Adjusting the orbit of a spacecraft by giving it an electric charge and then it's forced in a given direction by the Earth's magnetic field.

[Maximillian]

No need of long electrodynamic tethers and so will enable a small foot print and low maintenance costs.
No need of power to run current through the tethers at all times to boost orbital velocity since we are already charged.
How viable is my proposal?

[Strange]

How viable is my proposal?

 

You tell us. For example, have you worked out how much force will be generated? And at what cost?

[Maximillian]

 

You tell us. For example, have you worked out how much force will be generated? And at what cost?

Taking a spacecraft of 10^-4Farads and a pd of 100,000 volts we can generate a force of 10Newtons on the spacecraft. This force is clearly more than ion thruster engines. The fact that we won't need any reaction mass makes it more cheaper and also stay in orbit indefinitely. Once we have the spacecraft charged by applying a pd across it, no more energy is needed to move it and so it will move on it's own.

Edited March 15, 2016 by Maximillian

[EdEarl]

I think the charge will drain away slowly as photons hit the charged surface of the orbiter.

[swansont]

Taking a spacecraft of 10^-4Farads and a pd of 100,000 volts we can generate a force of 10Newtons on the spacecraft. This force is clearly more than ion thruster engines. The fact that we won't need any reaction mass makes it more cheaper and also stay in orbit indefinitely. Once we have the spacecraft charged by applying a pd across it, no more energy is needed to move it and so it will move on it's own.

 

 

You said magnetic field, but regardless, where would this 100 kV potential come from, free of energy?

[Maximillian]

 

 

You said magnetic field, but regardless, where would this 100 kV potential come from, free of energy?

This energy can come from solar panels, that will be used in the charging process, if not charging can be done from Earth before launch.

I think the charge will drain away slowly as photons hit the charged surface of the orbiter.

Photons are massless and can't produce friction to discharge the orbiter.

Edited March 17, 2016 by Maximillian

[EdEarl]

http://ocw.mit.edu/courses/nuclear-engineering/22-01-introduction-to-ionizing-radiation-fall-2006/lecture-notes/energy_dep_photo.pdf

 

Sometimes a photon transfers its momentum to a free electron or other mass and makes it move. Friction isn't required.

 

Moreover, a high negative potential repels electrons, and any sharp points or edges will leak electrons from being repelled by the high negative potential. Light just makes the process go faster. See Wikipedia Electron Gun

 

BTW, quantum particles like electrons do not experience friction, and friction is not the cause of static electricity when rubbing your feet across a carpet.

Edited March 17, 2016 by EdEarl

[John Cuthber]

Space is conductive.

[Maximillian]

http://ocw.mit.edu/courses/nuclear-engineering/22-01-introduction-to-ionizing-radiation-fall-2006/lecture-notes/energy_dep_photo.pdf

 

Sometimes a photon transfers its momentum to a free electron or other mass and makes it move. Friction isn't required.

 

Moreover, a high negative potential repels electrons, and any sharp points or edges will leak electrons from being repelled by the high negative potential. Light just makes the process go faster. See Wikipedia Electron Gun

 

BTW, quantum particles like electrons do not experience friction, and friction is not the cause of static electricity when rubbing your feet across a carpet.

A positive potential is convenient to prevent discharge. Yes your right the photons can eject electrons but that will be to our advantage to achieve a positive potential.

Edited March 17, 2016 by Maximillian

[John Cuthber]

A positive potential is convenient to prevent discharge.

Not really. "space" is conductive

[Carrock]

Taking a spacecraft of 10^-4Farads and a pd of 100,000 volts we can generate a force of 10Newtons on the spacecraft. This force is clearly more than ion thruster engines. The fact that we won't need any reaction mass makes it more cheaper and also stay in orbit indefinitely. Once we have the spacecraft charged by applying a pd across it, no more energy is needed to move it and so it will move on it's own.

Creating a spacecraft with a 100 microFarad capacitance at 100kV is a few orders of magnitude beyond current technology.....

[John Cuthber]

An isolated sphere about a thousand km in diameter (which is, indeed outside our current capability) would do- but the problem still remains that, because "space" is conductive, you still need to supply power to maintain the voltage.

 

The moon is pretty close to 100µF

http://electronics.stackexchange.com/questions/111582/capacitance-between-earth-and-moon

but we need it for other things.

[Gavilan]

Magnetic Torqueing using the interaction between earths dipolar magnetic field and on-board coils has been used since the 1960's.

 

The step from Newtonian Impulse Fuels to Magnetic Field Propulsion was probably taken some time ago.

 

Propulsion without the use of Newtonian propellants is a paradigm shift. This does not change the relationship of input energy to the change in gravitational and translational energy; but it most definitely changes the mass and volume fractions for deep space missions.

 

The ability to alter orbital energy using magnetic field interaction and electro-dynamic braking utilizing the magnetic fields of the Sun and Planets changes everything.

 

When considering asteroid deflection it allows the orbital energy of the asteroid itself to become the prime energy source for changing orbital intersect.

Edited April 5, 2016 by Gavilan

[Enthalpy]

Taking a spacecraft of 10^-4Farads and a pd of 100,000 volts we can generate a force of 10Newtons on the spacecraft.

No. This is not how electrostatic force is computed.

https://en.wikipedia.org/wiki/Coulomb%27s_law

If you put figures on it, you find a minute force. In addition, it's in the wrong direction.

Edited April 5, 2016 by Enthalpy