this way: A 2-inch diameter CNT cable could suspend 68 million pounds, OR, the equivalent of 15 fully fueled and loaded space shuttle orbiters. A steel cable capable of achieving the same thing would have to be atleast 1 meter thick, but it would weight 150 times as much!

 

[Snyder]

Carbon nanotubes, if they can ever be manufactured in macroscopic quanities, are a quantum leap above our strongest materials today. A single wall nanotech has a Young's Modulus of 1054 gigapascals, and a tensile strength of 150 gigapascals. Compare with Steel's 208 modulus and 0.4 GPa tensile strength, or Wood's 16 and 0.008 GPa.

Now only this, but CNT's have a density of 2.6 grams per cubic centimeter while steel is 7.8. They easily exceed the requirements needed to build a space elevator.

Think of it this way: A 2-inch diameter CNT cable could suspend 68 million pounds, OR, the equivalent of 15 fully fueled and loaded space shuttle orbiters. A steel cable capable of achieving the same thing would have to be atleast 1 meter thick, but it would weight 150 times as much!

A space elevator would be nice and I really love the concept, but I still have my doubts that it is possible - even with nanotubes.
A cable to a geostationary orbit would be (IIRC) 35780 km long, which would result in a weight (calculated with above density) of about 182.690 metric tons. I don't think a nanotube cable of this length could support it's own weight - or am I overlooking something?

Oh. Damn. I did overlook decreasing gravity. Oh my, integral calculus has been a loong time...let's see...gravity force is inversely proportional to the square of distance to earth's center...dammit - I'm too tired to do this right now.

Another thing I'm interested in: How problematic are winds for the construction? Is there some solution for this problem or is there actually a problem?

 

[RussSchultz]

Actually, you don't need to worry about compressive strength of the space elevator. You can design it such that that net pull is outward(upward), and not inward.

Think of a ball on a string & centripedal force.

 

[Razor04]

Carbon nanotubes, if they can ever be manufactured in macroscopic quanities, are a quantum leap above our strongest materials today. A single wall nanotech has a Young's Modulus of 1054 gigapascals, and a tensile strength of 150 gigapascals. Compare with Steel's 208 modulus and 0.4 GPa tensile strength, or Wood's 16 and 0.008 GPa.

Finally some language that makes sense to me! I am much much better at understanding Mechanical Engineering stuff (which I have gone to school for) than half of the advanced video stuff around here. But most of all it is posts like this that keep me coming back here. Well educated people having civil discussions (for the most part) on advanced topics.

 

[Nexiss]

Actually it's 540 Billions, to which Bush contributed with a tiny fraction (540 Million), and it's common knowledge to anyone who reads papers. Not sure what kind of stories you get there where you are, but here the papers said it all this morning...

I have seen all kinds of quotes in the papers as to cost. Really, it depends on who you ask. I have seen some plans for (just) a Mars mission that would cost significantly less.

Anyway, I certainly welcome the advancement of our space technologies and efforts.

 

[Fred]

I'm not going to argue that there is plenty of stuff that has come out of NASA that is undeniable and very worthy, only a fool would think the opposite.

There are however many outlandish claims though. Like the weird statistic that for every 1 cent of money spent in NASA, that it outputs 100fold to the economy. That the space program popped out the technology for GPS, etc. Surely you can see that claiming credit for the latter is a little bit over encompassing.

But lets stick to the topic, what science is likely to come from going to the moon and setting up a base there, that couldn't be done on labs here on the earth? I don't think its evident that we're going to get much out of the actual event. Rather its the technology to actually go there, that might output something interesting. The argument then is, why spend all the money on the last step, when most of the interesting things can be done here on earth. I suppose there is some biological interesting research. Like how Humans might adapt to low gravity conditions (over and above what we already got from MIR), and what not.

Look im not going to sit here and argue against progress in my own field But the reality of the situation is, often these funds are in competition with each other. For instance, the zeal to make environmentally friendly alternative sources of energy has cut into the NSF funding for all sorts of other fields of inquiry, like the demised SSC.

 

[Wunderchu]

on the topic of beneficial developments resulting directly and/or indirectly from the space program;

http://www.ethicalatheist.com/docs/benefits_of_space_program.html




(that link was posted by Andrew LB in this thread on Rage3D:
http://www.rage3d.com/board/showthread.php?s=75121b69a854930a3f3e4db312e82872&threadid=33736116 )

 

[DemoCoder]

Yes, the funds are in competition with one another, but the solution is to lobby for more funds. I think the cancellation of the SSC was a TRAGEDY given the money already spent on it. And look how many hurdles LIGO and Gravity Probe B had to hop through.


