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Space Exploration Timetable?

Posted by: Texan - Sun Jun 27, 2004 1:16 am
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Space Exploration Timetable? 
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Post    Posted on: Sun Aug 15, 2004 3:18 pm
Pete wrote:
The European powers sailed around claiming whatever they could in the name of their governments. Possession wasn't 9/10ths of the law, it was 10/10ths and whoever had the most guns claimed sovereignty. Therefore if the land was valuable, you'd have a battle over it and the for the rest, it was a scramble to get there first.


Damned straight. The first group to establish a permanent base on the Moon has the ability to defend the entire bloody planet against all comers (Heinlein's The Moon is a Harsh Mistress underlines this rather well), if they set themselves up right. Fortunately, as you said, the Moon isn't terribly valuable, except for raw materials and for use as a spaceport.

Unless somebody does what the railroad companies did to the American West back in the 19th century, and develop such a marketing campaign as to make every last little Godforsaken rockstrewn plot on the Moon more valuable than gold itself.

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Just a note to the mods, but doesn't this fit better in the Café?

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Post    Posted on: Sun Aug 15, 2004 5:24 pm
Defending the moon will be many degrees more risky, damgerous and difficult than defending a country on earth:

1. No usual airforce can be used because there is no atmosphere. So only rockets or spacecrafts like SS1 or the Shuttle are usable as a substitute for airplanes.

2. No navy can be used because there are no oceans and rivers.

3. Because of the lack of an atmosphere there is no pressure on the moon and that means that in war there will be no difference between a deadly shot by a gun and an only wounding shot by a gun. You will be ded at once if you bcaome wounded.

Concerning 1 think of the costs of NASA spacecrafts, the investment costs of the Shuttle, the propellant cost of the Shuttle and the launch costs of the Shuttle - and you have to add the transportation costs to the moon.

Today no country will be able to finance any war on the moon. If one day in the far future there would be living millions of people on the moon this people might be able to finance an earthlike war there - but they won't do that because the losses will be much higher than on earth: Take the wounded of World War II and add them to the fallen.

What might be possible is a war on earth caused by rivalry for the moon, moon stations, moon sites etc. But even such a war doesn't be in the interest of the rivals - this war might destroy the launch sites and the landing sites.

The discussion is concerning the Space Exploration Timetable and I would have expected defense of the moon and war concerning the moon to be discussed where ownership of the moon etc, or property rights concerning the moon are discussed. But as a perspective - at the moon freedom will be much more safe than on earth if there is freedom first but dictatorship will be much more safe too if there is dictatorship first on the moon. This is due to the extremely high danger on the moon. ...



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Tue Aug 17, 2004 2:05 pm
Ekkehard Augustin wrote:
Defending the moon will be many degrees more risky, damgerous and difficult than defending a country on earth...


Nope. Lunar defense is insanely easy. Here's why. Go into your kitchen and find yourself a really, really big bowl. Like the kind of bowl used to make salads in (a vat of some sort is even better). Say the bowl is 6cm in diameter and 3cm deep. Then find a smaller bowl: 1cm in diameter and .5cm deep. Take the small bowl and tape it on the outside of the big bowl, so that the tops are even.

Congratulations, you've just made a simple model of the gravitational physics of the Earth/Moon subsystem. The bottom of the big bowl is a point on the surface of the Earth, and the bottom of the little bowl is a point on the surface of the Moon.

Note that an object going from the Earth to the Moon has to fight gravity almost all the way. In contrast, an object going from the Moon to the Earth is "sliding downhill" most of the way. In essence, the Moon is at the top of a hill, and the Earth is in the valley below it. The Moon has the high ground, and is therefore much more easily defensible: anything coming from Earth has to push against gravity, and (to save on fuel) will have to go almost directly at the Moon. Also, a Moon trip takes several days in space. All this makes them a slow, steady target -- the kind of thing that gets artillery men drooling.

Beyond that, most Lunar colonies (especially early ones) will be underground to protect the colonists from radiation. So they're already well fortified (you need a lot of rock on top of you to keep high-energy radiation out), making them even more easy to defend.

In short, the Moon's a big fortress at the top of a hill. They don't have to worry about hand-to-hand combat, because they can pick off their attackers at their leisure before said attackers even make it up the hill.

And to answer your points:

1. Air force isn't necessary -- put a cheap sattelite in orbit, or just lob artillery to your target (guns on the Moon have six times the range).

2. Navy's irrelevant, because you can either use your space-based forces, artillery, or use the lunar versions of tanks and troop carriers -- land-based forces are more effective than ships anyway.

