Space travel is a dream…no..myth! Impossible!

[xav0989]

With the current laws of quantum physics, we could not separate an thing atom by atom to recreate it at the destination. We would need another Einstein to bring forward new theories in physics.

 

[wolflock]

Most here speak as if we have discovered All there is to discover when it comes to science, space and travel. Good to see some of you have keen site about our advances in science.

 

[hot100]

Advancement in science is still very young.

However, when you talk about it catapulting in the next 500 years, that may be hard to imagine. Right now, all technology is based on electromagnetism.

Until we discover another means to create and control other than the use of electrical charge and magnetism, I think our science will pretty much be limited.

We need a new form of control in order to see that jump in technology.

 

[compass]

Actually the Higgs boson may have a bearing on space travel.
It is assumed it gives mass.

Mass means inertia. Mass means you need an infinite amount of energy to reach light speed.
It also means humans would get squashed by an acceleration of more than 30-40 Gs, which means (even assuming a lot of free/cheap fuel) it would be really sloooowww to reach great speeds.

But for true, extra solar system travel, we will need FTL. Be it an "engine" or wormholes or some form of "teleportation". Otherwise you cannot call it travel.

And as for the questions of "should we even try when we have so many problems here...", well, we should try it because we have these problems.

If nothing else, a more rapid expansion in near space (say Moon - Mars, no more than that), would give us some capability to defend against a "dinosaur killer" asteroid/comet strike.

Dream yes, impossible no!

 

[hot100]

...Be it an "engine" or wormholes or some form of "teleportation".

Now that's an idea. 'Teleportation' could seem like the best way to travel to incredibly distant places in a very short time.

A question arises however, where would you be teleporting to? You need to know the point of re-assembly to avoid teleporting into other forms of matter or just utter nothingness.

Considering that light doesnt travel fast enough to satisfy our need for space travel, it would still take years to get images of your target destination.

Figure out the the rest....

 

[dharshan]

yeah, It would be a dream that we will never fulfill. look at all these years they have spent after the moon exploration in 1969. NASA have not gone far than that with human space travel. and as I think some thing will happen around 2012.......I agree that it's gonna be just a dream!

 

[cybrax]

It's not the fault of science that space travel hasn't got off the ground in a big way all the math is well understood, propulsion technology is more than up to the task as is enclosed life support systems.

Of course you don't believe me, so here's some things to chew on..

Check out the 'Orbiter Flight Simulator' it is a free download, [SIZE=-1]the Delta Glider is particulary interesting. Uses real world physics and engine specs to create a Single Stage To Orbit vehicle.

Back in the late fifties Atomic power was heralded as the way into space and if the engine test results for the NERVA project are anything to go by then you could pretty much put anything into orbit and beyond.

Add to that the work of the USAF (Russia & Britain had similiar projects) and its Atomic Powered Flight project where they shoe-horned a working fission reactor into a bomber to provide propulsion and it all starts to come together.

Side note: Anybody remember the TV show Captain Scarlett or Thunderbirds in particular?
All of the big aircraft were Atomic powered.

What went wrong, Why did we fall out of love with the warm cosy glow of Atomics?

[/SIZE]

 

[ah-blabla]

Nuclear power in a space rocket? There is no way that would be allowed: as you may know one of the main problems with nuclear power (fission to be exact) is waste products, and where to put them. There was the rather obvious idea of ejecting them to space. How? With a rocket. Why was this not taken up? The great dangers of a rocket malfunctioning just after launch, exploding, and the resulting radiation spread over a large area of the world...

And nuclear power only provides electricity (actually heat to be more precise, which is then usually converted). Ever seen an electric powered rocket? (Ok, it is possible to do a space shuttle on Jumbo Jet style launch, i.e. as an aircraft turning to space vehicle, but the chances of that being approved are also low, as well as the practical problem of needing much more time to get out the atmosphere.) The main problem is that there is no propulsion method which can use electricity for space travel. You can use propellers in fluids such as air/water (i.e. what 'planes and ships do), but in vacuum that's useless.

