Why are we still using rockets?

why rockets?

because we know they work, they are (realativly) cheap, easy to build and launch

anything important that needs to get up safetly will be launched by a normal rocket, at least for now

when the funds are "spare" for pure testing of new propulsation, then it will happen soon

of course just like when rockets came in, when that new tech finally happens, there will be a instant boom of new tech and stuff will happen fast again, thats just how technology evolves, a new thing comes along, then it gets squezed for as much as possible untill a "new" big thing happens

which i believe will be here by 2015, whateva it turns out to be

Originally posted by fiftyfifty
Do we need to launch into space at high speed? how about using hydrogen as a light gas to reach the atmosphere, then burning the hydrogen in a controlled way to reach orbit. Im no astronaut but it sounds good to me! how much hydrogen would you need by the way? I know its dangerous but so is rocket fuel. Even if it took a day to reach orbit wouldnt the cost cutting make it worthwhile?

Or am i talking BS...

We need to achieve "escape velocity", the velocity that an object needs to reach to escape a gravitational field.

At the Earth's surface this speed is 11.2 km/s, and even the rockets that are launched into space are unable to reach that velocity in the atmosphere.

So, they only reach escape velocity when already outside of the atmosphere, so they already do more or less what you talked about, the difference is that if they got out of the atmosphere at low velocity then they will need a stronger acceleration, so they probably are using already the most efficient method.

Originally posted by ArMaP

Originally posted by fiftyfifty
Do we need to launch into space at high speed? how about using hydrogen as a light gas to reach the atmosphere, then burning the hydrogen in a controlled way to reach orbit. Im no astronaut but it sounds good to me! how much hydrogen would you need by the way? I know its dangerous but so is rocket fuel. Even if it took a day to reach orbit wouldnt the cost cutting make it worthwhile?

Or am i talking BS...

We need to achieve "escape velocity", the velocity that an object needs to reach to escape a gravitational field.

At the Earth's surface this speed is 11.2 km/s, and even the rockets that are launched into space are unable to reach that velocity in the atmosphere.

So, they only reach escape velocity when already outside of the atmosphere, so they already do more or less what you talked about, the difference is that if they got out of the atmosphere at low velocity then they will need a stronger acceleration, so they probably are using already the most efficient method.

"Escape Velocity" is only required to "escape" the gravitational pull of a celestial body if your intention is to leave the gravitational well of that body. For example, if you were to attempt to fly to another planetary body.

Otherwise, all you require is "Orbital Velocity" to achieve/maintain a stable orbit about the planet/body.

And niether Orbital velocity nor Escape velocity Must be achieved Prior to reaching operational altitude; the consequnce of failing to achieve orbital velocity (the lower of the two) is merely a ballistic flight trajectory, as demonstrated by artillary shells and "sounding" rockets.

It would, in fact, be much more efficient, and desirable, to utilize your precious and limited fuel to achieve the required velocity once your were unencumbered by the viscous effects of the atmosphere; if you could somehow rise above the atmosphere without burning a large portion of your fuel to get there.

The "danger" posed by Hydrogen has been seriously over-hyped, in my opinion. Vaporized gasoline is every bit as potentially explosive as hydrogen, yet we depend on it to fuel our vehicles (it's gas vapor that gets injected into the cylinders of the engine, after-all!). Being lighter than air, after all, when ignited, hydrogen will naturally rise as it burns, up, and generally away from, anyone near the ignition point.

The true obstacle to using bouyancy instead of "Boom" to get us into space lies in material science. There just does not seem to be a readily available material that is both light weight enough and strong enough to contain the amount of "lift gas" we would need to "float" to space.

But that may change, hopefully, Soon!

Without reading this entire thread, we're still using rockets because they cost a ridiculous amount to develop, and getting any new propulsion tech to that level likely be similar. Remember, these things took decades of extremely capital intensive research to get to where they are today, and they were additionally(primarily?) subsidized by the need to develop the technology for long-range missiles in the Cold War. There is no such impetus for a new tech.