3. Granted, but there's a lot of armor plating to be had to avoid the whole issue.

And losses won't be higher, because the actions will be fought by smaller groups: the Moon won't have enough people to start anything on the scale of World War II for a very very very long time.

And did I mention that because the Moon is at the top of the hill, the colonists can attack the Earth simply by rolling rocks down on them? The war is extremely costly for the Earth, and fairly cheap for the Moon.

Oh, and on subject: SSTO RLV around 2010, permanent stations around 2015, lunar missions around 2025, lunar spaceport around 2045, Mars mission around 2060. That's the pessimistic view.

SSTO RLV 2008, stations 2010, lunar missions 2015, spaceport 2020, Mars mission 2025-2030. That's the optimistic view.

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Post    Posted on: Wed Aug 18, 2004 8:50 am
SSTO RLV 2008? Only 4 years from now?

Optimistic though I am, even the pessimistic date of 2010 seems a little early given the current state of play. Who would be your guess for the group/design for this?

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Post    Posted on: Wed Aug 18, 2004 9:22 am
Hello, spacecowboy,

in the case of a war earth against moon you may be right - I would have to think about it.

That wasn't what I had in mind - an earth-moon-war from my point of view is a quite different thing compared to a war between countries for special sites at the moon - stations, fabrics etc. - or the moon itself. This last was what I've been thinking about - "defending the moon" in the sense of "defending one country's claim of lunar ownership against another country's claim of identical lunar ownership" but not "defending the moon itself".

But theoretically the rivals may fight on the moon as well as on the earth and the one rival might attack the other sending military crafts from moon to earth. This would be similar to Napoleon III. fighting the war of 1870 partially in Mexico by trying to establish Emperor Maximilian I..

However removing military crafts from the moon might mean a disadvantage - the goal is to hold the site on the moon and to to give it up. It might prove be an extremely more difficult war - especially if now this seems to be a war in three dimensions whereas wars on earth ever have been wars in only two dimensions...! (Compare it to threedimensional chess which I never have tried yet.)

Underground settled colonies etc. - concerning the war this even might be prohibiting wars on the moon: a rival only is able to attack the other if he can reach him by weapons. So the fortifications required because of space, radiation etc. will make attacks and weapons useless - this is to be added to other obstacles for lunar wars.

It is a compicated and widespread thing - sorry if I've caused another misunderstanding.

But what about extending the timetable to more than only when what distance will be reached?



And why not 2008? The news concerning Scaled Composites assumed orbit intentions at least ar indicating that orbit might be reached until 2008 - may be not by SSTO. But I consider orbit more essential than SSTO.



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Post    Posted on: Tue Aug 31, 2004 3:15 pm
Maverick,
> Space elevator: 2050 - ?
> First spacecraft (unmanned or manned) with antimatter propulsion: 2050 - ?

Same year for a relatively easy versus relatively hard technology? I'd bump the space elevator to somewhat earlier (sometime before 2050), but bump the antimatter propulusion a few centuries away. Antimatter's just a bit too difficult to contain in large amounts, and the fuel needed for a fast intersteller journey could easily vaporize a whole planet Earth upon containment failure if it happened nearby. Risky, risky, risky, even if it could be done. I'd guesstimate Year 2500 or 3000 for antimatter; nuclear fusion propulusion would be much safer. They are making strides in antimatter manufacture and containment and some small engines might be possible by 2050 but I doubt it would be beyond solar-system roaming levels or even merely attitude control microthrusters and that can be done more cheaply using other technologies (ion/plasma based engines, fission, etc) Just don't count on antimatter quantities useful for interstellar journies, since an accident would be worse than all the bombs (existing, exploded, and unexploded, nuclear and non-nuclear) in Earth's history combined. All it takes is turning off the electric power and you've got instant containment failure; goodbye Earth. You'd want to go to outer solar system (possibly beyond Pluto) before you want to build an interstellar antimatter engine, and we've got a lot to do before we get that far. Let's say nuclear fission thrusters -- 2050. That's more realistic.

The space elevator comes way before antimatter propulusion. You only need 20 tons of high quality carbon nanotube ribbon rope (less than a kilogram a kilometer!) for a starter 60,000 thread that you build upon (suspension-bridge-style), and that can be launched using one heavy lift launcher today. Spinning earth swings the ribbon taut with centripetal force that overcomes the gravity (because some of the mass of the ribbon is above geostationary where the outwards pull is greater than gravity), and the physics are far simpler than antimatter engines and even nuclear fusion. They are already testing lots of the technologies required for an elevator today, and private companies as well as governmental (NASA) is now funding work on this. Goodbye to yesterday's outdated science fiction concept of electromagnetic space elevators and fantasy views -- it's just a concept of a lightweight ribbon 'rope' with mechanical climbers now. (Thanks to carbon nanotubes, the only material strong enough for the tension of a space elevator ribbon/rope/cable.) Thanks to this, the space elevator is now easier and should be much cheaper to build than a Mars mission. Time will tell...

