NASA and the Vision thing

a écrit dans le message de news:
...

Hydrogen going through Uranium Oxide close to the melting point. The
Nerva engine was reckoned to be 3 times better than a chemical
propellant.

Actually twice as good, IIRC. Nerva had an Isp of 960s, vs 460 to 480 for
current crogenic chemical engines. ( of course, ionic propulsion is much
better from that PoV )

On Fri, 25 Nov 2005 23:17:38 -0500, "Scott Hedrick"
wrote:


wrote in message
oups.com...
"Who is Elle Marche?"

It means it works in contrast to the Shuttle which has problems
working.

I understand that. However, almost nobody else does.


What you've done, like so many other kooks, is heard a few rumors
involving
"someday, maybe" underfunded technology and believed the hype. Your
argument
is unpersuasive.

Conventional rockets, the Shuttle, Ariane and the Saturn C5 have
cryogenic upper stages. This gives an exhaust velocity of some 4km/sec.

And right there you've just put your involuntary venture capitalists to
sleep.

Telling the American taxpayer to stop using homegrown technology and to buy
foreign rockets, particularly French made products, will not only get you
laughed at, but might even get you Sibreled.

There goes a tangent for my suggestion for common space access. :-

If you argue tech, you will not get funded. Logic is not relevant to the
process. If it was, we'd be making active progress to Mars using some of
Zubrin's ideas.

--

Christopher

Pat Flannery wrote:

White House doesn't seem keen on funding its own new program.
I'm glad you noticed! Nasa is the most successful government
department ever! Its job is to keep civilians out of space and it has
done so very well. Look at the results and you will see the reality of
that statement.
Boeing and the Airfarce Space Command belong in space but citizens do
NOT, according to the powers that run the US. And Bush follows
directions. So, although he says the guv's trying to get into space and
wants your kids to go to space camp to learn to be an astronaut, the
chances of that happening are a billion to one. Just grow up.
Space is the high ground. Space access is strategic military power.
The Structure does not want us there, space cadet.

of course, ionic propulsion is much better from that PoV )

Indeed it is. I should have mentioned that. One still needs
breakthroughs I claim. For manned spasceflight you have 2
possibilities.

1) The development of a thin photovoltaic material which could power up
the engine.

2) Nerva type technology operating on a closed cycle.

"1" would have considerable spin off as you could put such a sheet on
the roof of your house, or spread it out on the floor of a desert.

However ESA has reached the Moon using an ion drive. NASA is spending
the vast majority of its money on old dead end technology.

There is one point which a lot of contributors has touched on, the fact
that NASA will use inferior technology just because its American. I an
in fact a European, but if I was an American I would not be prepared to
spend a cent on macho technology.

Anyway is it macho to advertise to the world that despite your throwing
of money at the Shuttle it is STILL inferior to competing systems?

wrote:

Right, and just continue to launch them with expensive expendable.

This is just NASA propaganda. Expendibles cost LESS than the Shuttle
(per kg)

Earth to Ian ...

NASA doesn't launch expendables.

NASA launches the shuttle.

All are expensive.

http://www.lifeform.org

http://cosmic.lifeform.org

On Sun, 27 Nov 2005 05:51:37 -0600, wrote
(in article . com):

You're seriously confusing exhaust velocity, delta-V and specific
impulse. Go take an astrodynamics class or at least read a book and do the
math.

Hydrogen going through Uranium Oxide close to the melting point. The
Nerva engine was reckoned to be 3 times better than a chemical
propellant. With fusion you directly mix the stream of gases. 50km/s
since you are not dependent on solid materials.


You're still obviously confusing ISP, delta-V and exhaust velocity.
Until you can demonstrate that you understand the differences, enjoy
your stay in my killfile.


--
"Fame may be fleeting but obscurity is forever." ~Anonymous
"I believe as little as possible and know as much as I can."
~Todd Stuart Phillips
www.angryherb.net

On Thu, 24 Nov 2005 08:34:07 -0600, Pat Flannery
wrote:

..... the
White House doesn't seem keen on funding its own new program.


Dwayne Day did an excellent piece in SPACEFLIGHT a month or two ago
about how Bush has supported his vision. The paragrpah in the MSNBC
article about Tom DeLay's "arm twisting" a couple of years ago
neglects the fact that when Bush didn't mention his vision in speeches
after the announcement, Congress thought it would be ok to cut NASA's
budget. Bush then said that he would veto any bill that cut NASA;
THAT's when DeLay started twisting arms. Since then, no cuts.

Dwayne also outinlined how Bush will talk about his vision and express
confidence in NASA *when asked,* but otherwise won't say anything.

Based on that, it's hard to see how the Bush White House could have
reversed gears and decided not to support its own program. Possible,
but I doubt it. More likely they still do support it, but just don't
talk about it publicly, as before. Of course, one could always ignore
that possibility and fall back and believing the worst of President
Bush. But that might not be lined up with reality.




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"Rand Simberg" a écrit dans le message de
news: ...


What is that's inferior about American rocket technology, relative to
European?

Relative to european as in EU, I don't think there is any. There may be some
points on which the current rockets from one or the other are better, but I
think the technology is equivalent in that anything one does, the other
could, if it wanted to make the investment.

Russian rocket technoly, not still has some edge ( which they're busy
loosing )

In article ,
Rand Simberg wrote:
However ESA has reached the Moon using an ion drive.

So has America (in fact, a private company, Hughes, did it).

No, the US hasn't flown any ion drives to the Moon. Hughes did swing a
stranded comsat around the Moon a couple of times, but I don't recall ion
propulsion playing any particular part in that.

There's no question that the US is capable of doing it, mind you.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On 27 Nov 2005 08:23:32 -0800, in a place far, far away,
made the phosphor on my monitor glow in such a
way as to indicate that:

However ESA has reached the Moon using an ion drive.

So has America (in fact, a private company, Hughes, did it).

NASA is spending
the vast majority of its money on old dead end technology.

There is one point which a lot of contributors has touched on, the fact
that NASA will use inferior technology just because its American.

What is that's inferior about American rocket technology, relative to
European?

Anyway is it macho to advertise to the world that despite your throwing
of money at the Shuttle it is STILL inferior to competing systems?

Almost everyone recognizes that, not that it seems to have anything to
do with the rest of your post.