[edit on 10-7-2006 by b_selig]

Originally posted by ArMaP

Originally posted by razor1000
We've been in space now for almost half a century and yet we are still using rockets WTF, when airplanes were invented they evolved overnight.

The first airplanes were made by private individuals making their own research. The making of an airplane was a task that was within the reach of the technology and funds those individuals could get.

The same thing happened with the rockets, the first experiments were made by some people trying something new, but the difference is that a rocket, to be able to transport anything useful, is too expensive to be built by some guy doing research.

Also, airplanes had a good reason to evolve, called World War I. At the time rockets were useless as a weapon, so they did not evolve.

In World War II they were used as a weapon, and todays rockets are just a step over those rockets. Even WWII rockets were too expensive, and they were only built because they could be used in the war.

Also, the Earth's gravity is too strong to use some of the other known propulsion methods.

Also, some of the methods that could be used are really useless because of the acceleration they provoke is too high, like in the Jules Verne story where they are shot from a canon.

okay so what you're saying is that its going to take an invasion from outer space or a meateor heading for us to make our tech get a quantum leap

Originally posted by razor1000
okay so what you're saying is that its going to take an invasion from outer space or a meateor heading for us to make our tech get a quantum leap

No, I am not saying nothing like that.

If you are invaded by aliens from outer space I do not think that our rockets could evolve quickly enough, in WWI the evolution was from both sides, starting from known common types of aircrafts, and I do not think that would be the case if we were the victims of an invasion from outer space.

If a meteor is heading towards us, some arithmetic will show you that we wouldn't have time for making anything useful.


What I was trying to say is that the type of technology involved in the making of a machine capable of at least orbital flight is outside the reach of the common industries and individuals.

For example, it is easy to use a wind or a water mill to make electricity, but it is much more difficult for someone to make a nuclear power plant.

Originally posted by Bhadhidar
It would, in fact, be much more efficient, and desirable, to utilize your precious and limited fuel to achieve the required velocity once your were unencumbered by the viscous effects of the atmosphere; if you could somehow rise above the atmosphere without burning a large portion of your fuel to get there.

OK, now I understood it better, I should have been half a sleep when I read the other post.

Originally posted by Bhadhidar
The "danger" posed by Hydrogen has been seriously over-hyped, in my opinion. Vaporized gasoline is every bit as potentially explosive as hydrogen, yet we depend on it to fuel our vehicles (it's gas vapor that gets injected into the cylinders of the engine, after-all!). Being lighter than air, after all, when ignited, hydrogen will naturally rise as it burns, up, and generally away from, anyone near the ignition point.

Hydrogen is the best fuel, and the risk lies in the great quantities needed. But if it goes to explode, any fuel is dangerous enough.

Actually, there are a ton of different methods of propulsion.. many of them are still in their infancy.. Here's a list..

Mechanical Sources

Compressed Gas
Potential Energy
Kinetic Energy

Chemical Sources

Fuel-Atmosphere Combustion
Fuel-Oxidizer Combustion
Chemical Battery

Thermal Sources

Heated Storage Bed
Concentrated Sunlight

Electrical Sources

Power Line
Circulating Electron Storage
Magnetic Storage
Photovoltaic Array
Solar-Driven Turbine/Generator
Microwave Antenna Array

Beam Sources

Laser
Microwave
Neutral Particle

Nuclear Sources

Radioactive decay
Nuclear Fission
Nuclear Fusion
Nuclear Explosions

Matter Conversion Sources

Antimatter
Quantum Black Hole


Suggested Reading Material:

Anonymous "Conference Record of the Nineteenth IEEE Photovoltaic Specialists Conference- 1987", New Orleans, Louisiana, 4-8 May 1987.

Anonymous "NASA Conference Publication 2475: Space Photovoltaic Research and Technology 1986: High Efficiency, Space Environment, and Array Technology", Cleveland, Ohio, 7-9 October 1986.

