Reactionless Drive Systems.

CasualBystander

Celestial
Was looking at EMDrive and realized there is a range of Mach Effect Thrusters
Theoretical physicists get closer to explaining how NASA’s ‘impossible’ EmDrive works
Woodward effect - Wikipedia

The Woodward Effect is one potential Mach Effect Thruster.

The description has this interesting tidbit:
The mass of the electron is positive according to the mass–energy equivalence E = mc2 but this invariant mass is made from the bare mass of the electron "clothed" by a virtual photon cloud. According to quantum field theory, as those virtual particles have an energy more than twice the bare mass of the electron, mandatory for pair production in renormalization, the nonelectromagnetic bare mass of the "unclothed" electron has to be negative.[45]
 
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CasualBystander

Celestial
How are these devices powered ?

They would probably use electricity from solar panels or a nuclear reactor.

Just to note: the EMDrive is technically a Mach Effect Thruster. It uses RF (radiofrequency) EM radiation generated by electricity so any power source that generates electricity is OK.

What drives physicists nuts is they don't want to believe reactionless drive (Mach Effect thrust) is real.

The Mach Effect theory started from a "what if". If there is one object in the universe it doesn't have a defined mass or inertia since you don't know its velocity.
 
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3FEL9

Islander
The Mach Effect theory started from a "what if". If there is one object in the universe it doesn't have a defined mass or inertia since you don't know its velocity.

From ur wiki link:

** If we produce a fluctuating mass in an object, we can, at least in principle, use it to produce a stationary force on the object, thereby producing a propulsive force thereon without having to expel propellant from the object. We simply push on the object when it is more massive, and pull back when it is less massive. The reaction forces during the two parts of the cycle will not be the same due to the mass fluctuation, so a time-averaged net force will be produced. **

That explains it ? Just oscillate the mass of the object you are pushing/pulling against
 

CasualBystander

Celestial
From ur wiki link:

** If we produce a fluctuating mass in an object, we can, at least in principle, use it to produce a stationary force on the object, thereby producing a propulsive force thereon without having to expel propellant from the object. We simply push on the object when it is more massive, and pull back when it is less massive. The reaction forces during the two parts of the cycle will not be the same due to the mass fluctuation, so a time-averaged net force will be produced. **

That explains it ? Just oscillate the mass of the object you are pushing/pulling against

Well... lets take an example.

We add energy to an object. Push it. Let the energy dissipate, then stop it. The recoil (stopping) force is less than the initial push and the energy loss is omnidirectional (no net force).

The theory isn't the problem, it is building a system that uses the principle efficiently enough.

Just to note: a nuclear power system would drive other things and the excess power would be used for propulsion.

And you don't have to generate a lot of thrust.

A system that generates 1/1000th of rocket thrust gets to Mars in weeks instead of months.

Last time I computed this a couple hundred ton rocket could get to Mars in a couple of weeks with 20 kg of force.

200,000 kg payload, 20 N (kg/m*s*s) force, 54 million miles to Mars. D = 1/2 * a*t*t

12 days. Since you have to start slowing down a little beyond halfway it is about 18-20 days (you have to be going fast enough to make orbit on the far end).

For comparison: the S-IVB used to break earth orbit for the moon had a thrust of 901 kN.

The mission profile would look like a moon mission - with 20 N of thrust.

With aerobraking you could land something on Mars much heavier than the moon mission.
 
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3FEL9

Islander
20 kg or 20 N ? A factor of 10 in thrust difference,, which one did you use ?

Whats the exact formula ?
 

3FEL9

Islander
Whats the exact formula ?

I had to brush up on my knowledge.. This is the force in N for conventional rockets

rktthsum.gif
 
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CasualBystander

Celestial
20 kg or 20 N ? A factor of 10 in thrust difference,, which one did you use ?

Whats the exact formula ?

A Newton accelerates 1 kg 1 m per second per second.

A one kg weight at the earths surface in the Washington DC area exerts a force of 9.81 N on whatever is holding it up.

If a scale says you weight 86 kg, it is really measuring 843.66 Newtons and doing the math.

Measuring mass directly is far too expensive for a simple bathroom scale.


And the comparison was a 901,000 Newton rocket vehicle with a 475 second burn time that massed 115,000 kg for engine, structural components and fuel vs a 20 Newton reactionless propulsion system that can burn effectively forever that masses less than 100 kg. An empty can full of plastic foam and an RF generator is pretty light.

And the S-IVB only pushed about 46 metric tonnes of payload, not 200 metric tonnes.
 
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3FEL9

Islander
A Newton accelerates 1 kg 1 m per second per second.

A one kg weight at the earths surface in the Washington DC area exerts a force of 9.81 N on whatever is holding it up.

If a scale says you weight 86 kg, it is really measuring 843.66 Newtons and doing the math.

