photovoltaic panels propulsion into space

[Brusca]

Hi,


I'm asking for a possible photovoltaic panels propulsion into space.

My question is can electric enigines propel into space?
Phisically if a wheel runs on another wheel and viceversa then can they propel?


Thanks

 

[MeteorWayne]

Huh?

First of all, this doesn't belong in Phisics (sic) so will be moved.

Second, are you suggesting that photovoltaic panels can provide enough thrust to lift off from the earth's surface? That's just silly. It's not realistic within several orders of magnitude.

 

[Brusca]

Huh?

First of all, this doesn't belong in Phisics (sic) so will be moved.

Second, are you suggesting that photovoltaic panels can provide enough thrust to lift off from the earth's surface? That's just silly. It's not realistic within several orders of magnitude.

I just need some physics opinions about that.



Thanks

 

[MeteorWayne]

About what??

 

[origin]

Rephrase the question and be more specific.

I predict however, that the answer is no.

I am such a curmudgeon...

 

[Brusca]

Origin, do you think you are right?

You are only a simple {bypass of profanity filter deleted}... :shock:


I need some physics opinions about
if a wheel runs on another wheel and viceversa, can they propel into space?


Thanks.

Pease, i don't want opinions from the {bypass of profanity filter deleted} origin....

 

[Jazman1985]

It's understandable if someone such as yourself has a very limited knowledge of physics, such that you even need to ask the question of whether photovoltaic cells can propel an object into space. However, even with limited knowledge of physics, some people can still be considered to be intelligent. Calling a member of a public forum a {bypass of profanity filter deleted} when he attempted to answer your question, and granted, me not having any prior knowledge of any relationship between you and origin which would enable this term to be interpreted to be used in jest, I have to assume that whoever is asking the questions is a moron. Please use common decency when asking questions, this may help you not get the {bypass of profanity filter deleted} beat out of you in life.

To answer the question, I assume you are implying some type of machine that would use a solar cell to turn an electric engine which could propel a ship or object into space. In the atmosphere, a motor(presumable with a turbine or propellor on it) has something to push against(air). Every action has an equal and opposite reaction, so when you push against air the craft moves forward proportional to the air mass and speed moved backwards. What would a propeller(or a wheel) push against in space? It has to create thrust by accelerating a particle backwards through a rocket.(can be either chemical or electric rocket) The amount of thrust created by this is miniscule compared to the energy put into it. While in space, because there is no air resistance, something such as VASIMR or an Ion engine could accelerate a craft, but it is something like 10,000 times too low of a thrust to accelerate a craft to orbit. Photovoltaic cells could simply not generate enough energy to lift a craft into orbit, even with 100% efficiency they wouldn't be close.

 

[origin]

Origin, do you think you are right?

You are only a simple {bypass of profanity filter deleted}... :shock:


I need some physics opinions about
if a wheel runs on another wheel and viceversa, can they propel into space?


Thanks.

Pease, i don't want opinions from the {bypass of profanity filter deleted} origin....

Well!

My opinion, wanted or not, is that you are potty mouth....

 

[Brusca]

Origin is the last person I would want as a friend !...
It seems I'm speaking martian.


I said two wheels are running one on other.
The friction needed to propel is given from the other wheel and viceversa.

I hope that someone can give me an opinion about this friction.

 

[origin]

Edited: to delete the post as it was basically for no other reason than to antagonize....

 

[michaelmozina]

Hi,

I'm asking for a possible photovoltaic panels propulsion into space.

A photovoltaic panel is typically incapable of producing enough total energy to lift itself into orbit, let alone lift additional materials into orbit. It simply doesn't produce enough energy to do that. It can produce *SOME* energy, but not nearly enough to put itself into orbit.

My question is can electric enigines propel into space?

Possibly. There are plasma rockets that essentially eject materials and create push using EM propulsion. They typically do are not used as lift vehicles because they cannot produce an initial lift that can get them into orbit, but they can run for a long time and thereby increase the speed over time once they are in orbit. They don't current produce enough lift to get themselves into orbit, but in theory *SOME* EM propulsion design might.

http://www.gizmag.com/ad-astra-ion-engi ... ays/12342/

Phisically if a wheel runs on another wheel and viceversa then can they propel?

Thanks

Probably they wouldn't propel anything other than perhaps spin the other wheel and they (collectively) would loose energy to friction over time.

 

[drwayne]

As president of the very slow physicist's club, I would like to ask a couple of stupid questions:

(1) Is the system you are proposing for use in booster / liftoff functions, or for thrust "in space"?

(2) How exactly are you using the wheels that you refer to? As power storage, or as some form of mass driver?

I would encourage you to take your time and try to be complete as possible - there are a number of professionals
in the propulsion field here who know their stuff and can probably be very helpful, given a good understanding
of the proposed solutions.

Wayne

 

[Brusca]

You are saying the friction wheel-wheel cannot produce thrust in space(when the two wheels are running).