Chubb, Donald L. "Combination Solar Photovoltaic Heat Engine Energy Converter", Journal of Propulsion and Power, v 3 no 4 pp 365-74, July-August 1987.

Spielberg, J. I. "A Solar Powered Outer Space Helium Heat Engine", Appl. Phys. Commun. vol 4 no 4 pp 279-84, 1984-1985

Lockwood, A.; Ewell, R.; Wood, C. "Advanced High Temperature Thermo-electrics for Space Power", Proceedings of the 16th Intersociety Energy Conversion Engineering Conference, v 2 pp 1985- 1990, 1981.

El Genk, M.S.; Hoover, M. D. "Space Nuclear Power Systems 1986: Proceedings of the Third Symposium", 1987.

Bloomfield, Harvey S. "Small Space Reactor Power Systems for Unmanned Solar System Exploration Missions", NASA Technical Memorandum 100228, December 1987

Miley, G. H. et al "Advanced Fusion Power: A preliminary Assessment, final report 1986-1987". National Academy of Sciences report #AD-A185903, 1987.

Eklund, P. M. "Quark-Catalyzed Fusion-Heated Rockets", AIAA paper number 82-1218 presented at AIAA/SAE/ASME 18th Joint Propulsion Conference, Cleveland, Ohio, 21-23 June 1982

Hora, H.; Loeb, H. W. "Efficient Production of Antihydrogen by Laser for Space Propulsion", Z. Flugwiss. Weltraumforsch., v. 10 no. 6 pp 393-400, November-December 1986.

Forward, R. L., ed. "Mirror Matter Newsletter", self published, all volumes, contains extensive bibliography.

Space Transport and Engineering Methods
Propulsive Forces
Wiki: Spacecraft Propulsion
Nanotechnology Propulsion
The Journal of Advanced Propulsion Methods
Advanced Concepts in Space Propulsion
Future Fusion Propulsion
Propulsion for Interstellar travel

My 2 cents.

The only place i've ever seen that was on the movie event horizon. i seriously doubth that the scientists are messing with that kind of power. for one it would require so much energy to power it that today we dont have that kind of resource, second if they were and they had a runaway we'd all be royally screwed. please set a link to this i'd like to read more about it though.

Originally posted by razor1000
...for one it would require so much energy to power it that today we dont have that kind of resource, second if they were and they had a runaway we'd all be royally screwed. please set a link to this i'd like to read more about it though.

Hence why such a technology would be considered "still in development."

On top of that, I fail to see how we would be "royally screwed" by this technology if something goes wrong. Quantum black holes are just that, on the quantum level... Not some giant enveloping all matter that comes its way.

Originally posted by razor1000
Please set a link to this i'd like to read more about it though.

Basic Physics of Black Holes
CERN plans to make Black Holes
More

This method is still very much in it's infancy.. but scienctists beleive they can harness the event horizen (Singularity Propulsion) of a black hole to form Kinetic Energy

I'm not too informed on this research, it's still in "theory".. so it's not even proven

You can gain kinetic energy through the Penrose process from a Kerr black hole. That would involve dropping to the black hole some ballast in such a way that the kinetic energy of the ballast would be negative. This condition can only be satisfied in the ergoregion and the result would be for the \"space ship\" to gain kinetic energy.

There is a constrain to this process and it has to do with the amount of energy you will try to extract. It shouldn\'t be so grate that would effect the properties of the black hole significantly. In other words the process works in an effectively unperturbed spacetime.

There is also a constrain on the total energy you can extract. You can\'t extract all the energy of the black hole in that process. There is a minimum mass that the black hole can have and that is the irreducible mass as introdused by Christodoulou.

www.advancedphysics.org...

Originally posted by porky1981
as I posted in another thread, I don't think it is wise to put a bunch of uranium/plutonium and other fission products up into space. A re-entry accident would send all of the nuclear material into the atmosphere....so the old saying goes 'don't sh*t in your own backyard..'.