As I said over and over again, the point of going to space isn't just the science, it's the engineering. We have to create artificial demand for new launch systems. That won't happen if everyone is designing el-cheapo robots that fit on Delta launchers.

The cold war created the artificial demand that propelled today's launch systems. Had it not been for ICBMs and the Space Race, I highly doubt there would be commercial satellite TV or communications today, because the costs and risks to develop the technology are too much for short term investor's or corporations to deal with.

But the cold war is over, and there is nothing that pushes the demand for cheap reusable and heavy lift launchers today. As a result, technology has stagnated. Likewise, in the aerospace realm, except for military apps, technology has stagnated. With airlines losing money, and the fact that Boeing and Airbus's current line up is "good enough", there is no real large push to change.

The reality is, NASA is the only consumer of these technologies. Without the government saying "we need X", there is no impetus to develop new propulsion systems or radical new designs.

We all want science to be pushed forward. But we also want engineering to go forward too. The fact is, the knowledge of cosmology benefits us, but is is the engineering and materials science from the space program that benefits us more in the short term.

It is, sadly, up to the government to create artificial demand in the beginning for these megaprojects in order to get their development started faster. Maybe it won't pan out, maybe it will (e.g. DARPA and internet), but the money spent isn't ridiculously wasted like some of the other things we spend it on (e.g. Iraq War)

What new "spinoffs" are gonna come out of rebuilding Iraq?

 

[akira888]

A space elevator would be nice and I really love the concept, but I still have my doubts that it is possible - even with nanotubes.
A cable to a geostationary orbit would be (IIRC) 35780 km long, which would result in a weight (calculated with above density) of about 182.690 metric tons. I don't think a nanotube cable of this length could support it's own weight - or am I overlooking something?

Actually, in SI "grams" is the core unit of mass, not weight. The unit of mass in English measurements is "slug", which at sea level weighs a hair above 32 pounds, and the core unit of force/weight in SI is "newton." That being said I will treat "gram" as a weight equal to the force exhibited by one gram of mass at Earth's sea level, since I'm more comfortable with those units than newtons.

The size of a cross section of cable is 2 inches in diameter, or 2*2.54 = 5.08cm, which gives us a 2.54 cm radius (1 inch). The cross section area is 2.54^2 * pi = 20.268 cm^2. There are 100000 cm in a km which gives us a volume of 2026800 cm^3 of nanorope in a kilometer's length, or a weight of 2.6 g/cm^3 * 2026800cm^3 = (2.6*2026800)g = 5270 kg per km of cable length at sea level. Assuming no distance attenuation for gravational force we get a "weight" of 5270 kg/km * 35790 km to the Clarke belt = 188613 Metric tons. (Some of our inputs were slightly different - but we're within an order of magnitude so it's all good )

With proper grav. force falloff with increasing distance we integrate our equation from sea level (6380 km) to the Clarke Belt (42170 km). So we have - absent LaTeX - this monstrosity where the term in parenthesis is equal to 1 at sea level and is inverse-square proportional with respect to distance, and 5270 is our kg/km density -

        42170        ( 6380^2 )
Integral      5270 * (--------)  dx
        6380         (  x^2   )

Moving constants outside and solving the rather simple definite integral gives me ~28500 metric tons. Note that I have not taken Calculus I since HS junior year 96-97 so I might easily be wrong.

 

[K.I.L.E.R]

You mean like moon cookies?

I'm still highly skeptical of the advances that have been attributed to the space program. In a time when scientists have to fight amongst each other for funding, its somewhat natural to question the veracity of the claims.

There are certainly obvious benefits from NASA research in the past. We can only speculate that similar benefits are happening now and will reveal themselves to be important in the future.

If you're skeptical, maybe you out to look and educate yourself, rather than remaining ignorant.

(Sorry if it sounds harsh, but there are obvious past inventions/advances directly attributable to the space program. Being "skeptical" of them means you must not know about them)

 

[Sxotty]

2) You can't launch electrical space propulsion systems from the surface of the moon, but you can launch them from ISS
3)So we're stuck on the moon now and we have our spacecraft assembled already. Then we're launching it again against gravity (another waste of resources and money)
...

BTW you are missing something, something called the atmosphere and the moon doesn't have much of one, thus you could use a rail gun type thing to launch capsules off it, that is electricity used to power the launch, and yes it really would work quite easily, the reason it doesn't work well here is the atmosphere creates to much drag and as you know the escape velocity is much lower on the moon.