Measuring mass directly is far too expensive for a simple bathroom scale.

In your rocket example was the accelerating force 20 N, or the equivalent force of 20 kg on earth with 1 G ?

Again, what formula(s) did you use to arrive at apprx. 18-20 days for your 200 T spaceship..
 

CasualBystander

Celestial
In your rocket example was the accelerating force 20 N, or the equivalent force of 20 kg on earth with 1 G ?

Again, what formula(s) did you use to arrive at apprx. 18-20 days for your 200 T spaceship..

Kilogram is a unit of mass. Mass doesn't exert force. Pounds isn't mass either. Pounds is force. 190 pounds is 5.905381 slugs.

Only english system scales are honest since the scale is measuring weight not mass.


I made the simple assumption of constant acceleration. If you integrate acceleration against time you get velocity. V = a*t.

If you integrate velocity against time you get distance. D = 1/2 * a * t * t + Vo.

I assumed Vo was zero to eliminate some complex explanations and assumptions.

If you have to apply retrograde thrust the peak and average velocity is 50% lower and the trip takes twice as long. We will have some residual velocity particularly if we attack mars from its vulnerable backside. So the trip won't quite take twice as long.
 
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3FEL9

Islander
Only english system scales are honest since the scale is measuring weight not mass.

Only the metric system together with SI units are logical.. Didnt NASA and ESA screw something really expensive up in space a few years back,because the engineers mixed metric with imperial..

On a sidenote,, How come you did start to calculate spacetravel in the first place.. Verifying NASA's missions or something else ¿
 

CasualBystander

Celestial
In your rocket example was the accelerating force 20 N, or the equivalent force of 20 kg on earth with 1 G ?

Again, what formula(s) did you use to arrive at apprx. 18-20 days for your 200 T spaceship..

Update: math error (actually a units error)

The time to beat is 130 to 260 days.

The thrust really does have to be about 1/1000th of rocket thrust or 900 Newtons and this gives about 56 days.

But now this gets into a question of leveraging the initial orbital velocity and manipulating it (we weren't actually starting from zero). The sensible thing is to do a translunar injection orbit and do a moon flyby to get you on the way to Mars.

And it should be noted that most of a 200 tonne conventional space vehicle would have to be fuel for the journey there or back.

Only the metric system together with SI units are logical.. Didnt NASA and ESA screw something really expensive up in space a few years back,because the engineers mixed metric with imperial..

On a sidenote,, How come you did start to calculate spacetravel in the first place.. Verifying NASA's missions or something else ¿

Because of all the "it won't work we didn't go there" I computed the fuel requirement for the lunar module to ascend and mate with the command module.

It turns out that they had a couple of hundred pounds of reserve fuel. But there is a reason it looked like the takeoff was skimming the moon. To minimize fuel you popup a couple of hundred feet and then fly almost sidewise to put as much fuel as possible into gaining orbital velocity instead of fighting gravity.
 
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CasualBystander

Celestial
Didnt NASA and ESA screw something really expensive up in space a few years back,because the engineers mixed metric with imperial..

Small forces file.

The way they determine speed and position of robot spacecraft is known original velocity/position + all the thruster firings to correct spacecraft attitude.

This is the small forces file.

For Mars Observer the software that computed small forces used english units. The AMD software that computed trajectory used the data from the small forces file and assumed metric. Further the spacecraft was asymmetric and there were more firings than expected.

The computed trajectory was about 170 miles further from Mars than the actual spacecraft. At the time of the insertion burn the actual spacecraft had probably already been inserted into the planet.
 

CasualBystander

Celestial
Mars Observer

Correction: Mars Climate Orbiter.

Mars Observer was a different screw-up.

The wiki page is a little different than I remember. My memory is something like this.

The fuel system wasn't supposed to be pressurized until Mars and they pressurized it in earth orbit. Fuel leaked past the valves during the trip.

When they got to Mars they shutdown telemetry (to avoid some problem like the impact of the firing on instruments or electronics) and commanded the burn. The fuel lines ruptured, splashed corrosive fuel over the inside of the spacecraft and either spun it fast enough to enter contingency mode - which canceled the command to turn the transmitter back on, or simply damaged the spacecraft (the people I knew were in the small detonation camp).

It is wandering through the ether somewhere.
 

CasualBystander

Celestial
Read somewhere that they thought Aliens were taking the probes from Mars orbit ? Not all of them but a few. No one seemed to know where the probes went .

Phobos II is the odd one.

The spacecraft took a picture of something coming from Phobos as I recall then everything went black.

There is at least one picture of something spaceshipy in appearance near Phobos.

Site says the final three frames were interesting.
Flashback 1989: Mars Mission – Phobos II Probe – Russians Confirmed UFO Photographed !
 

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