Now, the real question should be...why do we still use cars!?? It has been a hundred years and we still rely on the combustion engine for transportation, etc.., it is pathetic. There are so many patents and ideas out there that are silenced so that outdated technology remains and the companies that rely on them swell with cash....

I can't wait until we get our jetsons cars...

Yeah, I saw the flying car patent. Only way I find it to be safe if these new flying cars would fly along desginated paths that can't be altered by the driver/pilot. I would not want to have a flying car crash into my home or anyone elses for that matter.

But that kind of technology would make driving not fun at all. Hop into your flying car to read a book while the computer plans out you commute. Boring.
Really would make you miss having contorl of the vehicle.

As for rockets that seems to be the best choice now, maybe in another 100 years this might change who knows. Not all technologies progress at steady paces others do i.e. computers, break throughs need to be made.

What bothers me - 2 things.
1. If we (our government) really got space technology from crashed saucers, then WHY DO WE CONTINUE to send our astronauts in shuttles that are out-of-date?
2. If they really did get info from crashed saucers, then WHY didn't they improve the OUTSIDE COVERINGS of the shuttles? As an ET, the spaceships I have seen had biomechanical coverings. They were not patch jobs, held together with rivets, with problems of FOAM falling off!
Do the astronauts realize that they are being sent up in vehicles which are less safe, just so the public won't know that the government can do better?

Originally posted by cmdrkeenkid

Originally posted by razor1000
...for one it would require so much energy to power it that today we dont have that kind of resource, second if they were and they had a runaway we'd all be royally screwed. please set a link to this i'd like to read more about it though.

Hence why such a technology would be considered "still in development."

On top of that, I fail to see how we would be "royally screwed" by this technology if something goes wrong. Quantum black holes are just that, on the quantum level... Not some giant enveloping all matter that comes its way.

Easy now amigo dont bite my head off, i dont know much about it but thats the first thing that pops into my mind when someone says black holes.

Originally posted by QuietSoul

Originally posted by razor1000
Please set a link to this i'd like to read more about it though.

Basic Physics of Black Holes
CERN plans to make Black Holes
More

This method is still very much in it's infancy.. but scienctists beleive they can harness the event horizen (Singularity Propulsion) of a black hole to form Kinetic Energy

I'm not too informed on this research, it's still in "theory".. so it's not even proven

You can gain kinetic energy through the Penrose process from a Kerr black hole. That would involve dropping to the black hole some ballast in such a way that the kinetic energy of the ballast would be negative. This condition can only be satisfied in the ergoregion and the result would be for the \"space ship\" to gain kinetic energy.

There is a constrain to this process and it has to do with the amount of energy you will try to extract. It shouldn\'t be so grate that would effect the properties of the black hole significantly. In other words the process works in an effectively unperturbed spacetime.

There is also a constrain on the total energy you can extract. You can\'t extract all the energy of the black hole in that process. There is a minimum mass that the black hole can have and that is the irreducible mass as introdused by Christodoulou.

www.advancedphysics.org...

Thanks for the link it should make some interesting reading.

Originally posted by Imzadi
What bothers me - 2 things.
1. If we (our government) really got space technology from crashed saucers, then WHY DO WE CONTINUE to send our astronauts in shuttles that are out-of-date?
2. If they really did get info from crashed saucers, then WHY didn't they improve the OUTSIDE COVERINGS of the shuttles? As an ET, the spaceships I have seen had biomechanical coverings. They were not patch jobs, held together with rivets, with problems of FOAM falling off!
Do the astronauts realize that they are being sent up in vehicles which are less safe, just so the public won't know that the government can do better?

Well i can only tell you what i've reasoned so far, but if you really want to know you should ask those guy that are deep into cover ups.
first ?- think about poker you can't show all your cards to your enemies or friends because they will use them against you
second ?- it goes back to the first question.
the astrnauts know the dangers its no secret they go because they want to be in space.