The NERVA (Nuclear thermal rocket) method, which uses a nuclear reactor to heat a propellant for propulsion is also not that amazing, and when NERVA was abandoned, it was still less effective than chemical engines. Maybe it could be improved, but it would hardly bring much more than a chemical engine; it's theoretical limit isn't amazingly greater than chemical engines.

The reason the space race is over is since we no longer have the cold war, which was the main driving force for it all. Space travel is expensive, uneconomical, and more importantly, useless. There is little benefit to be had from space travel for humanity.

 

[cybrax]

I expected some fall out..

but "NERVA less effective than chemical rockets" ? I better not mention the specific impulse figures from the NASA website then. Or the fact that the only chemical propellent combination that comes anywhere close to being as efficient is Ammonia+Flourine and yes the exhaust gas of that mix is very toxic, NERVA by contrast could just run on water and emit superheated steam.

And..
What does flight time to orbit matter for a vehicle that can remain airborne in an atmosphere for years?


I did think long and hard however about a "propulsion method which can use electricity for space travel" I discounted ION & microwave propulsion on the grounds it expended fuel though you could argue a boat also expends fuel to turn the propeller.

But I think I understand the point you are trying to make and there is a way of moving a spacecraft using electrical energy without expending propellent.
It's called the Magneto Plasma Sail...

I did think of mentioning the work of the late Professor Eric Laithwaite and his Reactionless Gyroscopic Thrusters but I save that particular topic for tormenting engineering students because the Math is a little more advanced than many can cope with.

"little benifit to humanity" is a pretty bold statement after all some of us stuck here are not happy with the way the place is run and would like to get off planet as soon as posibble before 'humanities' lease expires.

 

[ah-blabla]

I expected some fall out..

but "NERVA less effective than chemical rockets" ? I better not mention the specific impulse figures from the NASA website then. Or the fact that the only chemical propellent combination that comes anywhere close to being as efficient is Ammonia+Flourine and yes the exhaust gas of that mix is very toxic, NERVA by contrast could just run on water and emit superheated steam.

Well, I read this which seems optimistic actually. However on wikipedia I notice the sentence "test engines themselves never managed to produce more than 40% of their theoretical thrust, which made them less powerful than contemporary conventional rocket engines." It seems various sources are in dispute

And..
What does flight time to orbit matter for a vehicle that can remain airborne in an atmosphere for years?

Only problem human lifespan is limited :happysad:. But in the future, who knows how long we will live.

I did think long and hard however about a "propulsion method which can use electricity for space travel" I discounted ION & microwave propulsion on the grounds it expended fuel though you could argue a boat also expends fuel to turn the propeller.

But I think I understand the point you are trying to make and there is a way of moving a spacecraft using electrical energy without expending propellent.
It's called the Magneto Plasma Sail...

I did think of mentioning the work of the late Professor Eric Laithwaite and his Reactionless Gyroscopic Thrusters but I save that particular topic for tormenting engineering students because the Math is a little more advanced than many can cope with.

"little benifit to humanity" is a pretty bold statement after all some of us stuck here are not happy with the way the place is run and would like to get off planet as soon as posibble before 'humanities' lease expires.

Actually, I must admit I was being too sceptical. Ion propulsion might actually be feasible, it does use fuel, but much more slowly, albeit with lower propulsion. A reaction-less drive though is physically impossible (unless our Newton was wrong). Rather interesting is a Magnetoplasmadynamic thruster. That might be a feasible technology in the future. However it will take ages to get all the technology, such as safe nuclear power, good propulsion mechanisms etc.

So, I do believe we will be able to get proper space travel on the go. The time-scale until that happens though is pretty large. We, I am sure, won't live to see that day - I'd put it at maybe 500 -1000 years until we might start sending humans to the edge of the solar system. (And any such travel, i.e. even to another solar system, is a very serious undertaking: it even takes years just to get to Pluto.)