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Post    Posted on: Wed Sep 01, 2004 8:41 am
Concerning antimatter-drive or -engine - by physical law velocities equal to or greater than c are impossible. So the required time to reach Alpha Centauri will be at least 4,3 years - including the time required for acceleraition from zero to c it will be much longer.

By solar sail or pulsed fusion drives velocities up to 0,14c are possible. Okay - that's seven times longer than 4,3 to 5 years. But does that count? Does that really matter?

The crew of a manned spacecraft will be roundabout 30 years old at launch. They will have to spend several years in the Alpha Centauri system for profitability of a mission like that - and at earth much more years will have been going on if they'd traveled to the other system by velocities near c.

So it seems that it doesn't matter wether they keep to be young during the travel or spend yaers of their lifetime travelling through the space and stay buried in the other system one day - perhaps having created a colony there.

And noone knows wether there will be found quite new possibilities to travel through the space by physics and engineering during 500 years.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Thu Sep 02, 2004 12:41 pm
Interesting thread, but somehow people are skipping alot on stuff that will actually be economically beneficial to earth.
So, predictions on first demonstrations of beamed solar power, first exctracts of Palladium/Iridium/Platinum/Rhutenium extracted from NEOs or lunar-impacted asteroids ?

A couple relevant links:
http://www.wronkiewicz.net/ssp/index.php
http://www.google.com/search?q=mitsubishi+solarbird
http://www.permanent.com/m-1stmis.htm


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Post Re:   Posted on: Sun Feb 16, 2014 9:49 pm
Texan wrote:
30 TIMES!!!!!!!!!!!!!!!! ARRRRRRRRRRRRRG!!!!!!!!

I wonder how much money Paul Allen is willing to spend....

How do the smaller teams plain to get to orbit if it is that hard? Of course "some people" say space tourism will make 10 billion of the next ten years, so somebody should be able to scrape together the cash for an orbital flight.

Btw if you have to be going 7 times the speed why is it 30 times harder?

also is it REALLY 30 times harder?



I am pretty sure Mars could be reached with a two man crew in less than 335 000 000 usd spent on Moon missions.

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Post Re: Space Exploration Timetable?   Posted on: Thu Feb 27, 2014 12:14 pm
According to space reporter Jeff Foust, XCOR will be begin flight tests this year:

Khaki Rodway, XCOR: Lynx Mk 1 flight test program to start in 2nd quarter; low-altitude flight tests in 3Q, high-altitude in 4Q. #spaceuphou
https://twitter.com/jeff_foust/status/4 ... 1135677440

XCOR is having a Q&A, today, Thursday, Feb. 27, at 2pm eastern, 11am pacific time.

Post your questions on Twitter:

@XCOR: We're interviewing XCOR CEO @jeffgreason for our blog tomorrow at 11 AM Pacific time. Have questions? Reply right here.
https://twitter.com/xcor/status/438856369320382464

Or on their Facebook page:

XCOR Aerospace.
We're doing a Q&A with XCOR CEO Jeff Greason for the XCOR blog tomorrow at 11 AM Pacific time. Have questions? Drop them right here.
https://www.facebook.com/xcoraerospace? ... n=timeline

Bob Clark

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Post Re: Space Exploration Timetable?   Posted on: Thu Apr 17, 2014 7:12 pm
The lesson of history in spaceflight is this: The most important advances appear to come out of nowhere, creating awe and hyper-optimistic projections among the public and media, but are then followed by long periods of seemingly no progress while the economy catches up with the potential.

These periods create frustration and disaffection that drive the next round of advances, which also appear to come out of nowhere to the casual observer. In other words, progress in space has a pattern of taking ten steps forward then eight steps back: Radical lurches forward, then stagnation and backsliding, then the cycle repeats.

As much as SpaceX talks about reusability and Mars, and as credible as they're considered, it will come as a massive shock to the world when they actually start delivering on their plans. The first time one of their Falcon 9 first stages lands back on the launch pad, the internet will explode and people will assume we're a couple of years away from Star Trek. But then the arduous task of building it forward and dealing with setbacks will unfold, and people will calm down, maybe even get frustrated that (inevitably) it will not be utilized to its full potential.


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