Is it true?

How can you explain it to me phisically?



Thanks

 

[drwayne]

Since I (and I suspect others) are unclear what you mean by a friction wheel drive as applied
to a space vehicle, it would probably help if you take some time to describe what you mean by that.
By what mechanism is thrust generated?

Wayne

 

[Fallingstar1971]

OK let me understand........

You have two wheels (perhaps a wheel inside of a wheel?) (forgive the pun)

You want to use one, to spin the other, to provide energy for thrust.

Problem is, what form of energy are we producing?

Electrical would mean that at least one of your wheels would need to be connected to a generator, the other will require a mechanical force to spin it.

Without perpetual motion, you will never get the same energy output as input. In other words, you will not get more energy OUT of your system then what you put IN to your system.

So now I need to ask, what force is causing your wheels to spin? Theres your energy input.

Of course I could be seeing this all wrong. You may be implying that two GEARS linked together and spinning would cause some kind of propulsion, In which case I would have to say no. You have no way of converting the mechanical energy into propulsion. You have no prop (no air, no water) The gears pushing on one another, the harder they push, the more energy required to turn them, the more energy lost in friction. (what I mean by this is total energy loss in your system as a whole. Those gears are connected to something, each moving part take a little more energy away until your output force + your energy loss = total STARTING energy)

I suppose there COULD be a slight "wobble" in your craft due to momentum,(two objects spinning) but even still there are TWO gears turning in OPPOSITE directions, their momentum SHOULD cancel each other out.

Of course if you FEED the two gears so that they shoot particles out of one side, THEN you could move, but consider the energy LOSS from the two gears working to force these objects through them. (mechanically, your gears will wear down because of friction, these "worn" particles of metal (or whatever) would be ejected causing a very SMALL movement, but nothing practical enough to travel anywhere, with pratically NO efficiancy.)

Thats my take on it anyway. If you want someone to do the math for you tho your SOL unless someone else here is feeling "mathy" and wants to work out the equations for you. But logic states that you will never, never get 100% or more energy output. (unless you have a frictionless ballbearing, that alone would change EVERYTHING!)

Star

 

[Brusca]

Thanks for your interest!!!...


Only solar photovoltaic panels gives electric engines the power to spin the couple of wheels...


Mathematically we have to calculate if the friction wheel-wheel is good in order to have a good propulsion into space.
Intuitively it seems that these couple of wheels have to accelerate if they have the same rotational speed(in order to have friction for propelling).
Phisically it's better to know opinions at first !

 

[MeteorWayne]

You still have yet to make any effort to explain how your spinning wheels provide propulsion. You know, the old f=ma thing....

 

[Shpaget]

I think he thinks the wheel on wheel system is positioned in this position (now that's a lot of repetitious repetition :lol: ):
OO
The energy to spin them is provided by electric motor driven by photovoltaics (but it could in fact be provided by any kind of electricity generating equipment, PVs are not part of propulsion system).

Let's say the left wheel turns clockwise and the right counterclockwise (they are in contact). The friction force would act in the direction of the arrow:
OˇO

I think he thinks that force would propel the craft in the space.
However, he doesn't include the reaction forces on the outside of the wheels:
^OˇO^

So, the answer is: No.
You can not produce propulsion without some kind of reaction mass that is "thrown away" in the direction opposite of the desired travel direction.

 

[undidly]

Put the friction wheels one on each side of the space elevator cable (when and if it gets built).
Drive both wheels very geared down so they rotate only slowly but with enough torque to drive the weight of the motors and photo cells up the cable.
Keep going up to geosynchronous distance (so it cannot fall back)then disconnect from the cable and switch to electric ion drive or even use the solar cells as solar sails to spiral away from Earth.
For more thrust use the back of the solar cells painted white or silver.

 

[Shpaget]

Just one problem... there is no space elevator

 

[undidly]

http://www.youtube.com/watch?v=2ABVGHyp ... _embedded#

http://www.popsci.com.au/technology/art ... -beam?page

 

[origin]

http://www.youtube.com/watch?v=2ABVGHypirQ&feature=player_embedded#

http://www.popsci.com.au/technology/art ... -beam?page

I made it through almost a whole minute before I got board with watching a guy standing next a little contraption.

 

[Shpaget]

And the Oscar for the crappiest picture goes to the unnamed hero holding a 3 fps camera...

Is that thing lifted by the helicopter? Looks that way to me.
Extraordinary feat of modern engineering.

 

[undidly]

And the Oscar for the crappiest picture goes to the unnamed hero holding a 3 fps camera...

Is that thing lifted by the helicopter? Looks that way to me.
Extraordinary feat of modern engineering.

It is climbing the rope under the helicopter,but it is a poorly organized demonstration.

It should climb a rope off the side of a building.
The rope could be 10000 feet long and slowly lowered as the climber went up.
Or twice as long as the building is high and joined into a circle.Measure how much rope it climbs.
That would test how far it could go.